Reliability Standard IRO-006-WECC-1

June 17, 2009
VIA ELECTRONIC FILING
Ms. Kimberly D. Bose
Secretary
Federal Energy Regulatory Commission
888 First Street, NE
Washington, D.C. 20426
Re: North American Electric Reliability Corporation
Docket Nos. RM09-__-000
Dear Ms. Bose:
The North American Electric Reliability Corporation (“NERC”) hereby submits
this petition in accordance with Section 215(d)(1) of the Federal Power Act (“FPA”) and
Part 39.5 of the Federal Energy Regulatory Commission’s (“FERC” or the
“Commission”) regulations seeking approval of one proposed regional Reliability
Standard of the Western Electricity Coordinating Council (“WECC”), IRO-006-WECC-1
- Qualified Transfer Path Unscheduled Flow (USF) Relief and six associated new
definitions included below and set forth in Exhibit A to this petition:
 Contributing Schedule: A Schedule not in the Qualified Transfer Path
between a Source Balancing Authority and a Sink Balancing Authority that
contributes unscheduled flow across the Qualified Transfer Path.
 Qualified Transfer Path: A transfer path designated by the WECC Operating
Committee as being qualified for WECC unscheduled flow mitigation.
 Qualified Controllable Device: A controllable device installed in the
Interconnection for controlling energy flow; the WECC Operating Committee
has approved using the device for controlling the USF on the Qualified
Transfer Paths.

Ms. Kimberly D. Bose
June 17, 2009
Page Two
 Qualified Transfer Path Curtailment Event: Each hour that a Transmission
Operator calls for Step 4 or higher for one or more consecutive hours (See
Attachment 1 IRO-006-WECC-1) during which the curtailment tool is
functional.
 Relief Requirement: The expected amount of the unscheduled flow reduction
on the Qualified Transfer Path that would result by curtailing each Sink
Balancing Authority’s Contributing Schedules by the percentages listed in the
columns of WECC Unscheduled Flow Mitigation Summary of Actions Table
in Attachment 1 WECC IRO-006-WECC-1.
 Transfer Distribution Factor (TDF): The percentage of USF that flows
across a Qualified Transfer Path when an Interchange Transaction
(Contributing Schedule) is implemented. [See the WECC Unscheduled Flow
Mitigation Summary of Actions Table (Attachment 1 WECC IRO-006WECC-1).]
The proposed regional Reliability Standard was approved by the NERC Board of
Trustees during its February 10, 2009 meeting. NERC requests an effective date of the
first day of the first quarter after applicable U.S. regulatory and Canadian regulatory
approval where appropriate.
This petition consists of the following:








this transmittal letter;
a table of contents for the entire petition;
a narrative description explaining how the proposed regional Reliability
Standard meets the Commission’s requirements;
regional Reliability Standard, IRO-006-WECC-1 Qualified Transfer Path
Unscheduled Flow (USF) Relief, submitted for approval (Exhibit A);
the NERC Board of Trustees’ Resolution on IRO-006-WECC-1 Qualified
Transfer Path Unscheduled Flow (USF) Relief (Exhibit B);
the complete development record of the proposed regional Reliability
Standard (Exhibit C); and
the Standard Drafting Team roster (Exhibit D).

Please contact the undersigned if you have any questions.
Respectfully submitted,

/s/ Holly A. Hawkins
Holly A. Hawkins
Attorney for North American Electric
Reliability Corporation

UNITED STATES OF AMERICA
BEFORE THE
FEDERAL ENERGY REGULATORY COMMISSION

NORTH AMERICAN ELECTRIC RELIABILITY
CORPORATION

) Docket Nos. RM09-__-000
)

PETITION OF THE
NORTH AMERICAN ELECTRIC RELIABILITY CORPORATION
FOR APPROVAL OF PROPOSED WESTERN ELECTRICITY
COORDINATING COUNCIL REGIONAL RELIABILITY STANDARD
IRO-006-WECC-1 QUALIFIED TRANSFER PATH UNSCHEDULED FLOW
(USF) RELIEF

Rick Sergel
President and Chief Executive Officer
David N. Cook
Vice President and General Counsel
North American Electric Reliability
Corporation
116-390 Village Boulevard
Princeton, NJ 08540-5721
(609) 452-8060
(609) 452-9550 – facsimile
[email protected]

June 17, 2009

Rebecca J. Michael
Assistant General Counsel
Holly A. Hawkins
Attorney
North American Electric Reliability
Corporation
1120 G Street, N.W.
Suite 990
Washington, D.C. 20005-3801
(202) 393-3998
(202) 393-3955 – facsimile
[email protected]
[email protected]

TABLE OF CONTENTS
I. Introduction..............................................................................................................1
II. Notices and Communications……………………………………………………..2
III. Background:.............................................................................................................2
a. Regulatory Framework ...............................................................................2
b. Basis for Approval of Additional Proposed Reliability Standards............. 2
c. Reliability Standards Development Procedure .......................................... 3
d. Progress in Improving Proposed Reliability Standards ..............................4
IV. Justification for Approval of the Proposed Reliability Standard.............................5
a. Basis and Purpose of IRO-006-WECC-1 Qualified Transfer Path
Unscheduled Flow (USF) Relief………………………………………….5
V. Summary of the Reliability Standard Development Proceedings………………..24
a. Development History…………………………………………………….24
b. Key Issues………………………………………………………………. 26
VI. Conclusion ................................................................................................. ..........29
Exhibit A – Reliability Standard Proposed for Approval
Exhibit B – The NERC Board of Trustees’ Resolution on the WECC Regional
Reliability Standard
Exhibit C – Record of Development of Proposed WECC Regional Reliability
Standard
Exhibit D – Standard Drafting Team Roster

I.

INTRODUCTION
The North American Electric Reliability Corporation (“NERC”) 1 hereby requests

the Federal Energy Regulatory Commission (the “Commission” or “FERC”) to approve,
in accordance with Section 215(d)(1) of the Federal Power Act (“FPA”) 2 and Section
39.5 of the Commission’s regulations, 18 C.F.R. § 39.5, one regional Reliability
Standard, IRO-006-WECC-1 - Qualified Transfer Path Unscheduled Flow (USF) Relief
and six associated new definitions of the following terms, which are included in Exhibit
A, and are identified below:







Contributing Schedule
Qualified Transfer Path
Qualified Controllable Device
Qualified Transfer Path Curtailment Event
Relief Requirement
Transfer Distribution Factor

The regional Reliability Standard proposed by the Western Electricity
Coordinating Council (“WECC”) will be in effect only within the Western
Interconnection. These Regional Entity definitions will be included in NERC’s Glossary
of Terms and will explicitly state that the terms only apply within WECC. This petition
is the first request by NERC for Commission approval of this proposed Regional
Reliability Standard.
On February 10, 2009, the NERC Board of Trustees approved IRO-006-WECC-1,
Qualified Transfer Path Unscheduled Flow (USF) Relief, a regional Reliability Standard
proposed by WECC. NERC requests that the Commission approve this WECC regional
Reliability Standard and make it effective the first day of the first quarter after
1

NERC has been certified by the Commission as the electric reliability organization (“ERO”) authorized
by Section 215 of the Federal Power Act. The Commission certified NERC as the ERO in its order issued
July 20, 2006 in Docket No. RR06-1-000. 116 FERC ¶ 61,062 (2006) (“ERO Certification Order).
2
16 U.S.C. 824o.

Commission approval to be effective within the U.S. portion of the WECC Regional
Entity. NERC also is filing this regional Reliability Standard with applicable
governmental authorities in Canada. Exhibit A to this filing sets forth the proposed
WECC regional Reliability Standard. Exhibit B is the NERC Board of Trustees’
Resolution to approve the proposed WECC regional Reliability Standard. Exhibit C
contains the complete record of development for the proposed WECC regional Reliability
Standard that includes WECC’s development and approval process prior to submitting
the proposed standard to NERC, WECC’s submittal request to NERC for evaluation of its
proposed regional Reliability Standard, NERC’s response and evaluation of the proposed
regional Reliability Standard, and the comments received during the industry-wide
comment period NERC conducted on the proposed WECC regional Reliability Standard.
Exhibit D includes WECC’s standard drafting team roster.
II.

NOTICES AND COMMUNICATIONS
Notices and communications with respect to this filing may be addressed to the

following:
Rick Sergel
President and Chief Executive Officer
David N. Cook*
Vice President and General Counsel
North American Electric Reliability Corporation
116-390 Village Boulevard
Princeton, NJ 08540-5721
(609) 452-8060
(609) 452-9550 – facsimile
[email protected]
*Persons to be included on the Commission’s service list
are indicated with an asterisk. NERC requests waiver of
the Commission’s rules and regulations to permit the
inclusion of more than two people on the service list.

2

Rebecca J. Michael*
Assistant General Counsel
Holly A. Hawkins*
Attorney
North American Electric Reliability
Corporation
1120 G Street, N.W.
Suite 990
Washington, D.C. 20005-3801
(202) 393-3998
(202) 393-3955 – facsimile
[email protected]

III.

BACKGROUND
a. Regulatory Framework
By enacting the Energy Policy Act of 2005, 3 Congress entrusted FERC with the

duties of approving and enforcing rules to ensure the reliability of the Nation’s bulk
power system, and with the duties of certifying an ERO that would be charged with
developing and enforcing mandatory Reliability Standards, subject to Commission
approval. Section 215 states that all users, owners and operators of the bulk power
system in the United States will be subject to the Commission-approved Reliability
Standards.
b. Basis for Approval of Proposed Regional Reliability Standard
Section 39.5(a) of the Commission’s regulations requires the ERO to file with the
Commission for its approval each Reliability Standard that the ERO proposes to become
mandatory and enforceable in the United States, and each modification to a Reliability
Standard that the ERO proposes to be made effective. The Commission has the
regulatory responsibility to approve standards that protect the reliability of the bulk
power system. In discharging its responsibility to review, approve and enforce
mandatory Reliability Standards, the Commission is authorized to approve those
proposed Reliability Standards that meet the criteria detailed by Congress:
The Commission may approve, by rule or order, a proposed reliability
standard or modification to a reliability standard if it determines that the
standard is just, reasonable, not unduly discriminatory or preferential, and
in the public interest. 4
When evaluating proposed Reliability Standards, the Commission is expected to
give “due weight” to the technical expertise of the ERO and to the technical expertise of a
3
4

16 U.S.C. § 824o.
16 U.S.C. § 824o(d)(2).

3

Regional Entity organized on an Interconnection-wide basis with respect to a Reliability
Standard to be applicable within that Interconnection. Order No. 672 provides guidance
on the factors the Commission will consider when determining whether proposed
Reliability Standards meet the statutory criteria. 5
A Reliability Standard proposed by a Regional Entity must meet the same
standards that NERC’s Reliability Standards must meet, i.e., the regional Reliability
Standard must be shown to be just, reasonable, not unduly discriminatory or preferential,
and in the public interest. 6 If the regional Reliability Standard is proposed by a Regional
Entity organized on an Interconnection-wide basis to be applicable on an
Interconnection-wide basis, then NERC (but not the Commission) must rebuttably
presume that the standard is just, reasonable, not unduly discriminatory or preferential,
and in the public interest. 7
The Commission’s Order No. 672 establishes two additional criteria that a
regional standard must satisfy: A regional difference from a continent-wide Reliability
Standard must either be (1) more stringent than the continent-wide Reliability Standard
(which includes a regional standard that addresses matters that the continent-wide
Reliability Standard does not), or (2) a regional Reliability Standard that is necessitated
by a physical difference in the bulk-power system. 8

5

See Rules Concerning Certification of the Electric Reliability Organization; Procedures for the
Establishment, Approval and Enforcement of Electric Reliability Standards, FERC Stats. & Regs., ¶ 31,204
at PP 320-338 (“Order No. 672”), order on reh’g, FERC Stats. & Regs. ¶ 31,212 (2006) (“Order No. 672A”).
6
Section 215(d)(2) of the FPA and 18 C.F.R. §39.5(a).
7
See Section 215(d)(3) of the FPA and 18 C.F.R. §39.5(b).
8
Order No. 672 at P 291.

4

c. Regional Reliability Standards Development Procedure
Section 311 of the NERC Rules of Procedure enables a Regional Entity to
develop regional Reliability Standards that become mandatory and enforceable upon
Commission approval. WECC’s Process for Developing and Approving WECC
Standards is included as Exhibit C of the Delegation Agreement between NERC and
WECC, and was originally approved by FERC on April 19, 2007, 9 approved as amended
on March 21, 2008, 10 and approved as further amended on December 19, 2008. 11
Section 312 of the NERC Rules of Procedure provides that NERC shall rebuttably
presume that a regional Reliability Standard to be applied on an Interconnection-wide
basis that is developed by a Regional Entity organized on an Interconnection-wide basis
is just, reasonable, and not unduly discriminatory or preferential, and in the public
interest, and consistent with such other applicable standards of governmental
authorities. 12
Section 312 of the NERC Rules of Procedure also establishes other factors for the
NERC Board of Trustees to consider in acting on a request to approve proposed Regional
Standards. The NERC Board of Trustees must consider the Regional Entity’s request,
NERC’s recommendation for action on the regional Reliability Standard, any unresolved
stakeholder comments, and the Regional Entity’s consideration of the comments in
determining whether to approve the regional Reliability Standard as a NERC Reliability
Standard. 13

9

Order Accepting ERO Compliance Filing, Accepting ERO/Regional Entity Delegation Agreements, and
Accepting Regional Entity 2007 Business Plans, 116 FERC ¶ 61,062 at P 469.
10
Order Addressing Revised Delegation Agreements, 122 FERC ¶ 61,245 at P 225.
11
Order Accepting Compliance Filings, Subject to Conditions, 125 FERC ¶ 61,330.
12
NERC Rules of Procedure at Section 312.
13
NERC Rules of Procedure at Section 312.3.1.

5

On June 10, 2008, WECC submitted a request to NERC to approve, and submit to
FERC for approval, IRO-006-WECC-1 - Qualified Transfer Path Unscheduled Flow
(USF) Relief, the proposed regional Reliability Standard that is the subject of this
petition. WECC developed this standard following its Process for Developing and
Approving WECC Standards (“WECC Process”). WECC is organized on an
Interconnection-wide basis and the proposed standard will be applicable on an
Interconnection-wide basis. Therefore, NERC rebuttably presumes it is just, reasonable,
and not unduly discriminatory or preferential, and in the public interest. Further, WECC
stated, and NERC agrees, that the proposed WECC regional Reliability Standard
establishes requirements that are more stringent than or covers areas not covered by
current NERC Reliability Standards thereby meeting the Commission criteria for
consideration of a Regional Standard.
Upon receipt of WECC’s request, NERC commenced an evaluation of the
regional Reliability Standard and initiated a 45-day public comment period, as prescribed
by Section 312 of NERC’s Rules of Procedures. WECC responded to the comments
presented during the NERC posting and requested NERC to present the WECC regional
Reliability Standard for NERC Board of Trustees approval.
During this evaluation, NERC identified a shortcoming in the standard, namely
that the proposed standard includes a defined term for Transfer Distribution Factor
(“TDF”) that conflicts with the NERC defined term in the NERC Glossary of Terms.
WECC acknowledged this inconsistency in its response to NERC’s comments. WECC
and NERC agreed to address the inconsistency in defined terms by proposing a
modification to the NERC defined term using the standards development process with the

6

intent that the modified definition would be technically sufficient for use within WECC
and the entirety of North America. In the interim, the proposed defined term for TDF
will be effective within WECC only. NERC’s evaluation of the proposed regional
Reliability Standard is available in Exhibit C. The proposed WECC regional Reliability
Standard was approved by the NERC Board of Trustees on February 10, 2009, for filing
with the Commission and applicable governmental authorities in Canada.
d. Progress in Improving Proposed Reliability Standards
On June 8, 2007 in the Order Approving Regional Reliability Standards for the
Western Interconnection and Directing Modifications (“June 8 Order”), the Commission
approved, with conditions, eight WECC Tier 1 Reliability Management System (“RMS”)
Regional Reliability Standards stating that the reliability of the bulk power system of the
Western Interconnection is best served by their implementation. 14 The Commission
approved the following WECC Regional Entity standards in the June 8 Order:


BAL-STD-002-0 — Operating Reserves



IRO-STD-006-0 — Qualified Path Unscheduled Flow Relief



PRC-STD-001-1 — Certification of Protective Relay Applications and
Settings



PRC-STD-003-1 — Protective Relay and Remedial Action Scheme
Misoperation



PRC-STD-005-1 — Transmission Maintenance



TOP-STD-007-0 — Operating Transfer Capability



VAR-STD-002a-1 — Automatic Voltage Regulators



VAR-STD-002b-1 — Power System Stabilizers

14

North American Electric Reliability Corporation, “Order Approving Regional Reliability Standards for
the Western Interconnection and Directing Modifications,” 119 FERC ¶ 61,260 (2007).

7

In addition, the Commission directed WECC to develop several modifications to
the regional Reliability Standards when WECC develops, through its Reliability
Standards development process, permanent, replacement Reliability Standards, including
the following:
(1) remove the one-year term limitation;
(2) address the shortcomings in the standards within one year of approval by the
Commission, including removing the sanctions table that conflicts with the
NERC Sanction Guidelines;
(3) until the WECC sanction table is removed, follow the NERC Sanction
Guidelines to the maximum extent possible within the limits of the WECC
sanction table; and
(4) monitor and enforce the standards under a delegation agreement between
NERC and WECC, once that agreement is approved. 15
In addition to these general directives, the Commission directed WECC to
develop a replacement for the IRO-STD-006-0 Qualified Path Unscheduled Flow (USF)
Relief Reliability Standard, to clarify the term “receiver” used in the standard, and to
address the concerns with identifying Load Serving Entities in the applicability of the
standard. The Commission also directed WECC to meet its commitment to address the
shortcomings identified during the NERC review, including formatting concerns and the
inconsistency between NERC and WECC’s definition of the term “disturbance.”
In June 2008, WECC submitted seven proposed Regional Reliability Standards to
replace the eight original Reliability Standards that the Commission approved in 2007,
one of which, IRO-006-WECC-1, is the subject of this filing. 16 WECC used the same
WECC Process, described above, in developing this proposed standard. NERC
confirmed that WECC followed the process approved in its Commission-approved

15

Id. at P 16.
The six remaining WECC Regional Entity standards were submitted to NERC, approved by the Board of
Trustees, and filed with the Commission for approval in February and March, 2009.
16

8

Regional Delegation Agreement with NERC in developing the replacement standard that
is proposed in this filing.
In addition to addressing the Commission’s concerns noted in the June 8 Order,
WECC made substantial technical modifications to the proposed standard IRO-006WECC-1 on its own accord to fully address the Commission’s concerns regarding the
applicability of Load Serving Entities and with the use of the “receiver.” NERC
continues to rebuttably presume these modifications to the standard are just, reasonable,
and not unduly discriminatory or preferential, and in the public interest.
The proposed WECC regional Reliability Standard is to be applied on an
interconnection-wide basis. Because there was no strong technical objection from
commenters, and because the regional Reliability Standard was developed by those from
the Western Interconnection to apply in the Western Interconnection through a process
that enabled all those with an interest in the standards to be heard, NERC does not object
to the technical merits of the proposed regional Reliability Standard. Additionally,
NERC’s public posting of this proposed regional Reliability Standard did not elicit any
significant technical objection. Further, considering the proposed standard on its merits,
NERC agrees that the proposed standard meets the criteria for consideration and approval
as a regional Reliability Standard.

IV.

JUSTIFICATION FOR APPROVAL OF PROPOSED RELIABILITY
STANDARD
This section summarizes the development of the proposed regional Reliability

Standard IRO-006-WECC-1, describes the reliability objectives to be achieved by
approving the regional Reliability Standard, explains the development history of the

9

Reliability Standard, and explains how the standard meets the criteria for approval set by
the Commission. NERC, in its analysis of the proposed regional Reliability Standard,
determined that the standard is just, reasonable, not unduly discriminatory or preferential,
and in the public interest.
The complete development record for the proposed Reliability Standard is
provided in Exhibit C and includes the WECC development and approval process,
comments received during the industry-wide comment period NERC conducted on the
proposed standard, WECC’s responses to those comments, WECC ballot information,
WECC’s submittal request to NERC for evaluation of the proposed regional Reliability
Standard and NERC’s evaluation of the proposed standard.
a. Basis and Purpose of IRO-006-WECC-1 — Qualified Transfer Path
Unscheduled Flow (USF) Relief
The primary purpose of this regional Reliability Standard is to mitigate
transmission overloads due to unscheduled flow on Qualified Transfer Paths. In the
proposed IRO-006-WECC-1 standard, responsibility for initiating schedule curtailment is
assigned to the Reliability Coordinators, and the responsibility for implementing the
curtailments is assigned to Balancing Authorities. This regional Reliability Standard is
intended to create a permanent replacement standard for IRO-STD-006-0 that was
approved by the Commission in June 2007. IRO-006-WECC-1 is designed to implement
the directives of FERC from its order approving the regional standard, taking into
consideration recommendations from NERC, and incorporating other changes WECC
determined were necessary.
As explained in Section 312.1 of NERC’s Rules of Procedure, “[r]egional entities
may propose regional reliability standards that set more stringent reliability requirements

10

than the NERC reliability standard or cover matters not covered by an existing NERC
reliability standard.” 17 The proposed IRO-006-WECC-1 Regional Standard is justified
on the basis that the standard requirements are more stringent than the associated NERC
Reliability Standard IRO-006-4 - Transmission Loading Relief. Specifically, the NERC
continent-wide Reliability Standard IRO-006-4 Reliability Standard requires a Reliability
Coordinator experiencing a potential or actual System Operating Limit (“SOL”) or
Interconnection Reliability Operating Limit (“IROL”) violation to take appropriate
actions to relieve transmission loading relief using local or Interconnection-wide
procedures (Requirement R1). However, the proposed regional Reliability Standard goes
beyond the NERC requirements by establishing a process to reduce schedules that
prevent potential overloads during the next operating hour. Furthermore, IRO-006WECC-1 R1 requires each Reliability Coordinator to approve (actively or passively) or
deny a request submitted by a Transmission Operator of a Qualified Transfer Path (for
Step 4 or higher as described in Attachment 1 to the Regional Entity standard) within
five minutes. IRO-006-WECC-1 Requirement R2 requires each Balancing Authority to
approve the curtailment requests to the schedules as submitted, implement alternative
actions, or a combination thereof, that collectively meet the Relief Requirement.
Accordingly, NERC agrees that the proposed IRO-006-WECC-1 regional Reliability
Standard meets the criteria for approval, and recommends Commission approval because
it serves a valuable reliability purpose.

17

NERC Rules of Procedure at Section 312.1.

11

Demonstration that the proposed Reliability Standard is just,
reasonable, not unduly discriminatory or preferential and in the public
interest
In Order No. 672, the Commission identified a number of criteria it will use to
analyze Reliability Standards proposed for approval to ensure they are just, reasonable,
not unduly discriminatory or preferential, and in the public interest. The discussion
below identifies these factors and explains how the proposed regional Reliability
Standard has met or exceeded the criteria:
1. Proposed Reliability Standards must be designed to achieve a specified
reliability goal
Order No. 672 at P 321. The proposed Reliability Standard must address a
reliability concern that falls within the requirements of section 215 of the
FPA. That is, it must provide for the reliable operation of Bulk-Power System
facilities. It may not extend beyond reliable operation of such facilities or
apply to other facilities. Such facilities include all those necessary for
operating an interconnected electric energy transmission network, or any
portion of that network, including control systems. The proposed Reliability
Standard may apply to any design of planned additions or modifications of
such facilities that is necessary to provide for reliable operation. It may also
apply to Cybersecurity protection.
The proposed regional Reliability Standard, IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow (USF) Relief, is designed to achieve the specific
reliability goal of providing transmission loading relief to mitigate transmission overloads
due to unscheduled flow on Qualified Transfer Paths in the Western Interconnection.
Because of the physical nature of the Bulk Electric System in the Western
Interconnection, there are times when circulating flows, caused by schedules other than
those “on-path” schedules of the Transmission Operator (“TOP”) and outside the direct
control of the TOP, result in significant flows across the Qualified Paths, potentially
resulting in flows that exceed System Operating Limits (“SOLs”). In those situations

12

where the TOP has taken action to reduce the flows on a Qualified Path but, because of
Contributing Schedules, the flows are still near or exceeding the SOLs, IRO-006-WECC1 requires curtailment of Contributing Schedules or provision of comparable relief
through other means, so that the TOP of the Qualified Path can keep the actual flow
within the SOLs.
2. Proposed Reliability Standards must contain a technically sound method to
achieve the goal
Order No. 672 at P 324. The proposed Reliability Standard must be designed
to achieve a specified reliability goal and must contain a technically sound
means to achieve this goal. Although any person may propose a topic for a
Reliability Standard to the ERO, in the ERO’s process, the specific proposed
Reliability Standard should be developed initially by persons within the
electric power industry and community with a high level of technical expertise
and be based on sound technical and engineering criteria. It should be based
on actual data and lessons learned from past operating incidents, where
appropriate. The process for ERO approval of a proposed Reliability Standard
should be fair and open to all interested persons.
The proposed regional Reliability Standard, IRO-006-WECC-1 – Qualified Path
Unscheduled Flow Relief was developed by a drafting team comprised of experts in the
areas of electric grid operations and merchants from throughout the Western
Interconnection and contains a technically sound method to achieve its goal. IRO-006WECC-1 will replace the existing approved standard, IRO-STD-006-0. IRO-STD-006-0
was developed as a translation of the original WECC Reliability Management System
requirements and does not conform to the current NERC functional model. The existing
standard assigns Load Serving Entities (“LSEs”) the responsibility of curtailing schedules
to reduce unscheduled flow, a reliability function that the NERC functional model now
assigns to Reliability Coordinators and Balancing Authorities. In the functional model,
NERC does not assign these tasks to LSEs. Additionally, the existing IRO-STD-006-0

13

Regional Entity standard places the sole responsibility for providing relief upon the LSE
without providing the ability for the LSE to ensure compliance (e.g., the Balancing
Authority does not have to approve a curtailment request made by the LSE). When IROSTD-006-0 was approved, FERC directed WECC to address this concern in developing a
permanent replacement Reliability Standard.
In the proposed standard, IRO-006-WECC-1 – Qualified Path Unscheduled Flow
Relief, responsibility for initiating schedule curtailment is assigned to the Reliability
Coordinators and the responsibility for implementing the curtailments is assigned to
Balancing Authorities. The proposed regional Reliability Standard utilizes a similar
approach to the currently approved version but is aligned with the NERC functional
model to provide a comparable level of Contributing Schedule relief. However, it has
been revised to remove responsibilities for reliability from LSEs. The proposed standard
now reads:
R.1. Upon receiving a request of Step 4 or greater (see Attachment 1-IRO-006-WECC-1)
from the Transmission Operator of a Qualified Transfer Path, the Reliability
Coordinator shall approve (actively or passively) or deny that request within five
minutes. [Violation Risk Factor: Medium] [Time Horizon: Real-time Operations]
R.2. The Balancing Authorities shall approve curtailment requests to the schedules as
submitted, implement alternative actions, or a combination there of that collectively
meets the Relief Requirement. [Violation Risk Factor: Medium] [Time Horizon: Realtime Operations]

A Contributing Schedule is defined as a Schedule not on the Qualified Transfer
Path between a Source Balancing Authority and a Sink Balancing Authority that
contributes unscheduled flow across the Qualified Transfer Path. In the Western
Interconnection, the Transfer Distribution Factor (“TDF”) 18 is the percentage of

18

NERC defines TDF as “The portion of an Interchange Transaction, typically expressed in per unit that
flows across a transmission facility (Flowgate).” This is different than the definition used in the Western
Interconnection.

14

Unscheduled Flow that flows across the Qualified Transfer Path when an Interchange
Transaction (Contributing Schedule) is implemented. Technical studies identify the TDF
for Contributing Schedules across Qualified Transfer Paths. Relief Requirements,
curtailments to contributing schedules, or alternative actions, or a combination thereof
that collectively meet the Relief Requirement, are identified in Attachment 1, WECC
IRO-006-WECC-1, where the expected amount of unscheduled flow reduction on the
Qualified Transfer Path is identified based on the current step of the Unscheduled Flow
Mitigation Procedure and the TDF of the Contributing Schedule.
The proposed standard improves the efficiency of the program, provides for more
certain Unscheduled Flow relief, and results in fewer complications associated with
multiple entities taking partial responsibility for curtailment activity. For these reasons,
the proposed Reliability Standard is technically sound and is superior to the existing
approved IRO-STD-006-0 standard.
3. Proposed Reliability Standards must be applicable to users, owners and
operators of the bulk power system, and not others
Order No. 672 at P 322. The proposed Reliability Standard may impose a
requirement on any user, owner, or operator of such facilities, but not on
others.
The proposed regional Reliability Standard is applicable only to users, owners and
operators of the bulk power system located within WECC, and not others. As identified
in the applicability section of the proposed standard, the requirements in the proposed
regional Reliability Standards are only applicable to Balancing Authorities and
Reliability Coordinators within the Western Interconnection. No Balancing Authorities
or Reliability Coordinators outside of WECC or other registered entities within WECC
are required to comply with these requirements.

15

4. Proposed Reliability Standards must be clear and unambiguous as to what is
required and who is required to comply
Order No. 672 at P 325. The proposed Reliability Standard should be clear
and unambiguous regarding what is required and who is required to comply.
Users, owners, and operators of the Bulk-Power System must know what they
are required to do to maintain reliability.
The proposed regional Reliability Standard applies exclusively to Balancing
Authorities and Reliability Coordinators within WECC. NERC’s Compliance Registry
identifies, by name, the specific entities registered for these two functions and therefore
the specific entities that are obligated to comply with the proposed standard.
The proposed regional Reliability Standard’s two requirements clearly and
unambiguously establish the applicable entities’ compliance obligations by: (1)
identifying that Reliability Coordinators determine whether or not action must be taken to
initiate the curtailment of Contributing Schedules as identified by the webSAS tool (a
computer program developed to identify Contributing Schedules and the required
curtailment amounts) in Requirement R1, and (2) requiring that Balancing Authorities
approve the curtailment requests initiated through the webSAS tool in Requirement R2.
5. Proposed Reliability Standards must include clear and understandable
consequences and a range of penalties (monetary and/or non-monetary) for a
violation
Order No. 672 at P 326. The possible consequences, including range of
possible penalties, for violating a proposed Reliability Standard should be
clear and understandable by those who must comply.
The proposed regional Reliability Standard includes a Violation Risk Factor and
Violation Severity Level for each main requirement in the proposed regional Reliability
Standard. Upon approval by the Commission, the ranges of penalties for violations will
be based on the applicable Violation Risk Factor and Violation Severity Level and will be

16

administered based on the sanctions table and supporting penalty determination process
described in the Commission-approved NERC Sanction Guidelines, Appendix 4B in
NERC’s Rules of Procedure.
6. Proposed Reliability Standards must identify clear and objective criterion or
measure for compliance, so that it can be enforced in a consistent and nonpreferential manner
Order No. 672 at P 327. There should be a clear criterion or measure of
whether an entity is in compliance with a proposed Reliability Standard. It
should contain or be accompanied by an objective measure of compliance so
that it can be enforced and so that enforcement can be applied in a consistent
and non-preferential manner.
Section C of the proposed regional Reliability Standard contains individual
measures that support both of the standard’s requirements by clearly identifying what is
required and how the requirement will be enforced. These two measures ensure the
requirements will be enforced in a clear, consistent, and non-preferential manner and
without prejudice to any party. Measurement M1 requires Reliability Coordinators to
have evidence that it approved or denied any transmission loading relief requests within
five minutes. Measurement M2 requires that Balancing Authorities have evidence that
they provided the Relief Requirement through Contributing Schedules curtailments,
alternative actions, or a combination that collectively meets the Relief Requirement
necessary to reduce flow on the Qualified Path.
Furthermore, to aid in the compliance monitoring process, a Reliability Standard
Audit Worksheet (“RSAW”) will be developed for this proposed regional Reliability
Standard once it is approved. RSAWs also assist the applicable registered entity in
understanding what the entity is expected to provide in support of the particular measures
to demonstrate compliance.

17

7. Proposed Reliability Standards should achieve a reliability goal effectively and
efficiently - but does not necessarily have to reflect “best practices” without
regard to implementation cost
Order No. 672 at P 328. The proposed Reliability Standard does not
necessarily have to reflect the optimal method, or “best practice,” for
achieving its reliability goal without regard to implementation cost or
historical regional infrastructure design. It should however achieve its
reliability goal effectively and efficiently.
The proposed regional Reliability Standard requires a level of transmission
loading relief sufficient to ensure reliable operation of the Bulk Electric System in the
Western Interconnection similar to that required under the existing WECC regional
Reliability Standard. The proposed standard clearly identifies the required actions by the
Reliability Coordinators and Balancing Authorities. As directed by FERC, the conflicts
with the NERC Functional Model in the existing regional Reliability Standard, that is, the
assignment of reliability functions to the LSE, have been corrected. These improvements
better enable the proposed standard to achieve the stated reliability goal.
On the whole, the total aggregate cost to the applicable entities should remain the
same as the existing level of curtailments because the curtailment relief requirement
remains the same. The proposed regional Reliability Standard clarifies that the Balancing
Authority is responsible for approving curtailment requests, or implementing alternative
actions, to provide the necessary Relief Requirement. The drafting team developed a
clear approach, which moderates potential cost shifts while ensuring adequate overall
reliability equal to the existing standard. Identifying the Reliability Coordinator, the
entity with the wide area reliability view, as the entity responsible for approving or
denying the request for Step 4 or greater of the WECC Unscheduled Flow Mitigation
procedure, and identifying the Balancing Authority as the responsible entity for

18

approving curtailments, rather than identifying the LSE as the entity responsible for
providing relief, results in improved reliability. Ultimately, the proposed regional
Reliability Standard that contains this modified approach was approved by WECC’s
Operating Committee and Board of Directors.
8. Proposed Reliability Standards cannot be “lowest common denominator,” i.e.,
cannot reflect a compromise that does not adequately protect bulk power system
reliability

Order No. 672 at P 329. The proposed Reliability Standard must not simply
reflect a compromise in the ERO’s Reliability Standard development process
based on the least effective North American practice — the so-called “lowest
common denominator” — if such practice does not adequately protect BulkPower System reliability. Although the Commission will give due weight to
the technical expertise of the ERO, we will not hesitate to remand a proposed
Reliability Standard if we are convinced it is not adequate to protect
reliability.
While NERC standard IRO-006-4 – Transmission Loading Relief requires the
Reliability Coordinator to provide transmission loading relief using one or more
procedures, the proposed regional Reliability Standard requires the Reliability
Coordinator to approve or deny requests for relief and the Balancing Authority to
approve curtailment requests, implement alternative actions, or a combination there of
that collectively meets the relief requirements to mitigate potential SOL violations and
provide Contributing Schedule curtailments to mitigate potential overloads.
9. Proposed Reliability Standards may consider costs to implement for smaller
entities but not at consequence of less than excellence in operating system
reliability

Order No. 672 at P 330. A proposed Reliability Standard may take into
account the size of the entity that must comply with the Reliability Standard
and the cost to those entities of implementing the proposed Reliability
Standard. However, the ERO should not propose a “lowest common
denominator” Reliability Standard that would achieve less than excellence in

19

operating system reliability solely to protect against reasonable expenses for
supporting this vital national infrastructure. For example, a small owner or
operator of the Bulk-Power System must bear the cost of complying with each
Reliability Standard that applies to it.
The proposed regional Reliability Standard was neither developed nor adopted
solely to protect against the imposition of reasonable expenses. The drafting team
considered and evaluated the effect of the changes in the curtailment process on the
distribution of costs among applicable entities and determined that the change provided in
the proposed regional Reliability Standard results in no cost-shift since the curtailment
amounts are the same as the existing IRO-STD-006-0 regional Reliability Standard.
There was no special accommodation made for smaller entities in the proposed standard.
Importantly, the proposed methodology increases the certainty of curtailments and
reliability enforcement thereby enhancing reliable operations relative to the current
approved version of the regional Reliability Standard, IRO-STD-006-0. Furthermore, the
proposed standard will apply equally to all applicable entities in a consistent manner.
The record of development in Exhibit C demonstrates that no stakeholder offered
comments pertaining to the cost impact of the standard relative to the size of the entity.
In addition and in particular, no small entity commented expressing a concern on cost to
implement.
10. Proposed Reliability Standards must be designed to apply throughout North
America to the maximum extent achievable with a single Reliability Standard
while not favoring one area or approach

Order No. 672 at P 331. A proposed Reliability Standard should be designed
to apply throughout the interconnected North American Bulk-Power System,
to the maximum extent this is achievable with a single Reliability Standard.
The proposed Reliability Standard should not be based on a single geographic
or regional model but should take into account geographic variations in grid
characteristics, terrain, weather, and other such factors; it should also take into

20

account regional variations in the organizational and corporate structures of
transmission owners and operators, variations in generation fuel type and
ownership patterns, and regional variations in market design if these affect the
proposed Reliability Standard.
The proposed regional Reliability Standard applies throughout the Western
Interconnection and does not favor one area or approach.
A Reliability Standard proposed by a Regional Entity must meet the same
standards that NERC’s Reliability Standards must meet, i.e., the regional Reliability
Standard must be shown to be just, reasonable, not unduly discriminatory or preferential,
and in the public interest.
The Commission’s Order No. 672 establishes two additional criteria that a
regional standard must satisfy. A regional difference from a continent-wide Reliability
Standard must either be:



More stringent than the continent-wide Reliability Standard (which includes a
regional standard that addresses matters that the continent-wide standard does
not), or
A regional Reliability Standard that is necessitated by a physical difference in
the bulk-power system.

The proposed standard satisfies the Commission’s criteria for approval of a
regional Reliability Standard. Specifically, the proposed IRO-006-WECC-1 standard is
more stringent than the NERC standard IRO-006-4 – Transmission Loading Relief
Standard. The NERC Reliability Standard IRO-006-4 – Transmission Loading Relief
requires a Reliability Coordinator experiencing a potential or actual SOL or
Interconnection Reliability Operating Limit (“IROL”) violations to take appropriate
actions to relieve transmission loading using local or interconnection-wide procedures
(Requirement R1). The proposed regional Reliability Standard goes beyond the NERC
Reliability Standard IRO-006-4 by establishing a process to reduce schedules that prevent

21

potential overloads during the next operating hour. IRO-006-WECC-1 Requirement R1
requires each Reliability Coordinator to approve or deny a request submitted by a
Transmission Operator of a Qualified Transfer Path (for Step 4 or higher as described in
“Attachment 1 WECC IRO-006-WECC-1 WECC Unscheduled Flow Mitigation
Summary of Actions”) within five minutes. Requirement R2 requires each Balancing
Authority to approve the curtailment requests to the schedules as submitted, implement
alternative actions, or a combination there of that collectively meets the Relief
Requirement.
11. Proposed Reliability Standards should cause no undue negative effect on
competition or restriction of the grid

Order No. 672 at P 332. As directed by section 215 of the FPA, the
Commission itself will give special attention to the effect of a proposed
Reliability Standard on competition. The ERO should attempt to develop a
proposed Reliability Standard that has no undue negative effect on
competition. Among other possible considerations, a proposed Reliability
Standard should not unreasonably restrict available transmission capability on
the Bulk-Power System beyond any restriction necessary for reliability and
should not limit use of the Bulk-Power System in an unduly preferential
manner. It should not create an undue advantage for one competitor over
another.
The proposed regional Reliability Standard does not restrict the available
transmission capability or limit use of the bulk power system in a preferential manner.
The proposed regional Reliability Standard includes a fair and reliable methodology for
curtailing Contributing Schedules through a fair and equitable process that includes
alternative curtailment options to meet the Relief Requirements.
12. The implementation time for the proposed Reliability Standards must be
reasonable.
Order No. 672 at P 333. In considering whether a proposed Reliability
Standard is just and reasonable, the Commission will consider also the

22

timetable for implementation of the new requirements, including how the
proposal balances any urgency in the need to implement it against the
reasonableness of the time allowed for those who must comply to develop the
necessary procedures, software, facilities, staffing or other relevant capability.
To facilitate implementation of compliance monitoring and reporting, the IRO006-WECC-1 drafting team identified refinements to the webSAS tool and the
curtailment procedure to implement the revised standard. Under the direction of the
WECC Unscheduled Flow Administrative Subcommittee and the drafting team,
refinements to allow TOPs to submit curtailment requests and permit the Reliability
Coordinators to actively and passively approve curtailment requests were implemented in
the webSAS program. However, since the proposed regional Reliability Standard is not
effective yet, the refinements have not been put into operation. Because the refinements
to webSAS have been completed, the drafting team believes that only a short time is
needed to implement the new IRO-006-WECC-1 standard. Therefore, WECC and NERC
request that the proposed regional Reliability Standard become effective on the first day
of the first quarter after regulatory approval.
13. The Reliability Standard development process must be open and fair
Order No. 672 at P 334. Further, in considering whether a proposed
Reliability Standard meets the legal standard of review, we will entertain
comments about whether the ERO implemented its Commission-approved
Reliability Standard development process for the development of the
particular proposed Reliability Standard in a proper manner, especially
whether the process was open and fair. However, we caution that we will not
be sympathetic to arguments by interested parties that choose, for whatever
reason, not to participate in the ERO’s Reliability Standard development
process if it is conducted in good faith in accordance with the procedures
approved by the Commission.
The proposed regional Reliability Standard was developed in accordance with the
Commission-approved Process for Developing and Approving WECC Standards, which

23

provides for a fair and open regional Reliability Standards development process.
Specifically, this process included drafting by an open and inclusive standards drafting
team; consideration of industry comments received during three WECC public posting
and comment periods; approval by the WECC Operating Committee; approval by the
WECC Board of Directors; WECC response to comments received by NERC as a result
of NERC public posting; WECC response to comments by FERC Staff; WECC response
to comments by NERC Staff; and production of other supporting documentation in
response to various public and staff questions or concerns.
14. Proposed Reliability Standards must balance with other vital public interests
Order No. 672 at P 335. Finally, we understand that at times development
of a proposed Reliability Standard may require that a particular reliability
goal must be balanced against other vital public interests, such as
environmental, social and other goals. We expect the ERO to explain any
such balancing in its application for approval of a proposed Reliability
Standard.
Neither NERC nor WECC believes there are any competing public interests with
respect to the request for approval of this proposed regional Reliability Standard. No
comments were received that indicated the proposed standard conflicts with other vital
public interests.
15. Proposed Reliability Standards must consider any other relevant factors
Order No. 672 at P 323. In considering whether a proposed Reliability
Standard is just and reasonable, we will consider the following general
factors, as well as other factors that are appropriate for the particular
Reliability Standard proposed.
***
Order No. 672 at P 337. In applying the legal standard to review of a proposed
Reliability Standard, the Commission will consider the general factors above.
The ERO should explain in its application for approval of a proposed

24

Reliability Standard how well the proposal meets these factors and explain
how the Reliability Standard balances conflicting factors, if any. The
Commission may consider any other factors it deems appropriate for
determining if the proposed Reliability Standard is just and reasonable, not
unduly discriminatory or preferential, and in the public interest. The ERO
applicant may, if it chooses, propose other such general factors in its ERO
application and may propose additional specific factors for consideration with
a particular proposed Reliability Standard.
NERC does not propose any additional factors for consideration at this time.

V.

SUMMARY OF THE RELIABILITY STANDARD DEVELOPMENT
PROCEEDINGS
a. Development History
In September 2007, WECC posted the initial draft of IRO-006-WECC-1 for

industry comment. The drafting team reviewed and responded to initial comments in
November 2007. During the first comment period, WECC received comments from six
entities. Of the six entities submitting comments, four indicated support for the proposed
regional Reliability Standard. One commenter provided suggested modifications to the
language of Requirement R1 and the Violation Severity Levels associated with
Requirement R1. The drafting team implemented changes to the proposed standard to
address these comments. One commenter suggested changes that the drafting team
believed duplicated language in an existing NERC continent-wide Reliability Standard,
and no changes were made as a result of this comment.
In November 2007, the drafting team posted a second draft of the proposed
standard for comment. During the second comment period WECC received comments
from two entities. Both commenters indicated support for the proposed regional
Reliability Standard, with one of the two commenters providing suggested additional

25

definitions or revisions to existing definitions in the proposed standard. The drafting
team made changes to clarify one of the definitions and responded to the remainder of the
suggested changes but made no additional changes.
In March, 2008, the WECC Operating Committee voted on IRO-006-WECC-1.
The standard received 73 votes in favor, two no votes and eight abstentions. In April,
2008 the WECC Board of Directors unanimously approved IRO-006-WECC-1.
Concurrent with WECC Board consideration of the proposed regional standard in
April, 2008 and as permitted by NERC’s Rules of Procedure, WECC submitted and
NERC posted IRO-006-WECC-1 for the required 45-day public posting that took place
from April 4, 2008 – May 20, 2008. During the NERC 45 day posting, no substantial
technical comments were made. WECC submitted the proposed regional Reliability
Standard to NERC in June, 2008 along with the drafting team’s Consideration of
Comments.
In accordance with NERC’s Rules of Procedure and the Regional Reliability
Standards Evaluation Procedure approved by the Regional Reliability Standards Working
Group, NERC provided its evaluation of the WECC proposed regional Reliability
Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief on July
30, 2008 and identified several concerns. NERC’s general observation was that the
proposed standard was significantly modified from that of the existing IRO-STD-006-0
standard. Specifically, NERC commented that the proposed standard no longer contains
requirements that are more stringent than the continent-wide NERC Reliability Standard
IRO-006-4 — Reliability Coordination — Transmission Loading Relief. This was the
main justification for consideration of IRO-006-WECC-1 as the regional standard.

26

WECC modified the existing standard such that the proposed standard, IRO-006WECC-1, only includes the curtailment portion of the Unscheduled Flow Mitigation
Plan. The existing approved standard IRO-STD-006-0 references WECC’s Unscheduled
Flow Mitigation Plan that contains directions to reduce flows that include phase-angle
regulators, series capacitors, and back-to-back DC lines before transaction curtailment.
These aspects made IRO-STD-006-0 more stringent than the NERC standard. The
impact of eliminating the technical requirements that specify when an operator is to
request a curtailment and the procedure for mitigating the overload is that the proposed
standard appeared to no longer meet the Commission criteria for a approving a regional
standard specified in Order No. 672. NERC staff presented this concern to the NERC
Board of Trustees at its October 29, 2008 meeting. The Board deferred action on the
proposed standard to permit NERC staff to further coordinate with WECC staff regarding
this concern.
NERC staff and WECC staff met several times thereafter to discuss the concern.
In November, 2008, WECC staff provided NERC with a set of documents further
explaining the proposed standard. WECC asserted that the companion regional standard,
TOP-007-WECC-1 - System Operating Limits addressed the concerns regarding the
obligation to act using the WECC Unscheduled Flow Mitigation Procedure. NERC staff
responded with a list of follow-up questions for further consideration by WECC in
December, 2008.
One of the two follow-up questions asked for clarification regarding the treatment
of certain paths (WECC Major Transfer Paths) within WECC. WECC uses TOP-007WECC-1 to manage the transfer path power flow on the Major WECC Transfer Paths

27

(using local and other relief procedures to ensure that power flows do not exceed SOL for
more than 30 minutes). Also, IRO-006-WECC-1 is used to ensure that Reliability
Coordinators are responding to curtailment requests by the Transmission Operators on six
of these transfer paths. However, NERC identified one path that is not included in the list
of Major Transfer Paths. This could mean that TOP-007-WECC-1 does not apply to this
path and as such the Transmission Operator is not actively monitoring power flows and
taking immediate action to relieve flow to not exceed its SOL.
In response to NERC’s concern, WECC clarified that there is not a gap in
reliability because the Transmission Operator is responsible for managing each transfer
path’s power flow. If a Transmission Operator requests the curtailment of off-path
schedules, Requirement R1 of IRO-006-WECC-1 requires the Reliability Coordinator to
approve or deny the request. The Reliability Coordinator’s opportunity to deny the
request is intended to prevent off-path schedule curtailments from causing other
reliability problems of which the Transmission Operator may not be aware. Further, flow
across the specific “missing” path in question is not significantly impacted by
unscheduled flow under normal system conditions, but only when a specific generating
unit is out of service. During instances when this generator is out of service, this specific
path then becomes a subset of a path that is included in the list of Major Transfer Paths.
Therefore, this specific path is not identified explicitly as one of the 40 major paths in
TOP-007-WECC-1.
The second NERC question requested clarification on the role the Reliability
Coordinator has in initiating curtailments. In the proposed standard, IRO-006-WECC-1,
the Reliability Coordinator is only obligated to respond to a Transmission Operator’s

28

curtailment request; however, there is no mention in either the proposed standard IRO006-WECC-1 or TOP-007-WECC-1 that the entity with the wide area view, the
Reliability Coordinator, can initiate curtailment requests if needed for reliability. Finally,
neither standard indicates what recourse the Transmission Operator has within WECC if
the Reliability Coordinator denies the request for curtailment. WECC confirmed that the
Reliability Coordinator does not actually initiate the curtailments, but rather, approves the
Transmission Operator’s request for curtailment(s). When a Transmission Operator
submits a request to the Reliability Coordinator for off-path schedule curtailments as
specified in the Unscheduled Flow Mitigation Plan, the Transmission Operator submits
those requests to the Reliability Coordinator through the OATI webSAS tool.
Requirement R1 of IRO-006-WECC-1 requires the Reliability Coordinator to approve or
deny the request using the webSAS tool. Unless the Reliability Coordinator denies the
request for reliability reasons, the webSAS tool, through preprogrammed algorithms,
identifies the off-path schedules to curtail and submits those curtailments to Balancing
Authorities, Purchasing Selling Entities, Generator Operators and Transmission
Operators identified on the tags.
WECC also confirmed that the Reliability Coordinator has the wide-area view,
not the Transmission Operator. Transmission Operators are responsible for managing
each transfer path’s power flow and have several options according to WECC’s
procedures. When a Transmission Operator requests the curtailment of off-path
schedules, the Reliability Coordinator may deny the request for reliability reasons. If the
Reliability Coordinator denies a curtailment request, the Transmission Operator in
coordination with the Reliability Coordinator would then follow one of the other WECC

29

or local procedures for reducing path flow. With respect to the broader concern that the
proposed standard was modified such that it only contains the curtailment portion of the
Unscheduled Flow Mitigation Plan, WECC explained that it is not necessary to reference
the remainder of the Unscheduled Flow Mitigation Plan because the remaining items
contain procedural requirements explaining “how,” not “what.” The proposed IRO-006WECC-1 standard includes requirements to reduce schedules, which then require
adjustments to generation patterns. This prevents potential overloads during the next
operating hour. Importantly, the requirements for mitigation of an actual (real-time)
overload are contained in TOP-007-WECC-1 — System Operating Limits. This
requirement, along with the requirements identified in the proposed IRO-006-WECC-1,
ensures that the TOP will utilize the phase-angle regulators, series capacitors, and backto-back DC lines before transaction curtailment.
In the process of discussing the concerns in the NERC evaluation, WECC and
NERC identified a shortcoming in the existing continent wide standard, IRO-006-4 –
Transmission Loading Relief. Historically, the NERC continent-wide standard, IRO006-3, at one point stood alone as the only standard, continent-wide or regional, to
address the procedure to be used in WECC for Unscheduled Flow Mitigation. This was
accomplished in Requirements R2 and R2.2 that state:
R2: A Reliability Coordinator experiencing a potential or actual SOL or IROL
violation within its Reliability Coordinator Area, shall, at its discretion, select
from either a “local” (Regional, Interregional, or subregional) transmission
loading relief procedure or an Interconnection-wide procedure.
R2.2. The equivalent Interconnection-wide transmission loading relief procedure
for use in the Western Interconnection is the “WSCC Unscheduled Flow
Mitigation Plan,” provided at
http://www.wecc.biz/documents/library/UFAS/UFAS_mitigation_plan_rev_2001clean_8-8-03.pdf.

30

In June 2007, FERC approved WECC regional standard IRO-STD-006-0 to
supplement the NERC continent-wide standard. Later in 2007, the NERC Board of
Trustees approved Version 4 of the IRO-006 continent-wide standard. While the
language in the main requirement, now labeled Requirement R1, is intended to be the
same as in the version 3 of the standard stated above, the sub-requirement pertaining to
WECC was modified to state the following:
R1.2 The Interconnection-wide transmission loading relief procedure for use in
the Western Interconnection is WECC-IRO-STD-006-0 provided at
http://www.nerc.com/docs/standards/rrs/IRO-STD-006-0_17Jan07.pdf.

Because the original version of the WECC regional standard (IRO-STD-006-1)
now referenced in the continent-wide standard also referred to the WECC Unscheduled
Flow Mitigation Plan, there was no concern with the reference change in the continentwide standard. However, the current proposed WECC regional standard, IRO-006WECC-1, no longer references the Mitigation Plan nor contains the details that the
original version of the regional standard contained. The result is a situation where the
combination of NERC continent-wide standard IRO-006-4 and proposed WECC regional
standard IRO-006-WECC-1 no longer includes the Unscheduled Flow Mitigation Plan
reference or the implementation details it once contained. As a result, WECC requested,
and NERC agreed, to reference the Unscheduled Flow Mitigation Plan in its continentwide IRO-006-4 standard, Requirement R1.2. At its January 2009 meeting, the Standards
Committee agreed to process the incorrect reference as an errata change. Once corrected,
the continent-wide standard will properly reference the incorporated WECC mitigation
procedure. NERC will be filing this errata change with the Commission in the next few
weeks.

31

In addition to the technical concerns discussed above, the NERC evaluation
revealed that the proposed standard includes a defined term for TDF that conflicts with
the NERC defined term in the NERC Glossary of Terms. WECC acknowledged this
inconsistency in the response to NERC’s comments. WECC and NERC agreed to
address the inconsistency in defined terms by proposing a modification to the applicable
continent-wide NERC defined term using the standards development process with the
intent that the modified definition would be technically sufficient for use across North
America. The NERC definition for TDF is therefore not technically applicable to the
Western Interconnection because it refers to “Flowgates,” a term not used in the Western
Interconnection. In addition, the NERC defined term specifies that the Interchange
Transaction portion is typically expressed per unit and flows across a transmission
facility (Flowgate). This does not apply to the Western Interconnection but rather is
expressed in a percentage flow across a transmission facility. WECC proposes that with
minor modifications to the NERC defined term, the inconsistency will be addressed and
the duplicative term will be withdrawn. This issue is pending before the TLR standard
drafting team.
Finally, NERC identified during its evaluation that, while the proposed standard
contains clear Violation Severity Levels, these compliance elements should be in a
consistent format with the continent-wide standards. WECC also acknowledged this
inconsistency and agreed to address it during the next revision of the standard after
regulatory approval.
As a result of the additional clarification provided by WECC during the
evaluation period, the IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow

32

Relief regional Reliability Standard was approved by the NERC Board of Trustees on
February 10, 2009. Exhibit B of this filing contains the NERC Board of Trustees’
Resolution on the WECC Regional Reliability Standard.
b. Key Issues
Commission Directives
The Commission approved IRO-STD-006-0 – Qualified Path Unscheduled Flow
Relief regional Reliability Standard in its June 8 Order. In the June 8 Order, the
Commission directed WECC to develop several specific modifications to the regional
Reliability Standard when WECC develops, through its Reliability Standards
development process, permanent, replacement Reliability Standards. These
modifications included:
-

Remove the sanctions table that is inconsistent with the NERC Sanctions
Guidelines and add Violation Risk Factors and Violation Severity Levels;
Clarify the term “receiver” and the applicability of the standard;
Consider industry comments that LSEs may not be able to meet the
requirements of the regional Reliability Standard (IRO-STD-006-0);
Conform the standard to the NERC Reliability Standards format,
specifically the effective date; and
Align the definition of “disturbance” with the NERC definition.

The Commission also directed WECC to meet its commitment to address the
shortcomings identified during the NERC review of the standard including the formatting
concerns.
The proposed regional Reliability Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow (USF) Relief addresses the FERC directives. In
developing a replacement standard WECC:
-

Removed the sanctions table and added Violation Risk Factors and
Violation Severity Levels;

33

-

-

-

Removed the term “receiver” in the applicability section of the proposed
standard and assigned the applicability to Reliability Coordinators and
Balancing Authorities;
Considered the industry comments regarding LSE’s and modified the
applicability section of the proposed standard and assigned the
applicability to Reliability Coordinators and Balancing Authorities;
Conformed the proposed standard to the NERC Reliability Standards
format including the effective date; and
Removed the proposed definition for “disturbance”.

In removing the definition for “disturbance” WECC noted that the differences in
the definitions are not significant to the interpretation of the standard.
Key Issues during Standard Development
The drafting team identified and addressed one key issue during the development
of the proposed IRO-006-WECC-1 regional Reliability Standard. In its June 8 Order, the
Commission directed WECC, among other things, to consider industry comments that the
LSEs may not be able to meet the requirements of the existing regional Reliability
Standard IRO-STD-006-0. This was the only key issue that had been identified by
commenters during the initial translation of the WECC Reliability Management System
(“RMS”) requirements to regional Reliability Standards when the initial interim Tier 1
Standards were developed. To address this concern and the FERC directive, the drafting
team modified the requirements of the standard to be applicable to the Reliability
Coordinator and Balancing Authority. As evidenced by the vote of the industry at the
WECC Operating Committee (“WECC OC”) meeting and the unanimous approval of the
regional Reliability Standard by the WECC Board of Directors, this change addressed the
industries concerns with the original standard.

34

Exhibit C of this filing contains the record of development of the proposed
Reliability Standard, including the minority opinions expressed from the WECC OC vote
received before the WECC Board of Directors balloted IRO-006-WECC-1.

VI.

CONCLUSION
NERC requests that the Commission approve the regional Reliability

Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief and the
related definitions to replace regional Reliability Standard IRO-STD-006-0. The
reliability of the bulk power system of the Western Interconnection is best served by the
implementation of this proposed regional Reliability Standard. In the interest of
improved reliability, NERC staff recommends Commission approval of the proposed
regional standard.

Respectfully submitted,

Rick Sergel
President and Chief Executive Officer
David N. Cook
Vice President and General Counsel
North American Electric Reliability Corporation
116-390 Village Boulevard
Princeton, NJ 08540-5721
(609) 452-8060
(609) 452-9550 – facsimile
[email protected]

35

/s/ Holly A. Hawkins
Rebecca J. Michael
Assistant General Counsel
Holly A. Hawkins
Attorney
North American Electric Reliability
Corporation
1120 G Street, N.W.
Suite 990
Washington, D.C. 20005-3801
(202) 393-3998
(202) 393-3955 – facsimile
[email protected]
[email protected]

CERTIFICATE OF SERVICE
I hereby certify that I have served a copy of the foregoing document upon all
parties listed on the official service list compiled by the Secretary in this proceeding.
Dated at Washington, D.C. this 17th day of June, 2009.
/s/ Holly A. Hawkins
Holly A. Hawkins
Attorney for North American Electric
Reliability Corporation

Exhibit A
Reliability Standard Proposed for Approval

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
Standard Development Roadmap
This section is maintained by the drafting team during the development of the standard
and will be removed when the standard becomes effective.
Development Steps Completed:
Completed Actions

6. Operating Committee approved proposed standard

Completion
Date
September 21,
2007
November 30,
2007
November 30,
2007
January 17,
2008
January 17,
2008
March 6, 2008

7. Post Draft Standard for WECC Board approval

March 12, 2008

8. Post Draft Standard for NERC comment period

April 14, 2008

9. WECC Board approved proposed standard

April 16, 2008

10. NERC comment period ends

May 20, 2008

11. Drafting Team to review and respond to industry comments

May 31, 2008

1. Post Draft Standard for initial industry comments
2. Drafting Team to review and respond to initial industry comments
3. Post Draft Standard for industry comments
4. Drafting Team to review and respond to industry comments
5. Post Draft Standard for Operating Committee approval

Description of Current Draft:
The purpose of this standard is to create a permanent replacement standard for IRO-STD006-0. IRO-006-WECC-1 is designed to implement the directives of FERC and
recommendations of NERC when IRO-STD-006-0 was approved as a NERC reliability
standard.
This version of the IRO-006-WECC-1 standard is for NERC Board of Trustee ballot.
The WECC Board of Directors approved the standard April 16, 2008. WECC Operating
Committee approved the standard March 6, 2008. The WECC Board of Directors and
Operating Committee request that the NERC Board of Trustees approve the IRO-006WECC-1 Standard as a permanent replacement standard for IRO-STD-006-0 and that the
NERC Board of Trustees submits the standard to FERC for approval and replacement of
IRO-STD-006-0.

Page 1 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
Future Development Plan:
Anticipated Actions
1. NERC Board approval request

Anticipated
Date
June 2008

2. Request FERC approval

June 2008

Page 2 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
Definitions of Terms Used in Standard

This section includes all newly defined or revised terms used in the proposed standard.
Terms already defined in the Reliability Standards Glossary of Terms are not repeated
here. New or revised definitions listed below become approved when the proposed
standard is approved. When the standard becomes effective, these definitions will be
removed from the standard and added to the Glossary.
DEFINITIONS:
Contributing Schedule is defined as a Schedule not on the Qualified Transfer Path between a
Source Balancing Authority and a Sink Balancing Authority that contributes unscheduled flow
across the Qualified Transfer Path.
Qualified Transfer Path: A transfer path designated by the WECC Operating Committee as
being qualified for WECC unscheduled flow mitigation.
Qualified Controllable Device: A controllable device installed in the Interconnection for
controlling energy flow, and the WECC Operating Committee has approved using the device for
controlling the USF on the Qualified Transfer Paths.
Qualified Transfer Path Curtailment Event: Each hour that a Transmission Operator calls for
Step 4 or higher for one or more consecutive hours (see Attachment 1-IRO-006-WECC-1) during
which the curtailment tool is functional.
Transfer Distribution Factor (TDF): The percentage of USF that flows across a Qualified
Transfer Path when an Interchange Transaction (Contributing Schedule) is implemented. [See
the WECC Unscheduled Flow Mitigation Summary of Actions Table (Attachment 1 WECC IRO006-WECC-1).]
Relief Requirement: The expected amount of the unscheduled flow reduction on the Qualified
Transfer Path that would result by curtailing each Sink Balancing Authority’s Contributing
Schedules by the percentages listed in the columns of WECC Unscheduled Flow Mitigation
Summary of Actions Table in Attachment 1 WECC IRO-006-WECC-1.

Page 3 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
A. Introduction
1.

Title:

Qualified Transfer Path Unscheduled Flow (USF) Relief

2.

Number:

IRO-006-WECC-1

3.

Purpose:
Mitigation of transmission overloads due to unscheduled flow on
Qualified Transfer Paths.

4.

Applicability

5.

4.1.

Balancing Authorities

4.2

Reliability Coordinators

Effective Date: The first day of the first quarter after applicable regulatory approvals.

B. Requirements
R.1. Upon receiving a request of Step 4 or greater (see Attachment 1-IRO-006-WECC-1)
from the Transmission Operator of a Qualified Transfer Path, the Reliability
Coordinator shall approve (actively or passively) or deny that request within five
minutes. [Violation Risk Factor: Medium] [Time Horizon: Real-time Operations]
R.2. The Balancing Authorities shall approve curtailment requests to the schedules as
submitted, implement alternative actions, or a combination there of that collectively
meets the Relief Requirement. [Violation Risk Factor: Medium] [Time Horizon: Realtime Operations]
C. Measures
M1. The Reliability Coordinator shall have evidence that it approved or denied the

request within five minutes in accordance with R1.
M2. The Balancing Authorities shall have evidence that they provided the Relief

Requirement through Contributing Schedules curtailments, alternative actions,
or a combination that collectively meets the Relief Requirement as directed in
R.2.
D. Compliance
1. Compliance Monitoring Process
1.1 Compliance Monitoring Responsibility

Compliance Enforcement Authority
1.2. Compliance Monitoring Period and Reset
Compliance Enforcement Authority may use one or more of the following methods to
assess compliance:

Page 4 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
-

Reviews conducted monthly
Spot check audits conducted anytime with 30 days notice given to prepare
Periodic audit as scheduled by the Compliance Enforcement Authority
Investigations
Other methods as provided for in the Compliance Monitoring Enforcement Program

1.2.1

Compliance Monitoring Period: A Qualified Transfer Path Curtailment Event

1.2.2

The Performance-reset Period is one calendar month.

1.3. Data Retention
Reliability Coordinators and Balancing Authorities shall keep evidence for Measure M.1
through M2 for three years plus current, or since the last audit, whichever is longer.
1.4. Additional Compliance Information
Compliance shall be determined by a single event, per path, per calendar month (at a
minimum) provided at least one event occurs in that month.
2. Violation Severity Levels of Non-Compliance for Requirement R1
2.1.

Lower: There shall be a Lower Level of non-compliance if there is one instance
during a calendar month in which the Reliability Coordinator approved (actively or
passively) or denied a Step 4 or greater request greater than five minutes after
receipt of notification from the Transmission Operator of a Qualified Transfer Path.

2.2.

Moderate: Not Applicable

2.3.

High: Not Applicable

2.4.

Severe: Not Applicable

3. Violation Severity Levels of Non-Compliance for Requirement R2
3.1.
Lower: There shall be a Lower Level of non-compliance if there is less than 100%
Relief Requirement provided but greater than or equal to 90% Relief Requirement
provided or the Relief Requirement was less than 5 MW and was not provided.

3.2.

Moderate: There shall be a Moderate Level of non-compliance if there is less than
90% Relief Requirement provided but greater than or equal to 75% Relief
Requirement provided and the Relief Requirement was greater than 5 MW and was
not provided.

3.3.

High: There shall be a High Level of non-compliance if there is less than 75% Relief
Requirement provided but greater than or equal to 60% Relief Requirement provided
and the Relief Requirement was greater than 5 MW and was not provided.

3.4.

Severe: There shall be a Severe Level of non-compliance if there is less than 60%
Relief Requirement provided and the Relief Requirement was greater than 5 MW
and was not provided.

Page 5 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
Version History – Shows Approval History and Summary of Changes in the Action Field
Version Date
Action
Change Tracking
1
April 16, 2008
Permanent Replacement Standard for IROSTD-006-0

Page 6 of 7

WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled
Flow Relief
Attachment 1 WECC IRO-006-WECC-1
WECC UNSCHEDULED FLOW MITIGATION
SUMMARY OF ACTIONS
Unscheduled Flow
Accommodation across Path

Step

Action Description

Equivalent Percent Curtailment Required in
Contributing Schedule -Based on amount of
Unscheduled Flow across the Qualified
Transfer Path
(Transfer Distribution Factor)
10-14%

15-19%

20-29%

30-49%

50+ %

10%

20%

1

Operate controllable
devices in path

NA

2

Accommodation

50 MW or 5% of maximum
transfer limit

3

Coordinated operation of
Qualified Controllable
Devices

50 MW or /5% of maximum
transfer limit

4

First level curtailment

50 MW or 5% of maximum
transfer limit

5

Second level curtailment

50 MW or 5% of maximum
transfer limit

10%

15%

25%

6

Accommodation

75 MW or 6% of maximum
transfer limit

10%

15%

25%

7

Third level curtailment

75 MW or 6% of maximum
transfer limit

10%

15%

20%

30%

8

Accommodation

100 MW or 7% of maximum
transfer limit

10%

15%

20%

30%

9

Fourth level curtailment

100 MW or 7% of maximum
transfer limit

15%

20%

25%

35%

Page 7 of 7

10%

Exhibit B
The NERC Board of Trustees’ Resolution on the
WECC Regional Reliability Standard

Resolution of the
NERC Board of Trustees
October 29, 2008
The Westin Arlington Gateway
801 North Glebe Road
Arlington, Virginia

WECC Tier 1 Reliability Standards

RESOLVED, that the North American Electric Reliability Corporation Board of Trustees
approves the following proposed Regional Reliability Standards developed by the
Western Electricity Coordinating Council (WECC), on condition that WECC address the
shortcomings raised during the comment periods in the next revision of the standards:
FAC-501-WECC-1 — Transmission Maintenance
PRC-004-WECC-1— Protection System and Remedial Action Scheme
Misoperation
TOP-007-WECC-1 — System Operating Limits
VAR-002-WECC-1 — Automatic Voltage Regulators
VAR-501-WECC-1 — Power System Stabilizer
In addition, the Board approves proposed standard BAL-002-WECC-1 — Contingency
Reserves.
The Board also defers action on proposed standard IRO-006-WECC-1 — Qualified Transfer
Path Unscheduled Flow (USF) Relief, pending receipt of additional information.

116-390 Village Blvd.
Princeton, NJ 08540
609.452.8060 | www.nerc.com

Exhibit C
Record of Development of Proposed WECC
Regional Reliability Standard

The Unscheduled Flow Drafting Team’s Reply to Comments Received During the First
Posting of IRO-006-WECC-1 (Comments were due November 5, 2007)
November 30, 2007
For the reasons given in the White Paper, Chelan County PUD supports the changes to
UFAS contained in the new standard.
If adopted, will BA's need to subscribe to and monitor the WebSAS tool?
Hugh Owen
Reply: The USF Drafting Team thanks you for your support. The Reliability Coordinator
(RC) will communicate the curtailment information to you via your tagging system.
Subscription to WebSAS may be needed to implement alternate actions pursuant to the
Unscheduled Flow Mitigation Plan and communicate that information to the RCs and
WECC. Path Operators will need to subscribe to WebSAS to call for relief.

Bonneville Power supports this Standard.
It is a constant challenge to keep LSE scheduling staff up to date on an issue they may
only see once a year during their shift. In addition, our Power Scheduling (PSE/LSE)
staff are not trained on the Western grid to help resolve reliability issues in other control
areas. We have just experienced 4 possible violations due to the tool not working
properly. Additional communication from WECC and OATI as well as extensive
training on our end may have helped avoid this situation, but I believe the reliability of
the system should not be in the hands of LSE's.
In addition, having an LSE do a Reliability curtailment has become a large issue when it
comes to liquidated damages.
Thanks to the Drafting Team for helping to address and resolve issues around
Unscheduled Flow.
Brenda Anderson
Reply: The USF Drafting Team thanks you for your support.
WECC Reliability Coordination Comments Work Group (RCCWG) Comments
RCCWG Members Commenting on this draft standard:
Nancy Bellows, WACM
Terry Baker, PRPA
Paul Bleuss, CMRC
Jeremy Brownrigg, RDRC
Mike Gentry, SRP
Robert Johnson, PSC

1

Greg Tillitson
WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief
The WECC RCCWG has understood from interaction from the WECC Standard IRO006-WECC-1 Standard Drafting Team that the standard drafting team believed that the
WECC Reliability Coordinators should participate in the process of initiating the
curtailment of Contributing Schedules to reduce flow in accordance with Attachment 1IRO-006-WECC-1 for the purpose of verifying that the curtailment request was valid.
WECC RCCWG members were told that once a Transmission Operator of a Qualified
Transfer Path requested a curtailment, the curtailment would automatically occur in 5
minutes if the WECC Reliability Coordinator did not cancel the Transmission Operator
notification.
With this in mind, the measures and violation severity levels of non-compliance for
Requirement R1 all point to time required past the allowed five minutes for initiation of
curtailment of contributing schedules by the WECC Reliability Coordinator. All of these
seem inconsistent with the knowledge that the curtailment is an automated process. The
WECC RCCWG suggests that the standard drafting team consider using a measure and
violation severity levels associated with a WECC Reliability Coordinator cancellation of
curtailment.
WECC RCCWG
Nancy Bellows
Reply: The drafting team made refinements to R1 and the severity level associated with
R1 to address the RCCWG’s concerns. Also, in Measurement M1, the drafting team
clarified the cancellation of a curtailment is not a violation.

The following comments refer to the White Paper.
The standard states that LSE’s may have the option of selecting which schedules to
curtail for compliance. Ultimately, it is the Balancing Authorities that are responsible for
USF mitigation. Therefore, Balancing Authorities should have the same privileges that
LSE’s have when it comes to selecting which schedules to curtail.
Requirement 2 states: "Once the Source and Sink Balancing Authorities receive
Curtailment requests through their tagging systems, the Balancing Authorities must
actively approve the curtailment request: implement alternative actions that provide the
Relief Requirement; or a combination thereof that collectively meets the Relief
Requirement.” Alternative actions could include a counter schedule that would cause
generation redispatch in a different Balancing Authorities control area. Thereby
achieving compliance without actively approving the curtailment request. Based on this,
SRP would like to recommend changing the wording in the highlighted sentence to; The
Balancing Authorities must approve or deny all USF curtailment requests. This would

2

line up with the wording in Measure 2.
Heinz Ontiveros
Salt River Project
Reply: Implementing this comment would restate INT-006-2 R1. The drafting team does
not believe it is appropriate to restate a NERC requirement. Requirement 2’s intent is for
the Balancing Authority to provide relief. Denial of a curtailment will not necessarily
provide relief.

PPL Montana & PPL EnergyPlus support the proposed Standard as currently drafted.
The proposed Standard properly applies decisions and subsequent actions regarding USF
to those entities (RCs & BAs) responsible for bulk electric system reliability and removes
applicability from marketing entities, such as LSEs and PSEs. Thus, the proposed
Standard now aligns with the NERC Functional Model and addresses concerns as
directed by the FERC.
PPLM & EPLU appreciate this opportunity to comment and the efforts of the UFAS
Standard Drafting Team on this proposed Standard.
Jon Williamson
PPL EnergyPlus
Reply: The USF Drafting Team thanks you for your support.

These comments were posted by WECC staff on behalf of Denise Koehn of Bonneville
Power Administration.
BPA is OK with this standard as written.
Reply: The USF Drafting Team thanks you for your support.

3

Consideration of Comments for IRO-006-WECC-1 – Unscheduled Flow
Comments were due January 2, 2008
January 14, 2008
The IRO-006-WECC-1 Standard Drafting Team thanks all commenters who submitted
comments on the WECC IRO-006-WECC-1 Standard. This Standard was posted for a
30-day public comment period from November 30, 2007 through January 2, 2008. The
Standard Drafting Team asked stakeholders to provide feedback on the standard by
posting comments on the WECC website. There were two sets of comments from two
companies.
In this ‘Consideration of Comments’ document, stakeholder comments have been
organized so that it is easier to see the responses associated with each comment.
If you feel that your comment has been overlooked, please let us know immediately. Our
goal is to give every comment serious consideration in this process! If you feel there has
been an error or omission, you may contact the Director of Standards, Steve Rueckert at
801-582-0353 or at [email protected]. In addition, there is a WECC Appeals Process.
Comments and Responses
Bonneville Power Administration supports this Standard.
It is a constant challenge to keep LSE scheduling staff up to date on an issue they may
only see once a year during their shift. In addition, our staff is not trained on the Western
grid to help resolve reliability issues in others control area.
We have just experienced 4 possible violations due to the tool not working properly.
Additional communication from WECC and OATI as well as extensive training on our
end may have helped avoid this situation, but I believe the reliability of the system should
not be in the hands of LSE's.
In addition, having an LSE do a Reliability curtailment has become a large issue when it
comes to liquidated damages.
Brenda Anderson
Reply: Thank you for your support.

2-Jan-08
The standards’ drafting team has taken a very complex subject and made it into
something very usable. The following are comments and suggestions by PPL Energy
Plus, LLC (“EPLUW”).

1

Definitions EPLUW would like to see changed or added to:
• Contributing Schedule: Would it be more accurate to clarify that schedules are between
zones within BA’s rather than just between BA’s?
Reply: The definition does not specify that the two Balancing Authorities have to be
different. The Source Balancing Authority and Sink Balancing Authority may be the
same Balancing Authority on the tag. Therefore, no change is required to the definition.
• TDF: Include a sentence stating a POS TDF loads the qualified path and a NEG TDF
unloads the qualified path. This helps everyone understand the very important TDF sign
relationship.
Reply: The definition for positive and negative TDFs is a training issue and should be
covered in a training document not the standard. Therefore, the drafting team did not
make the requested modification.
• Relief Required:
o The definition is written as if schedule curtailments were the only way to provide relief,
when in reality, other actions taken by the sink BA can provide relief. Could the phrase
“…result by curtailing each Sink Balancing Authority’s Contributing Schedules by…” be
replaced with “result by actions of the Sink BA including but not limited to curtailing
contributing schedules…”?
Reply: The definition only defines how you calculate the required relief, not how to
comply with the requirement. Use of alternative actions to provide the required relief is
covered under R2. Therefore, the drafting team did not modify the definition.
o EPLUW would also like to see wording in the definition of Relief Required that
requires the Sink BA (when using schedule curtailments to provide relief) to curtail the
most effective (i.e. highest POS TDF) schedules first.
Reply: The definition only defines how you calculate the required relief, not how to
comply with the requirement. If the drafting team implements this recommendation, it
would remove the choice for providing the required relief. The drafting team believes the
members want the ability to have a choice.
Possible definitions to include:
• A qualified Transfer Path Event should have a definition in the definitions section. The
standard attempts to define Transfer Path Event in section 1.2.1.
Reply: The drafting team moved the definition from 1.2.1 to the definition section. The
drafting team also clarified the definition.
The standard should clearly define what is Step 4 and the obligations related thereto and
any preceding steps.

2

Reply: Through inclusion of the table in Attachment 1 WECC IRO-006-WECC-1, the
definition of step 4 and all steps is captured.
Section D, Compliance
1.2 Monitoring - Please remove the section stating “Other methods as provided for in the
Compliance Monitoring Enforcement Program” from the standard because this program
could undergo changes that would not receive due process. Alternately, please list in the
standard the provisions in the Compliance Monitoring Program that will be used for this
standard.
Reply: The drafting team does not have authority over the compliance monitoring
program. The compliance enforcement authority retains the right to modify its program
as needed.
Section 1.2.2 – Please re-phrase this section to make it clear that the Compliance
Monitoring period starts anew each calendar month (if this indeed is the case).
Reply: The definition for a reset period means that the compliance monitoring period
begins again each month.
Section 2 – EPLUW believes Sections 2.2, 2.3, 2.4 are applicable and should be written
to prevent more than one instance of the RC missing the 5 minute time requirement. It
appears that as written, the standard provides no incentive for the RC to perform after the
first violation of the month.
Reply: This is one tool of several that reliability coordinator and transmission operators
can use to prevent violations of system operating limits. Transmission Operators are
primarily responsible for keeping actual flows to within limits. The drafting team
recognizes that inaction on behalf the reliability coordinator will not result in failure of
the unscheduled flow mitigation plan because the webSAS tool will implement the
curtailment. Therefore, the severity level is low.
EPLUW has no comments on the very clear white paper and thanks the standard drafting
team for their hard work.
Reply: Thank you.
John Cummings

3

Western Electricity Coordination Council
Operating Committee Meeting
March 6-7, 2008
Albuquerque, NM
Voting Results
1.

Motion:
The IRO-006-WECC-1 Standard Drafting Team recommends that the
OC approve IR0-006-WECC-1 and that after regulatory approval, it
shall supersede IRO-STD-006-0.
Explanation: Mitigation of transmission overloads due to unscheduled flow on
Qualified Transfer Paths.
VOTING CLASS
TRANSMISSION
PROVIDERS
TRANSMISSION
CUSTOMERS
STATE and
PROVINCIAL
TOTALS

YES
33

NO
0

ABSTAIN
1

39

2

7

1

0

0

73

2

8

Result: PASSED
Minority Opinion:
No minority opinions were offered at the meeting and none were received via
email.

1

APPENDIX A
REASONS FOR NO VOTES 1

John S. Forman, Transmission Agency of Northern California (TANC)
In response to the question of why a no vote was made on the standards at the OC
meeting, TANC's OC representative voted no on five of the seven proposed standards for
one basic reason: The standards require that the WECC be more stringent than the NERC
standards. Those entities that have gone through an audit of the standards that are in
effect are finding that they will be sited for something that is not in compliance. In other
words, the auditors will keep looking until something is found to be wrong. With the
WECC standards higher than NERC, even more compliance problems are anticipated.
We believe that one basic instruction to the drafting teams should be that they need to
justify a standard being more stringent than NERC, and that the basic draft should be no
more than equal to NERC, unless it's clearly in the interest of the WECC. Our two
positive votes on VAR-501 and IRO-006 are in that "best interest of WECC" category.
The other standards were not. Basically, we are not sure that always being better than
NERC is the right philosophy.
***********************************************************************

1

The reasons for no votes in the appendix were submitted by the individual entities via email after the
Operating Committee meeting. The reasons for no votes in the main document were stated at the Operating
Committee Meeting in Albuquerque, NM

2

Board of Directors
April 16-18, 2008
Coronado, CA

Voting Summary
IRO-006-WECC-1

Last Name

First NamOrganization

Class

Anderson
Areghini
Barbash
Beyer
Brown
Campbell
Cauchois
Chamberlain
Cleary
Conway
Coughlin
Dearing
Ferreira
Grantham-Richards
Gutting
Kelly
King
LaFond
Little
McMaster
Moya
Newton
Sharpless
Smith
Stout
Tarplee
Thuston
Weis
VanZandt
Zaozirny

Bob
David
Carolyn
Lee
Duncan
Ric
Scott
Bill
Anne
Teresa
John
Bill
Richard
Maude
Scott
Nancy
Jack
Steve
Doug
Dale
Jesus
Tim
Jananne
Marsha
John
Gary
Tim
Larry
Vicki
Lori Ann

Non-Affiliated
Class 1
Class 1
Class 5
Class 3
Class 5
Class 4
Class 5
Class 3
Class 6
Non-Affiliated
Class 2
Class 2
Class 2
Class 4
Class 4
Non-Affiliated
Class 4
Class 6
Class 6
Mexico
Non-Affiliated
Non-Affiliated
Class 5
Class 3
Class 1
Class 3
Class 2
Class 1
Class 6

Non-affiliated Director
Salt River Project
Sierra Pacific Power Company
California Public Utilities Commission
Calpine Corporation
Utah Public Service Commission
CADRA
California Energy Commission
Mirant Americas, Inc.
Powerex Corp.
Non-affiliated Board Member
Grant County PUD
TANC Executive Advisor
Farmington Electric Utility System
Energy Strategies, LLC
Utah Committee of Consumer Services
Non-affiliated Board Member
The Boeing Company
British Columbia Transmission Corporation
Alberta Electrical System Operator
Comision Federal de Electricidad
Non-affiliated Director
Non Affiliated Board Member
Idaho Public Utilities Commission
Mariner Consulting
Southern California Edison
Williams Power
Turlock Irrigation District
Bonneville Power Administration
British Columbia Utilities Commission

The Board Members listed above voted whether to approve IR0-006-WECC-1.
The Regional Reliability Standard was approved unanimiously.

Comment Report Form for WECC Standard IRO-006-WECC-1 – Qualified Transfer
Path Unscheduled Flow Relief

The IRO-006-WECC-1 Standard Drafting Team thanks all commenters who submitted
comments on the IRO-006-WECC-1 Standard. This Standard was posted for a 45-day
public comment period from April 4, 2008 through May 20, 2008. NERC distributed the
notice for this posting on April 7, 2008. The Standard Drafting Team asked stakeholders to
provide feedback on the standard through a special Standard Comment Form. There were
two sets of comments from four companies representing four of the ten Industry Segments
as shown in the table on the following pages.
In this ‘Consideration of Comments’ document stakeholder comments have been organized
so that it is easier to see the responses associated with each question. All comments
received on the Standard can be viewed in their original format at:
http://www.nerc.com/~filez/regional_standards/regional_reliability_standards_under_devel
opment.html
If you feel that your comment has been overlooked, please let us know immediately. Our
goal is to give every comment serious consideration in this process! If you feel there has
been an error or omission, you can contact the Manager of Regional Standards, Stephanie
Monzon at [email protected]. In addition, there is a NERC Reliability Standards
Appeals Process. 1

1

The appeals process is described in the NERC Regional Reliability Standards Development Procedure:
ftp://www.nerc.com/pub/sys/all_updl/sac/rrswg/NERC_Regional_Reliability_Standards_Development_P
rocedure_Version%200-0%202007-06-15_dwt.pdf
16-390 Village Boulevard, Princeton, New Jersey 08540-5721
Phone: 609.452.8060 ▪ Fax: 609.452.9550 ▪ www.nerc.com

Comment Report Form for WECC Standard IRO-006-WECC-1 – Qualified Transfer
Path Unscheduled Flow Relief
The Industry Segments are:
1 — Transmission Owners
2 — RTOs, ISOs
3 — Load-serving Entities
4 — Transmission-dependent Utilities
5 — Electric Generators
6 — Electricity Brokers, Aggregators, and Marketers
7 — Large Electricity End Users
8 — Small Electricity End Users
9 — Federal, State, Provincial Regulatory or other Government Entities
10 – Regional Reliability Organizations, Regional Entities

Commenter

Organization

Industry Segment
1

2

3

4

5

6

9

9

9

9

1.

Chuck Westbrook

Bonneville Power

2.

Annette Bannon

PPL Generation, LLC

3.

Jon Williamson

PPL EnergyPlus

9

4.

John Cummings

PPL EnergyPlus

9

5.

Tom Olson

PPL Montana, LLC

9

-2-

9

9

7

8

9

10

Comment Report Form for WECC Standard IRO-006-WECC-1 – Qualified Transfer
Path Unscheduled Flow Relief

Index to Questions, Comments, and Responses
1. Was the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path

Unscheduled Flow Relief developed in a fair and open process, using the
Process for Developing and Approving WECC Standards?
page 4

2. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path

Unscheduled Flow Relief pose an adverse impact to reliability or commerce in a
neighboring region or interconnection?
page 4

3. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path

Unscheduled Flow Relief pose a serious and substantial threat to public health,
safety, welfare, or national security?
page 4
4. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path

Unscheduled Flow Relief pose a serious and substantial burden on competitive
markets within the interconnection that is not necessary for reliability? page 5

5. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path

Unscheduled Flow Relief meet at least one of the following criteria? page 5

- The proposed standard has more specific criteria for the same
requirements covered in a continent-wide standard
- The proposed standard has requirements that are not included in
the corresponding continent-wide reliability standard
- The proposed regional difference is necessitated by a physical
difference in the bulk power system.

-3-

Comment Report Form for WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief
1. Was the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief developed in a fair and open

process, using the Process for Developing and Approving WECC Standards?
Summary Consideration:
Commenter

Chuck Westbrook

Yes
X

No

Comment

Response: Thank you.

Annette Bannon, Jon Williamson,
John Cummings, and Tom Olson

X

PPL supports this much needed update to the unscheduled flow standard.

Response: Thank you for your support.

2. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief pose an adverse impact to

reliability or commerce in a neighboring region or interconnection?

Summary Consideration:
Commenter

Yes

Chuck Westbrook

No
X

Comment

Response: Thank you.

Annette Bannon, Jon Williamson,
John Cummings, and Tom Olson
Response:
3. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief pose a serious and substantial

threat to public health, safety, welfare, or national security?

Summary Consideration:
Commenter

Chuck Westbrook

Yes

No
X

Comment

Response: Thank you.

Annette Bannon, Jon Williamson,
John Cummings, and Tom Olson

-4-

Comment Report Form for WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief
Commenter

Yes

No

Comment

Response:
4. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief pose a serious and substantial

burden on competitive markets within the interconnection that is not necessary for reliability?
Summary Consideration:
Commenter

Yes

Chuck Westbrook

No
X

Comment

Response: Thank you.

Annette Bannon, Jon Williamson,
John Cummings, and Tom Olson
Response:
5. Does the WECC Standard IRO-006-WECC-1 – Qualified Transfer Path Unscheduled Flow Relief meet at least one of the

following criteria?

- The proposed standard has more specific criteria for the same requirements covered in a continent-wide
standard
- The proposed standard has requirements that are not included in the corresponding continent-wide
reliability standard
- The proposed regional difference is necessitated by a physical difference in the bulk power system.
Summary Consideration:
Commenter

Chuck Westbrook

Yes
X

No

Comment

Response: Thank you.

Annette Bannon, Jon Williamson,
John Cummings, and Tom Olson
Response:

-5-

IRO-006-WECC-1 Comparison
This following document prepared by the drafting team during the development of the WECC Standard IRO-006-WECC-1 – Contingency
Reserve compares this proposed regional standard to the existing WECC IRO-STD-006-0.
The purpose of this document to provide documentation of each proposed change.

1

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief
A. Introduction
1. Title: Qualified Transfer Path Unscheduled Flow (USF)
Relief
2. Number: IRO-006-WECC-1

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief
1. Title: Transmission Maintenance
2. Number: IRO-STD-006-0

3. Purpose: Mitigation of transmission overloads due to
unscheduled flow on Qualified Transfer Paths.

3. Purpose: Mitigation of transmission overloads due to unscheduled
line flow on Qualified Paths.

4. Applicability

4) Applicability
4.1. This Standard is applicable to Transmission Owners or Operators
that maintain the transmission paths in Attachment A – WECC Table
2 and is applicable only to those facilities associated with each of the
paths identified.

4.1 Balancing Authorities

4.2
Reliability Coordinators
5. Effective Date: On the first day of the next quarter, after
receipt of applicable regulatory approval.

B. Requirements

Comment

5. Effective Date: This Western Electricity Coordinating Council
Regional Reliability Standard will be effective when approved by
the Federal Energy Regulatory Commission under Section 215 of
the Federal Power Act. This Regional Reliability Standard shall be
in effect for one year from the date of Commission approval or
until a North American Standard or a revised Western Electricity
Coordinating Council Regional Reliability Standard goes into
place, whichever occurs first. At no time shall this regional
Standard be enforced in addition to a similar North American
Standard.
B. Requirements

2

Title updated to
reflect revised
titling criteria
Updated to reflect
the overall purpose
of the proposed
revised standard.
Transmission
Owners is a defined
term in NERC’s
Functional Model,
so it is used in this
standard without
being redefined.

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief
R1.

R2.

Upon receiving a request of Step 4 or greater (see
Attachment 1-IRO-006-WECC-1) from the
Transmission Operator of a Qualified Transfer
Path, the Reliability Coordinator shall approve
(actively or passively) or deny that request within
five minutes. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]
The Balancing Authorities shall approve
curtailment requests to the schedules as submitted,
implement alternative actions, or a combination
there of that collectively meets the Relief
Requirement. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

WR1
Curtailment of Contributing Schedules

R.1 and WR1 are
intended to perform
the same function.

WECC's Unscheduled Flow Mitigation Plan (Plan), which is on file
with FERC and has been accepted by FERC (most recently prior to
the date hereof on November 20, 2001 in Docket No. ERO1-3085000), 1/ specifies that members 2/ shall comply with requests from
(Qualified) Transfer Path Operators to take actions that will reduce
unscheduled flow on the Qualified Path in accordance with the table
entitled "WECC Unscheduled Flow Procedure Summary of
Curtailment Actions," which is located in Attachment 1 of the Plan.

The drafting team
removed relay
maintenance from
Attachment 1
because NERC
protection system
reliability standards
exist.

Plan Section 11:
11.1 When USF Accommodation, as specified in Section 7,
together with coordinated operation of the Qualified
Controllable Devices, as specified in Section 9, are insufficient
to reduce the Actual Flow on the Qualified Transfer Path to
below the Transfer Limit, the Transfer Path Operator shall
request curtailments in Schedules that contribute to the USF
through the Qualified Transfer Path according to the USF
Reduction Procedure.
11.2 Responsible Entities shall comply in a timely manner with a
Transfer Path Operator's request for Schedule Curtailments
Plan Attachment 1 Section 9:
"h.
Upon receipt of a curtailment request, Contributing
Schedules which are subject to curtailments will be reduced (or

3

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief
equivalent alternative schedule adjustments will be effected) in
accordance with the following procedures:
i.
Receivers of Contributing Schedules will initiate the
requested schedule reductions unless an otherwise agreed upon
procedure for schedule reduction achieving the equivalent effect
on the Qualified Transfer Path is established by the Receiver
and/or the Sender.
ii.
Responsible Entities may arrange among themselves to
make curtailments called for by this USF Reduction Procedure in
a manner other than prescribed provided that the arrangements are
as effective as the identified schedule curtailment in reducing USF
across the Qualified Transfer Path. Responsible Entities may make
bilateral arrangements, which will enable a Responsible Entity
with schedules on the affected Qualified Transfer Path to make the
required curtailments in lieu of making larger curtailments in
schedules over other parallel paths. Where alternative schedule
adjustments are utilized, it is the Receiver's responsibility to cause
schedule adjustments to be effected which provide the same
reduction in flow across the Qualified Transfer Path as would have
been achieved by the prescribed reduction in the Contributing
Schedule.
iii.
The total amount of requested schedule reduction may
be apportioned to the applicable schedules at the discretion of
the Receiver subject to item iv below.
iv.
Irrespective of the schedules altered or the manner in which
they are altered, each Responsible Entity's overall net reduction in
Actual Flow across the constrained Qualified Transfer Path must
be equivalent to or greater than the reduction which would have

4

Comment

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief
been achieved had the identified schedule reduction occurred as
requested.
v.
System dispatchers or real-time schedulers should identify
in advance those schedules that qualify for curtailment requests
for all Qualified Transfer Paths. This will expedite
implementation of this USF Reduction Procedure when
requested.
vi.
While this USF Reduction Procedure does not expect
receivers to curtail schedules which would result in loss of
firm load, nothing in this USF Reduction Procedure shall
relieve the receiver of the obligation to achieve the required
reduction in USF across the constrained Qualified Transfer
Path."
Contributing Schedule curtailments apply to schedules in place
before initiation of the USF Procedure at Step 4 (First level
Contributing Schedule Curtailment) or higher step. At the time a
Step 4 Level 1 USF Action or higher step is initiated, Schedules are
established by the existence of an "Implemented" NERC Transaction
Tag.
Restricted Transactions
After the USF Event is declared, a transaction with greater
than a 5% Transfer Distribution Factor (TDF) on the
Qualified Path in the qualified direction will be considered a
"Restricted Transaction." Changes to Restricted Transactions,
other than the specific curtailments used to comply with relief
obligations, cannot be made unless some alternative action is

5

Comment

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

taken to compensate for the full impact on the Qualified Path.
This applies to: New transaction, and Extensions or
Adjustments to existing transaction."
If two or more Qualified Paths become simultaneously constrained
to the point where the curtailment of contributing schedules is
necessary, schedule curtailments which relieve USF on one path but
increase USF on any other curtailed path shall not be made, unless
specific procedures or methods are provided to address this
condition. The entity shall be compliant with this standard although
the required curtailments were not made.
C. Measures

C. Compliance Measures
M1.

M1. The Reliability Coordinator shall have
evidence that it approved or denied the request

within five minutes in accordance with R1.
M2. The Balancing Authorities shall have evidence

that they provided the Relief Requirement
through Contributing Schedules curtailments,
alternative actions, or a combination that
collectively meets the Relief Requirement as
directed in R.2.
D. Compliance
1 Compliance Monitoring Process
1.1
Compliance Monitoring Responsibility

Compliance Enforcement Authority

Responsible Entities shall take actions as requested by
Qualified Transfer Path Operators that result in the specified
amount of Unscheduled Flow Relief for the applicable
Qualified Transfer Path. These actions include, but are not
limited to, one or a combination of schedule curtailments,
schedule increases, and operation of non-Qualified Controllable
Devices.
It is the responsibility of each Responsible Entity to have in
place procedures for receipt of notification of a Qualified
Transfer Path Operators request. Failure to provide the
required USF relief or to increase USF shall not be excused
due to failure to receive notification.

D Compliance
1. Compliance Monitoring Process
1.1Compliance Monitoring Responsibility
Western Electricity Coordinating Council (WECC)

6

Measures were
simplified to
correspond with
each main
requirement.

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

1.2 Compliance Monitoring Period
Compliance Enforcement Authority may use one or more
of the following methods to assess compliance:

1.2

Remove specificity
for reporting. The
Compliance
Enforcement
Authority will
include this detail in
its reporting
instructions.

- Reviews conducted monthly
- Spot check audits conducted anytime with 30 days
notice given to prepare
- Periodic audit as scheduled by the Compliance
Enforcement Authority
- Investigations
- Other methods as provided for in the Compliance
Monitoring Enforcement Program
1.2.1

Compliance Monitoring Period: A Qualified
Transfer Path Curtailment Event

1.2.2

The Performance-reset Period is one calendar
month.

Compliance Monitoring Period At Occurrence and Yearly
The actions taken by Responsible Entities in response
to requests by the Qualified Transfer Path Operators
shall be documented and supplied to WECC Staff in
accordance with the Plan Section 9. The WECC Staff
will make specific requests for data submittal,
including the specification of dates, hours, and
required submittal dates.
Responsible Entities are to report the actions taken in
accordance with the Plan for each hour of a curtailment
period. Each Responsible Entity shall promptly provide
documentation, as requested by UFAS and/or WECC
Staff, of all such accommodation, control or curtailment
actions taken by its dispatchers, system operators or realtime schedulers. In addition, each Transfer Path
Operator shall provide documentation to the WECC staff
regarding actions taken or not taken in filling its
responsibilities during each curtailment period.
Responsible Entities' documentation shall use formats
and reporting conventions developed and monitored by
the WECC Operating Committee. Responsible Entities
may use the reporting applications as adopted by the
Unscheduled Flow Administrative Subcommittee
(UFAS) to submit curtailment data. On or before the
tenth Business Day following the date of a WECC Staff
USF letter request for data, each entity shall distribute to
the WECC Staff the USF information at the e-mail
addresses specified on the WECC web site. The USF
information shall include the identification of

7

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

Responsible Entities who failed to adjust schedules
according to this USF Reduction Procedure.

1.3 Data Retention Data Retention
Reliability Coordinators and Balancing Authorities
shall keep evidence for Measure M.1 through M2 for
three years plus current, or since the last audit,
whichever is longer.

1.4 Additional Compliance Information
Compliance shall be determined by a single event, per
path, per calendar month (at a minimum) provided at
least one event occurs in that month.

Each Responsible Entity identified in SectionA.4.1 shall submit the
completed USF Reduction Procedure Reporting output to the WECC
Staff by no later than 5:00 p.m. Mountain Time on the tenth Business
Day following the date of the WECC Staff USF letter. UFAS has
developed an Administrative Practice 007 "Curtailment Event
Selection Evaluation Process" that is utilized to select one event per
path per month for Compliance Evaluation. WECC Staff selects one
event during the first week following the month to review.
1.3
Data Retention Data will be retained in electronic form for at
least one year. The retention period will be evaluated before expiration
of one year to determine if a longer retention period is necessary. If
the data is being reviewed to address a question of compliance, the
data will be saved beyond the normal retention period until the
question is formally resolved.

1.4. Additional Compliance Information
For purposes of applying the sanctions for violations of this criterion,
the "Sanction Measure" is the greater of the maximum hourly
integrated MWH of "Required Relief" or "USF Increase" (truncated to
the nearest MW) during the specified period multiplied by 50, and the
"Specified Period" is the most recent calendar month. The sanctions
shall be assessed on a monthly basis, but for purposes of determining
the applicable column in the table in Sanction Table, all occurrences
within the specified period of the most recent calendar month and all
immediately preceding consecutive calendar months in which at least
one instance of non-compliance occurred shall be considered. For
example, if the maximum hourly integrated Required Relief was 25
MW and the maximum hourly integrated USF Increase for the period

8

Data retention
period lengthened
to 3 years plus the
current year to
ensure data are kept
in a contiguous
manner between
audit periods.
No longer needed
because the NERC
sanction table is
used.

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

2. Violation Severity Levels of Non-Compliance for
Requirement R1

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

was 30 MW, the Sanction Measure for the period would be 30 MW
times 50 or 1,500. If the maximum hourly integrated Required Relief
was 24 MW and the maximum hourly integrated USF Increase was 10
MW, the Sanction Measure for the period would be 24 times 50 or
1,200.
Levels of Non-Compliance Sanction
Sanction Measure: Normal Path Rating
For each separate USF Schedule Curtailment event (multiple
hours), the level of the noncompliance shall be based upon the
magnitude of MWh relief required and the ratio of actual MWh
relief provided to the required MWh of relief (truncated to the
nearest MWh) for every hour that the curtailment requirement was
in effect. The non-compliance levels are indicated in the table
below:

2.1. Lower: There shall be a Lower Level of noncompliance if there is one instance during a
calendar month in which the Reliability
Coordinator approved (actively or passively)
or denied a Step 4 or greater request greater
than five minutes after receipt of notification
from the Transmission Operator of a
Qualified Transfer Path.

For each separate USF Schedule Curtailment event (multiple
hours), the level of the noncompliance shall be based upon the
magnitude of MWh relief required and the ratio of actual MWh
relief provided to the required MWh of relief (truncated to the
nearest MWh) for every hour that the curtailment requirement
was in effect. The non-compliance levels are indicated in the
table below:
Ratio of actual MWh relieved to the required MWh of
relief (%) and magnitude of the required MWh of relief:.

Level of NonCompliance

2.2. Moderate: Not Applicable
2.3. High: Not Applicable
2.4. Severe: Not Applicable

100% > percent relief
required MWh of relief
not achieved.

9

90% or
5 and was

Level 1

Lower Severity
Levels defined for
each requirement.

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief
90% > percent relief
required MWh of relief > 5.

75% and

Comment

Level 2

75% > percent relief
60% and
required MWh of relief > 5.

Level 3

percent relief <60% and required
MWh of relief > 5.

Level 4

Failure to Report

Level 4

If an entity during an USF Schedule Curtailment event initiates a
Restricted Transaction that increases USF across the Qualified
Path requesting relief, without making an equal compensating
change to other transactions, the level of noncompliance shall be
determined in accordance with the table below.

For each hour the percent of
USF increases due to
0 % < USF increase 1 % of
1 % < USF increase 2 % of
2 % < USF increase 3 % of
USF increase > 3 % of the

Level of NonCompliance
Level 1
Level
Level
Level 4

For every hour that the curtailment requirement was in effect, the level
of non-compliance assessed to an entity shall be the higher level of
noncompliance determined under the percent relief and USF increase
tables shown above.
3. Violation Severity Levels of Non-Compliance for
Requirement R2
3.1.

Moderate Severity
Levels defined for
each requirement.

Lower: There shall be a Lower Level of noncompliance if there is less than 100% Relief

10

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

Requirement provided but greater than or equal to
90% Relief Requirement provided or the Relief
Requirement was less than 5 MW and was not
provided.

3.2.

Moderate: There shall be a Moderate Level of
non-compliance if there is less than 90% Relief
Requirement provided but greater than or equal to
75% Relief Requirement provided and the Relief
Requirement was greater than 5 MW and was not
provided.

3.3.

High: There shall be a High Level of noncompliance if there is less than 75% Relief
Requirement provided but greater than or equal to
60% Relief Requirement provided and the Relief
Requirement was greater than 5 MW and was not
provided.

3.4.

Severe: There shall be a Severe Level of noncompliance if there is less than 60% Relief
Requirement provided and the Relief
Requirement was greater than 5 MW and was
not provided.
High Severity
Levels defined for
each requirement.

2.3. High: There shall be a High Level of noncompliance if any of the following
condition exists:
2.3.1 The TMIP does not include associated
Facilities for three of the Paths identified
in the most current Table titled “Major
WECC Transfer Paths in the Bulk
Electric System” as required by R.1 and

11

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

Comment

Transmission Owners are not performing
maintenance and inspection for the
missing Facilities.
2.3.2 The TMIP does not include three
maintenance categories identified in
Attachment 1 FAC-501-WECC-1 as
required by R.2 but Transmission
Owners are performing maintenance and
inspection for the missing maintenance
categories.
2.3.3 Transmission Owners are not performing
maintenance and inspection for two
maintenance categories identified in
Attachment 1 FAC-501-WECC-1 as
required in R3.
Severe Severity
Levels defined for
each requirement.

2.4. Severe: There shall be a Severe Level of
non-compliance if any of the following
condition exists:
2.4.1 The TMIP does not include associated
Facilities for more than three of the
Paths identified in the most current
Table titled “Major WECC Transfer
Paths in the Bulk Electric System” as
required by R.1 and Transmission
Owners are not performing maintenance
and inspection for the missing Facilities.
2.4.2 The TMIP does not exist or does not
include more than three maintenance
categories identified in Attachment 1

12

WECC Standard IRO-006-WECC-1 – Qualified
Transfer Path Unscheduled Flow Relief

WECC Standard IRO-STD-006-0 - Qualified Path
Unscheduled Flow Relief

FAC-501-WECC-1 as required by R.2
but Transmission Owners are performing
maintenance and inspection for the
missing maintenance categories.
2.4.3 Transmission Owners are not
performing maintenance and
inspection for more than two
maintenance categories identified in
Attachment 1 FAC-501-WECC-1 as
required in R3.

13

Comment

NERC Regional Reliability Standard Submittal Request Form

Regional Reliability Standard Submittal Request
Region: Western Electricity Coordinating Council
Regional Standard Number: IRO-006-WECC-1
Regional Standard Title: Qualified Transfer Path Unscheduled Flow (USF) Relief
Date Submitted: June 10, 2008
Regional Contact Name: Steven L. Rueckert
Regional Contact Title: Director of Standards
Regional Contact Telephone Number: (801) 582-0353
Request (check all that apply):
Approval of a new standard
Revision of an existing standard
Withdrawal of an existing standard
Urgent Action

Has this action been approved by your Board of Directors (if no please indicate date
standard action is expected along with the current status (e.g., third comment period
with anticipated board approval on mm/dd/year)):
Yes April 16, 2008

No

[Note: The purpose of the remaining questions is to provide NERC with the information
needed to file the regional standard(s) with FERC. The information provided may to a
large degree be used verbatim. It is extremely important for the entity submitting this
form to provide sufficient detail that clearly delineates the scope and justification of the
request.]

Concise statement of the basis and purpose (scope) of request:
The purpose of this standard is to create a permanent replacement standard for IRO-STD-006-0. IRO006-WECC-1 is designed to implement the directives of FERC and recommendations of NERC when
IRO-STD-006-0 was approved as a NERC reliability standard.
Concise statement of the justification of the request:

Version 0.0

-1-

June 15, 2007

NERC Regional Reliability Standard Submittal Request Form

The proposed IRO-006-WECC-1 regional reliability standard contains unscheduled flow curtailment
requirements for the Western Interconnection that are currently cover in IRO-STD-006-0. The NERC
standard IRO-006-4 contains requirements transmission loading relief requirements for the Eastern
Interconnection and only references the WECC regional reliability standard IRO-STD-006-0, which
contains the transmission loading relief requirements for the Western Interconnection.
The WECC regional reliability standard IRO-STD-006-0 and Qualified Path Unscheduled Flow Relief
responsibilities do not conform to the current NERC functional model. The WECC regional reliability
standard IRO-STD-006-0 standard assigns Load Serving Entities (LSEs) the responsibility of curtailing
schedules to reduce unscheduled flow, a reliability function that the NERC functional model now assigns
to Reliability Coordinators and Balancing Authorities. In the functional model, NERC holds that LSEs
should not be assigned responsibility for reliability. Therefore, the assignment of reliability functions to
LSEs is not compatible with the NERC functional model or NERC Standard IRO-006. Additionally, the
existing IRO-STD-006 standard places the sole responsibility for providing relief upon the LSE without
providing the ability for the LSE to ensure compliance (e.g. the Balancing Authority does not have to
approve a curtailment request made by the LSE).
In the proposed IRO-006-WECC-1 standard, responsibility for initiating schedule curtailment is assigned
to the Reliability Coordinators, and the responsibility for implementing the curtailments is assigned to
Balancing Authorities. The proposed standard improves the efficiency of the program including
improved compliance, more certain unscheduled flow relief, and fewer complications associated with
multiple entities taking partial responsibility for curtailment activity.
Other – please attach or include as separate files:
o The text of the regional reliability standard in MS Word format that:
y has either been, or is anticipated to be, approved by the regional entity's
board, and
y is in a format consistent with the NERC template for reliability standards.
o An implementation plan.
o The regional entity standard drafting team roster.
o The names and affiliations of the ballot pool members or names and affiliations of
the committee and committee members that approved the submittal of the
standard.
o The final ballot results, including a list of significant minority issues that were not
resolved, and
o For each public comment period, a copy of each comment submitted and its
associated response along with the associated changes made to the standard.

Version 0.0

-2-

June 15, 2007

NERC Evaluation of Western Electricity Coordinating
Council (WECC) Regional Standards
Executive Summary
July 30, 2008
On June 10, 2008, the WECC submitted the following seven regional standards for
NERC evaluation to replace eight original WECC regional standards approved by NERC and
FERC in 2007:
•
•
•
•
•
•
•

BAL-002-WECC-1 — Contingency Reserves,
FAC-501-WECC-1 — Transmission Maintenance,
IRO-006-WECC-1 — Qualified Transfer Path Unscheduled Flow (USF) Relief,
PRC-004-WECC-1— Protection System and Remedial Action Scheme Misoperation,
TOP-007-WECC-1 — System Operating Limits,
VAR-002-WECC-1 — Automatic Voltage Regulators and
VAR-501-WECC-1 — Power System Stabilizer

NERC posted these seven proposed regional standards for a 45-day public posting beginning April 4–May 20,
2008. The standards received several comments during the NERC public posting. WECC supplied NERC
with its responses to the comments on June 10, 2008. WECC did not make conforming changes to the
standards as a result of the comments received during the NERC posting. WECC submitted these standards
for NERC evaluation on June 10, 2008.
In accordance with NERC’s Rules of Procedure and the Regional Reliability Standards Evaluation
Procedure approved by the Regional Reliability Standards Working Group, NERC performed a
review of the WECC proposed standards. The intent of this document is to provide WECC with
NERC’s feedback regarding their regional standards.
In this review, NERC presents a summary of observations for each proposed WECC
regional standard. In Appendix A, NERC includes a redlined copy of each proposed
regional standard with detailed comments included. NERC believes WECC has satisfied
its procedural obligations as outlined in Appendix C of its Regional Delegation
Agreement. However, NERC offers concerns and suggestions regarding several of the
proposed regional standards that are discussed below.

116-390 Village Blvd.
Princeton, NJ 08540
609.452.8060 | www.nerc.com

Summary of Findings
IRO-006-WECC-1 — Qualified Transfer Path Unscheduled Flow (USF) Relief
1.

NERC is concerned that the technical elements of the proposed standard have been removed
from the current FERC-approved version of the regional standard. As presented, the proposed
standard does not require the mitigation of an overload, which is the express purpose of the
standard. The current version of the standard in effect, IRO-STD-006-0, contains technical
provisions for the mitigation of an overload that supports the purpose statement. These
provisions have not been translated into the proposed replacement standard. NERC requests that
a technical rationale be provided for the removal of the technical details in the proposed standard
because as proposed it is unclear that the revised standard meets the purpose of the standard,
“(m)itigation of transmission overloads due to unscheduled flow on Qualified Transfer Paths.”

2.

The proposed standard includes the term Transfer Distribution Factor (TDF) that is a defined
term in the NERC Glossary. The NERC definition is “(t)he portion of an Interchange
Transaction, typically expressed in per unit that flows across a transmission facility (Flowgate).”
The WECC proposed definition for TDF is “(t)he percentage of USF that flows across a
Qualified Transfer Path when an Interchange Transaction (Contributing Schedule) is
implemented.” [See the WECC Unscheduled Flow Mitigation Summary of Actions Table
(Attachment 1 WECC IRO-006-WECC-1).]
There are inconsistencies between the two definitions that must be resolved. It is not clear if
there are intended differences between the NERC and WECC definitions. If not, NERC suggests
removing the WECC proposed term from the standard. If there are intentional differences,
NERC requests that WECC determine if they are able to utilize the NERC definition, and if not,
to define a new term to accomplish the desired objectives.

3.

The proposed standard contains clear Violation Severity Levels; however, NERC suggests
utilizing the VSL table format to be consistent with the continent-wide standards.

Conclusion
NERC appreciates the opportunity to provide feedback to WECC regarding the seven proposed
regional standards WECC submitted on June 11 2007. In some instances, NERC requests additional
clarification on the issues and concerns outlined in this document. Others provide suggestions for
improving the quality of the proposed regional standards. NERC has included detailed comments
directly in the standards that can be found in Appendix A to this document. NERC has also provided
comments directly into the comparison mapping documents WECC submitted along with the seven
proposed standards in its submittal request.
NERC looks forward to WECC’s response to these comments and ultimately, for WECC’s decision on
whether to request the NERC Board to approve these proposed regional standards.

2

WECC’s Response to NERC’s Comments
August 13, 2008
Draft
INTRODUCTION
WECC appreciates NERC staff’s evaluation of the proposed WECC Regional Reliability
Standards (RRSs) in accordance with NERC’s Regional Reliability Standards Evaluation
Procedure. These proposed WECC RRSs were developed as permanent replacements for
the eight WECC Tier 1 RRSs that previously were approved by NERC and FERC.
WECC asserts that the seven proposed standards contain all the performance elements of
a Reliability Standard that are contained in the NERC Reliability Standards Development
Procedure. In addition, the seven proposed standards address and implement the
refinements directed by FERC’s order on June 8, 2007 (see FERC Docket No.
RR07-11-000) and requested by NERC in its letter dated January 9, 2007. Finally, these
proposed standards implement refinements to the approved WECC Tier 1 RRSs which
were recommended during the previous expedited direct translation standard
development processes.
The attached WECC responses individually address each NERC comment. However,
many of the comments submitted by NERC staff relate to refinements that NERC has
made to the format of its Reliability Standard Template. These refinements have not been
formally approved by NERC, nor have they been transmitted to the regions for comment
or additional information, and were therefore unavailable to WECC during the
development process. Consequently, WECC has determined not to reopen the standards
development process at this stage to address these non-substantive formatting concerns.
In addition, during the standards development process, WECC staff twice requested that
NERC staff review the proposed WECC standards. WECC did this to ensure that the
WECC standard drafting teams were complying with NERC’s Regional Reliability
Standards Evaluation Procedure as well as its Reliability Standards Development
Procedure. NERC did not perform the evaluation of these proposed standards until
WECC had completed its Process for Developing and Approving WECC Standards.
WECC intends to implement the requested formatting refinements and any potential
FERC-directed changes during the next revision of these standards or the next FERC
compliance filing.
The proposed WECC RRSs were considered and adopted pursuant to the Process for
Developing and Approving WECC Standards. Unless they are approved in their current
form, WECC will have to reinitiate the entire process. The consequences of rejecting
these WECC RRSs in their entirety would be counterproductive to reliability in the
Western Interconnection.
The proposed WECC RRSs will enhance reliability in the Western Interconnection and
they will significantly improve the existing eight WECC RRSs because they:
1. Implement ordered NERC and FERC refinements to the existing standards
ordered;

1

2. Eliminate conflicting NERC and WECC requirements contained in the existing
RRSs;
3. Include all the Performance Elements of a Reliability Standard;
4. Clarify existing WECC RRSs;
5. Align better with NERC’s Functional Model, and
6. Address industry stakeholder concerns.
Therefore, WECC requests the NERC staff recommend approval of these standards to the
NERC Board and FERC.
WECC’s responses to NERC’s initial evaluation are provided in Attachment 1.

2

Attachment 1
NERC’s Written Comments
July 30, 2008
WECC’s Written Responses
August 13, 2008

Summary of Findings
IRO-006-WECC-1 — QUALIFIED TRANSFER PATH UNSCHEDULED FLOW
(USF) RELIEF
NERC COMMENT:
1.

NERC is concerned that the technical elements of the proposed standard have been
removed from the current FERC-approved version of the regional standard. As
presented, the proposed standard does not require the mitigation of an overload, which
is the express purpose of the standard. The current version of the standard in effect,
IRO-STD-006-0, contains technical provisions for the mitigation of an overload that
supports the purpose statement. These provisions have not been translated into the
proposed replacement standard. NERC requests that a technical rationale be provided
for the removal of the technical details in the proposed standard because as proposed it
is unclear that the revised standard meets the purpose of the standard, “(m)itigation of
transmission overloads due to unscheduled flow on Qualified Transfer Paths.”

WECC RESPONSE:
1. The proposed IRO-006-WECC-1 Standard contains all the key reliability requirements
and technical elements from the Unscheduled Flow Mitigation Plan (UFMP) that were
included in IRO-STD-006-0. The proposed IRO-006-WECC-1 Standard uses NERC’s
Functional Model terminology to mitigate unscheduled flow during the next operating
hour. It is not necessary to reference the remainder of the UFMP because the remaining
items contain procedural requirements explaining “how,” not “what.” The proposed
IRO-006-WECC-1 Standard includes requirements to reduce schedules, which then
require adjustments to generation patterns. This prevents potential overloads during the
next operating hour. Importantly, the requirements for mitigation of an actual (realtime) overload are contained in TOP-007-WECC-1.
NERC COMMENT:
2.
The proposed standard includes the term Transfer Distribution Factor (TDF) that is a
defined term in the NERC Glossary. The NERC definition is “(t)he portion of an
Interchange Transaction, typically expressed in per unit that flows across a transmission
facility (Flowgate).” The WECC proposed definition for TDF is “(t)he percentage of
USF that flows across a Qualified Transfer Path when an Interchange Transaction
(Contributing Schedule) is implemented.” [See the WECC Unscheduled Flow
Mitigation Summary of Actions Table (Attachment 1 WECC IRO-006-WECC-1).]

3

There are inconsistencies between the two definitions that must be resolved. It is not
clear if there are intended differences between the NERC and WECC definitions. If
not, NERC suggests removing the WECC proposed term from the standard. If there are
intentional differences, NERC requests that WECC determine if they are able to utilize
the NERC definition, and if not, to define a new term to accomplish the desired
objectives.
WECC RESPONSE:
2. WECC acknowledges the difference between the NERC and WECC definitions for
Transfer Distribution Factor (TDF). This is caused by the differences between the
Eastern Interconnection Transmission Loading Relief process and the Western
Interconnection UFMP. This difference in definitions exists even today between the
existing FERC-approved IRO-STD-006-0 Standard and the NERC Glossary. Rejecting
the proposed standard will not resolve this difference. WECC will work with NERC to
resolve this and intends to make any necessary refinements during the next revision of
this standard or the next FERC compliance filing. Despite the difference in the TDF
definitions, the proposed standard corrects a basic difference between the existing
FERC-approved IRO-STD-006-0 Standard, which places reliability
responsibilities upon the Load Serving Entities (LSEs), and the NERC Functional
Model. LSEs do not have the ability to ensure the implementation of the schedule
adjustments required in the existing FERC-approved IRO-STD-006-0 Standard.
NERC COMMENT:
3. The proposed standard contains clear Violation Severity Levels; however, NERC
suggests utilizing the VSL table format to be consistent with the continent-wide
standards.
WECC RESPONSE:
1. WECC recognizes the unapproved NERC Reliability Standard Template requires the
placement of VSLs in a table. As stated previously, WECC intends to implement this
refinement during the next revision of this standard or the next FERC compliance filing.
(NERC) CONCLUSION
NERC appreciates the opportunity to provide feedback to WECC regarding the seven
proposed regional standards WECC submitted on June 11 2007. In some instances, NERC
requests additional clarification on the issues and concerns outlined in this document. Others
provide suggestions for improving the quality of the proposed regional standards. NERC has
included detailed comments directly in the standards that can be found in Appendix A to this
document. NERC has also provided comments directly into the comparison mapping
documents WECC submitted along with the seven proposed standards in its submittal
request.
NERC looks forward to WECC’s response to these comments and ultimately, for
WECC’s decision on whether to request the NERC Board to approve these proposed
regional standards.

4

WECC RESPONSE
WECC appreciates the opportunity to discuss NERC staff’s initial evaluation and report
in conference calls on August 4 and 5, 2008 and to provide the written clarifications and
responses contained herein. We trust that WECC’s responses, along with all the
supporting documentation contained in WECC’s submissions, provide the NERC staff a
comprehensive basis for recommending NERC Board of Trustees approval of all
proposed standards. Please direct any questions relating to WECC’s response to WECC
Director of Standards, Steve Rueckert at [email protected] or (801) 883-6878.

5

Steven L. Rueckert

Director of Standards
801.582.0353 ext. 6878
[email protected]

August 18, 2008

Gerard Adamski
Vice President and Director of Standards
North American Electric Reliability Corporation
116-390 Village Boulevard
Princeton, New Jersey 08540-5721
RE: WECC’s response to NERC’s initial evaluation of seven WECC regional reliability
standards
Dear Gerry,
WECC appreciated the opportunity to discuss NERC staff’s initial evaluation of the seven
WECC regional reliability standards in conference calls on August 4 and August 5. Attached are
WECC's written clarifications and responses to the concerns and issues identified in NERC’s
written evaluation on July 30 and the subsequent conference calls.
We trust that WECC’s responses, along with the supporting documentation contained in
WECC’s submissions, provide the NERC staff a comprehensive basis for recommending NERC
Board of Trustees approval of the seven proposed regional reliability standards. Please direct any
questions relating to WECC’s response to WECC’s Director of Standards, Steve Rueckert at
[email protected] or (801) 883-6878 or Ken Wilson at [email protected] or (801) 883-6886.
Sincerely yours,
Steve Rueckert
Steven L. Rueckert
SR:
Attachment
Cc: Stephanie Monzon, NERC
Thomas J Schneider, WECC

W E S T E R N E L E C T R I C I T Y C O O R D I N A T I N G C O U N C I L • W W W . W E C C . B I Z
615 ARAPEEN DRIVE • SUITE 210 • SALT LAKE CITY • UTAH • 84108-1262 • PH 801.582.0353 • FX 801.582.3918

UFAS STANDARD DRAFTING TEAM
WHITE PAPER
This paper discusses and attempts to clarify the DRAFT IRO-006-WECC-1 Standard
posted for comment. The UFAS Standard Drafting Team (UFAS SDT) met on several
occasions to draft a permanent replacement for IRO-STD-006-0 -- Qualified Path
Unscheduled Flow Relief, which FERC approved on June 8, 2007.
Background:
On Friday June 8, 2007, the Federal Energy Regulatory Commission (FERC) issued an
order approving the Western Electricity Coordinating Council (WECC) WECC-IROSTD-006-0 (Qualified Path Unscheduled Flow Relief) Standard, which is one of the Tier
1 Regional Standards. This WECC regional reliability standard was developed using
WECC’s Expedited Process for Urgent Action Interim Standards. The WECC Process
requires that Interim Standards must have a termination date no longer than one year
from the date of implementation. Interim Standards must be converted to permanent
Standards or successor standards must be developed. The permanent/replacement
standards must comply with the NERC requirements for regional reliability standards
including removal of the RMS Sanction Table and use of the NERC sanction table for
enforcement purposes and address the directives in the June 8, 2007 FERC order.
The Triage Committee (Standards Request Routing Committee) identified the WECC
Operating Committee (OC) as the lead Standing Committee for the Tier One Standards,
and the OC has assigned the Unscheduled Flow Administrative Subcommittee (UFAS) to
take the lead on project WECC-0024/Unscheduled Flow Relief developing a
permanent/replacement regional reliability standard. A standards drafting team (SDT)
was formed for project WECC-0024/Unscheduled Flow Relief. Upon approval by
FERC, WECC regional reliability standards become part of the body of the NERC
Reliability Standards and will be enforced through monetary sanctions in the United
States. The SDT is posting a draft standard for comment on the WECC website.
The UFAS SDT reviewed the recently approved standard and considered all comments
received, including comments submitted by FERC and NERC. The SDT discussed
several approaches to the task. During discussions, several aspects of the current plan
were discussed and recommendations were made to modify the standard to make it more
effective at mitigating Unscheduled Flow and enhance the reliable operation of the
Western Interconnection. Results of a straw poll taken at the June, 2007 WECC OC and
MIC meetings indicated support for a shift of responsibility in the Contributing Schedule
curtailment portion of unscheduled flow mitigation. As a result, the SDT decided to
implement a change in responsibility for initiating schedule curtailments.
Qualified Path Unscheduled Flow Relief Criterion in RMS and IRO-STD-006-0:
The Qualified Path Unscheduled Flow Relief responsibilities do not conform to the
current NERC functional model. This RMS Criterion and currently-approved standard
assigns Load Serving Entities (LSE’s) the responsibility of curtailing schedules to reduce
unscheduled flow, a reliability function that the NERC functional model now assigns to

Reliability Coordinators and Balancing Authorities. In the functional model, NERC
holds that LSEs should not be assigned responsibility for reliability. Therefore, the
assignment of reliability functions to LSEs is not compatible with the NERC functional
model or NERC Standard IRO-006. Additionally, the existing RMS and IRO-STD-006
standards place the sole responsibility for providing relief upon the LSE without
providing the ability for the LSE to ensure compliance (e.g. the Balancing Authority does
not have to approve a curtailment request made by the LSE). The LSE through the
webSAS program emulates a Reliability Coordinator. With the WebSAS tool, the LSE
can only enter a curtailment, but this curtailment may be denied by a Balancing
Authority. The LSE cannot ensure implementation of the requested reliability
curtailments. When IRO-STD-006 was approved, FERC directed WECC to address
these concerns in developing a permanent replacement reliability standard. (See
paragraphs 71 and 72 in the FERC Order in Docket RR07-11-000.) For these reasons,
the drafting team recommends that LSEs should not be assigned reliability functions such
as curtailments. In the proposed IRO-006-WECC-1 standard, responsibility for initiating
schedule curtailment is assigned to the Reliability Coordinators, and the responsibility for
implementing the curtailments is assigned to Balancing Authorities. The proposed
standard should improve the efficiency of the program including improved compliance,
more certain Unscheduled Flow relief, and fewer complications associated with multiple
entities taking partial responsibility for curtailment activity.
Explanation of the Standard:
The SDT essentially boiled the standard down to two Requirements and two Measures:
Explanation of REQUIREMENT 1:
Once the Transmission Operator calls upon the UFMP at a level that requires some
degree of off-path tag curtailments, the Transmission Operator notifies its corresponding
Reliability Coordinator (RC) that it is requesting Contributing Schedule curtailments.
Upon determining the request is appropriate, the RC must utilize the webSAS software to
initiate the required tag curtailments. Curtailments are envisioned to be based upon either
the exact prescription of curtailments specified in the table of curtailment actions of the
Unscheduled Flow Mitigation Plan (UFMP) or upon the order of highest transfer
distribution factor tags curtailed first—a pre-selection of preferred option may be made
by each Load Serving Entity. This means that the Unscheduled Flow Mitigation Plan
(UFMP) will be administered just as it is today with the exception that, instead of over
one hundred LSEs determining which tags to curtail, a single RC shall initiate schedule
curtailments with a single command for all entities through the webSAS software.
Explanation of REQUIREMENT 2:
Once the Source and Sink Balancing Authorities receive Curtailment requests through
their tagging systems, the Balancing Authorities’ must actively approve the curtailment
request; implement alternative actions that provide the Relief Requirement; or a
combination thereof that collectively meets the Relief Requirement. This requirement
does not change any part of the UFMP as today Balancing Authorities should actively
approve all curtailment requests.

Explanation of MEASURE 1:
Requirement 1 is considered to be met if any RC in any of the Reliability Centers sends
the command to initiate curtailments using the webSAS tool. The final state of the tags
with pending curtailment requests are not at issue. The measure merely assures that the
RC initiates the curtailment process.
Explanation of MEASURE 2:
Requirement 2 is considered to be met if each Sink Balancing Authority who has
authority to approve or deny the curtailment requests, in fact, approves the curtailment
requests or provides alternative action such as generation redispatch, phase-shifter
operation, DC circulation, or some combination thereof. If the Balancing Authority does
not implement a requested curtailment or alternative actions are not implemented, then
Requirement 2 has not been met.
Discussion:
It is the intent of the UFAS SDT that the UFMP shall continue to be the WECC plan to
mitigate Qualified Path unscheduled flow in the Western Interconnection and that the
Plan continues to be implemented exactly as it is today with the one exception that the
LSE no longer initiates the curtailments to their own tags. The reasons for this are
several:
1. Most LSEs do not enjoy the level of choice as to which tags to curtail as had been
envisioned when the webSAS tool was implemented,
2. LSEs who are not WECC members do not take the opportunity to register and, as
a result, avoid the responsibility for the curtailments; this responsibility then
defaults to the Sink Balancing Authority to initiate the cuts, putting the Balancing
Authorities at an increased risk for incurring a violation,
3. LSEs have no control over whether the curtailments that they request are
approved. The Standard now only requires that the responsible party – the RCs
initiate a curtailment,
4. LSEs may retain some choice in determining which curtailments are enacted as
UFAS intends to modify the webSAS tool to permit LSEs the option to select
either (1) curtailments from highest Transfer Distribution Factors to lowest until
compliance is reached, or (2) select curtailments of all contributing schedules as
prescribed by the table of curtailment actions in the UFMP, with the latter as the
default choice.
It is not the intent of the UFAS SDT to burden the RCs. Today when a Transmission
Operator requests a step 4 or above curtailment, the RC is usually involved in making the
decision since it is responsible for reliability. Requiring the RC to initiate the curtailment
process allows the RC the opportunity to assess the request and override the request if
necessary. If the RC takes no action, it is expected that the webSAS software will initiate
curtailments automatically. This process will also minimize any further Balancing
Authority action regarding curtailments.

The refinements implemented through the proposed IRO-006-WECC-1 standard should
1. Result in consistent curtailments at the proper level,
2. Remove the lack of action as an impediment to achieving the proper
curtailments,
3. Relieve the LSEs of the burden of deciding which action should be taken,
allowing them to spend their time initiating the scheduling of energy to replace
that curtailment with schedules that either relieve the constrained path or are
impact neutral,
4. Place the control of reliability actions back with reliability-trained personnel, and
5. Significantly reduce compliance auditing for LSEs and WECC Staff to determine
compliance with the plan.
The USF SDT includes representatives from the RCs, Constrained Path Transmission
Operators, and LSEs. The proposed standard has included input from these parties. We
believe the proposed standard satisfies their concerns and has their support.
Members of the drafting team have held discussions with the webSAS vendor and believe
the necessary software modifications to ensure implementation of this standard can be
satisfied without undue burden on any party.
The USF SDT requests that your organization support the refinements to UFMP and
recognize that the proposed standard improves the efficiency of the plan and more
importantly, reliable operation of the Interconnection.

It is WECC’s position that both the existing IRO-STD-006-0 Regional Reliability Standard and
the proposed IRO-006-WECC-1 Regional Reliability Standard contain requirements that address
items not included in NERC’s IRO-006-4 Reliability Standard.
The following is a listing of each requirement of NERC’s IRO-006-4 standard, identifying how
these requirements apply or do not apply to WECC entities. Also provided is a summary of the
requirements in the proposed IRO-006-WECC-1 Regional Reliability Standard, identifying why
they address items not included in NERC’s IRO-006-4 Reliability Standard. Excerpts from the
current FERC-approved IRO-STD-006-0 Regional Reliability Standard, explaining what is
actually required and how it is currently enforced are also provided below.
NERC comments/questions in blue.
NERC IRO-006-4
The applicability section of NERC’s IRO-006-4 Reliability Standard identifies RCs, TOPs, and
BAs. Of the 5 requirements, the first four include specific requirements of the RC. Requirement
5 includes requirements of the RC and BA. None of the requirements identify anything that a
TOP must do, even though the TOP is included in the Applicable Entities section.
Andy Rodriquez has clarified that while R1- R5 do not assign responsibilities to the TOP the
TLR attachment to the standard establishes requirements for the TOP. The TLR procedure is
enforceable.
Requirement 1
A Reliability Coordinator experiencing a potential or actual SOL or IROL violation within its
Reliability Coordinator Area shall, with its authority and at its discretion, select one or more
procedures to provide transmission loading relief. These procedures can be a “local” (regional,
interregional, or sub-regional) transmission loading relief procedure or one of the following
Interconnection-wide procedures:
This requirement requires the RC to select one or more procedures to provide transmission
loading relief in instances where an RC is experiencing a potential or actual SOL or IROL. This
requirement does NOT require the RC use any specific procedure, but only requires the RC to
select one or more.
NERC clarifies that some of the procedures include requirements that action is taken if steps to
provide relief have been exhausted beyond the local/sub-regional procedures.
The three sub-requirements of Requirement 1 identify the three existing interconnection-wide
procedures. Sub-requirement R1.2 incorrectly identifies WECC Tier 1 Standard IRO-STD-0060 as the WECC interconnection-wide procedure. It should identify the WECC Qualified Path
Unscheduled Flow Procedure. This requirement, in its sub-requirements identifies the existing
interconnection-wide procedures, but does not require the RC to select the interconnection-wide
procedure.
Andy and the drafting team members (of the continent wide IRO-006 Project 2007-xx) will be
discussing the current reference to the WECC IRO standard.

Formatted: Font color: Blue

Requirement 2
The Reliability Coordinator shall only use local transmission loading relief or congestion
management procedures to which the Transmission Operator experiencing the potential or
actual SOL or IROL violation is a party.
This requirement does not apply to the Interconnection-wide procedure, only local procedures.
The WECC USF is an interconnection-wide procedure so this requirement does not apply to the
WECC USF procedure. Additionally, the WECC USF Procedure is only applicable to six
qualified paths, which are operated by three different Transmission Operators. Therefore the
only time a WECC RC can select this plan is if the potential or actual SOL or IROL is on one of
the six qualified paths.
The TOP-007-WECC-1 standard references the WECC Major Transfer Paths. The referenced
document (the link in the standard) indicates that there are 40 of these paths. These are the paths
that the TOP must ensure to reduce PF in the case that they exceed SOL. The IR0-006-WECC-1
standard as stated above is applicable to only six qualified paths operated by three Transmission
Operators.

Requirement 3
Each Reliability Coordinator with a relief obligation from an Interconnection-wide procedure
shall follow the curtailments as directed by the Interconnection-wide procedure. A Reliability
Coordinator desiring to use a local procedure as a substitute for curtailments as directed by the
Interconnection-wide procedure shall obtain prior approval of the local procedure from the
ERO.
The WECC USF Procedure does not require the RC to take any actions nor does it obligate the
RC to provide relief. Therefore, this requirement is not applicable to WECC RCs.
Requirement 4
When Interconnection-wide procedures are implemented to curtail Interchange Transactions
that cross an Interconnection boundary, each Reliability Coordinator shall comply with the
provisions of the Interconnection-wide procedure.
As noted for Requirement 3, the WECC USF Procedure does not contain any requirements
applicable to the RC. Therefore, this requirement is not applicable to WECC RCs either. The
wording in this requirement appears to be specifically targeted at the RCs in the Eastern
Interconnection or the Western RC if the event is initiated in the East.
Requirement 5
During the implementation of relief procedures, and up to the point that emergency action is
necessary, Reliability Coordinators and Balancing Authorities shall comply with applicable
Interchange scheduling standards.
This requirement is applicable to the RC and BA, but has no impact on nor is it related to the
interconnection-wide procedure. It requires the BA and RC to comply with NERC standards
INT-001, INT-003, and INT-004 during the implementation of the interconnection-wide

procedure. This means that BAs and RCs within WECC must comply with these three NERC
INT standards during the implementation of the USF Procedure. WECC does not dispute this.
WECC IRO-006-WECC-1
Requirement 1
Upon receiving a request of Step 4 or greater (see Attachment 1-IRO-006-WECC-1) from the
Transmission Operator of a Qualified Transfer Path, the Reliability Coordinator shall approve (actively
or passively) or deny that request within five minutes.
The WECC USF Procedure does not contain any requirements applicable to the RC. Requirement 1 of
IRO-006-WECC-1 requires the RC, as the entity responsible for the reliability of the interconnected
system, to approve or deny a request for initiation of curtailments from one of the three Qualified Path
Operators. The purpose of this requirement is to allow the RC to deny a request to initiate curtailments if
the request does not meet the reliability levels set out by the procedure.
Requirement 2
The Balancing Authorities shall approve curtailment requests to the schedules as submitted, implement
alternative actions, or a combination there of that collectively meets the Relief Requirement.
Because the old IRO-STD-006-0 included requirements applicable to the LSE, it was possible that a tag
curtailing schedules could be submitted, but not approved, resulting in no reduction of the potential SOL
or IROL. However, because of the way the standard is currently written, compliance is achieved.
Automation now identifies the schedules to be curtailed, and upon approval by the RC, Requirement 2 of
IRO-006-WECC-1 makes it mandatory for the BA to approve the tag, resulting in curtailments of
contributing schedules or provide relief through another method.
Existing Standard Interpretation
NERC indicates that the WECC USF procedure is mandatory in the current approved Tier 1 standard
because it is referenced in the language of the standard. However, a review of the measures and levels of
non-compliance all pertain to actions taken by responsible entities, as requested by the Qualified Path
TOP. The existing levels of non-compliance are all based on the amount of relief that was not provided,
and have nothing to do with the sequential or actual implementation of the steps identified in the
Qualified Path Unscheduled Flow Relief Procedure. Excerpts from the requirement of the existing IROSTD-006-0 follow:
Requirement WR1
“members2/ shall comply with requests from (Qualified) Transfer Path Operators to take actions that will
reduce unscheduled flow on the Qualified Path in accordance with the table entitled “WECC
Unscheduled Flow Procedure Summary of Curtailment Actions,” which is located in Attachment 1 of the
Plan.”
The first three steps of the table entitled “WECC Unscheduled Flow Procedure Summary of Curtailment
Actions” are actions that must be implemented by the Qualified Path Operator. Steps 4 through 9 are
steps that must be taken by applicable entities in response to a request from a Qualified Transfer Path
Operator. As stated in the requirement, it is only steps 4 through 9 than can be requested by a Qualified
Transfer Path Operator.
Measure M1

Responsible Entities shall take actions as requested by Qualified Transfer Path Operators that result in
the specified amount of Unscheduled Flow Relief for the applicable Qualified Transfer Path. These
actions include, but are not limited to, one or a combination of schedule curtailments, schedule increases,
and operation of non-Qualified Controllable Devices.
The actions that FERC identifies as making the WECC procedure superior to the Eastern Interconnection
TLR procedure are all actions that are taken by the Qualified Path Operator. The existing standard
identifies only one requirement, which is for the Responsible Entity to provide Unscheduled Flow Relief
as determined by the Plan. The Plan only determines relief requirements based on transactions, not
coordinated operation of phase shifters or accommodation. Therefore, there is no measurement related to
the language that NERC staff has pointed to related to the use of the controllable devices or any level of
accommodation. While the NERC staff interpretation might be a more desirable position, it is not
supported by the language in the existing standard, historical practice in the WECC or the interpretation
of the drafting team that was tasked with re-writing the existing standard as ordered by FERC.
Summary
NERC standard IRO-006-4 requires the RC to select one or more procedures to relieve potential or actual
SOLs and IROLs. It does not require an interconnection-wide procedure to be selected, but it identifies
the three existing interconnection-wide procedures in place. It places certain limits on which procedures
may be selected, and arguably may require the RC to adhere to provisions of the interconnection-wide
procedure if the interconnection-wide procedure is selected (NOTE: The WECC procedure does not
contain any requirements applicable to the RC), although R3 really only says that the RC must follow the
curtailment requests of the Interconnection-wide procedure, not follow all steps of the interconnectionwide procedure..
WECC’s proposed IRO-006-WECC-1 requires the RC to either approve or deny a request by a Qualified
Path TOP (of which there are only 3) to initiate schedule curtailments in a reasonable timeframe, and
requires the BA to implement curtailments (approve tags) or alternative actions to achieve the same relief.
NERC’s IRO-006-4 Reliability Standard requires RC’s to select a plan. The WECC standard requires the
RC to approve or reject a request for curtailment and the BA to implement the curtailments if approved by
the RC. The WECC standard addresses items not covered in the NERC standard.

Taken from the UFAS Standard Drafting Team White Paper:
“In the proposed IRO‐006‐WECC‐1 standard, responsibility for initiating schedule curtailment is assigned 
to the Reliability Coordinators, and the responsibility for implementing the curtailments is assigned to 
Balancing Authorities.  The proposed standard should improve the efficiency of the program including 
improved compliance, more certain Unscheduled Flow relief, and fewer complications associated with 
multiple entities taking partial responsibility for curtailment activity” 

As IRO‐006‐WECC‐1 is proposed the RC does not initiate curtailments but rather responds to curtailment 
requests from the TOP. Two questions regarding 

Questions on IRO-006-WECC-1

December 1, 2008
NERC appreciates the opportunity to work with WECC to clarify concerns with the
proposed IRO-006-WECC-1 standard. This standard is intended to replace the existing IRO-STD-006-1
standard approved by FERC. NERC staff has identified two main concerns with the IRO-006-WECC-1
standard.
Question 1:
NERC understands by way of explanation that WECC uses TOP-007-WECC-1 to manage the transfer path
power flow on the Major WECC Transfer Paths (using local and other relief procedures to ensure that power
flows do not exceed SOL for more than 30 minutes). NERC also understands that IRO-006-WECC-1 is used
to ensure that RC’s are responding to curtailment requests by the TOPs on six of these transfer paths. NERC
identified one path, Path Code 23, the APS Four Corners path that is not included in the list of Major Transfer
Paths. This would mean that TOP-007-WECC-1 does not apply to this path and as such the TOP is not
actively monitoring power flows and taking immediate action to relieve flow as to not exceed its SOL. Is there
a gap that needs to be filled for this transmission path? Is it correct to interpret that curtailments on the other
34 paths not covered under IRO-006-WECC-1 would not provide relief?
Question 2:
The following is an excerpt taken from the UFAS Standard Drafting Team White Paper:
“In the proposed IRO-006-WECC-1 standard, responsibility for initiating schedule
curtailment is assigned to the Reliability Coordinators, and the responsibility for
implementing the curtailments is assigned to Balancing Authorities. The proposed
standard should improve the efficiency of the program including improved compliance,
more certain Unscheduled Flow relief, and fewer complications associated with multiple
entities taking partial responsibility for curtailment activity”
However, it is NERC’s interpretation that the proposed IRO-006-WECC-1 standard does not require the RCs
to initiate curtailments, but rather only respond to curtailment requests from the TOP. Based on previous
discussion regarding TOP-007-WECC-1, and our reading of IRO-006-WECC-1, it is our understanding that
the TOP initiates these schedule curtailments, not the RC. Is this correct? If not, please explain further (e.g.,
is this a function of the OATI webSAS tool, where the TOP makes the request but the RC actually “initiates”
the curtailment by confirming the request?).

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Secondly, what recourse does the TOP within WECC have if the RC denies the request for curtailment? Does
the TOP have a wide-area view through webSAS, such that they are aware of other options if their requests
are denied by an RC? If not, what steps would occur following the RC denial?
As discussed on the conference call on November 19, 2008 WECC will be preparing a paper that explains the
interaction between the TOP-007-WECC-1 and IRO-006-WECC-1 standards. In particular, the paper is to
include an explanation of the process flow of managing SOLs on the transfer paths in TOP-007-WECC-1 and
for mitigating unscheduled flow on transfer paths in IRO-006-WECC-1. NERC looks forward to the paper as
it may clarify these remaining concerns.

2

Interaction between TOP-007-WECC-1 and IRO-006-WECC-1
NERC’s Concern
During the conference call on November 19, 2008 between members of the NERC staff
and WECC, NERC identified a concern that the WECC proposed replacement standard
IRO-006-WECC-1 removed a requirement for the Transmission Operator (TOP) to
request relief through the WECC Qualified Path Unscheduled Flow Relief Procedure
when a qualified transfer path exceeded or was close to exceeding a System Operating
Limit (SOL). NERC interprets the existing interim WECC regional reliability standard,
IRO-STD-006-0, as requiring such action by the TOP.
In response to this concern, WECC staff indicated that the requirements of another
WECC regional reliability standard, TOP-STD-007-0 (interim approved Tier 1 standard),
as well as the WECC proposed replacement regional reliability standard TOP-007WECC-1, require the TOP to take actions to ensure that SOLs are not exceeded. WECC
volunteered to prepare a paper that explains the interaction between the TOP-007WECC-1 and IRO-006-WECC-1 regional reliability standards. In particular, this paper
identifies the link between the process flow of managing SOLs on the transfer paths in
TOP-007-WECC-1 and for mitigating unscheduled flow on qualified transfer paths in
IRO-006-WECC-1.
Interaction between TOP-007-WECC-1 and IRO-006-WECC-1
WECC regional reliability standard TOP-007-WECC-1 includes a requirement that TOPs
are responsible for keeping path flows and schedules at or below SOLs for the 40 paths
identified in Attachment A, Table 2, of the existing interim standard and referenced in the
proposed TOP-007-WECC-1 replacement regional reliability standard. TOPs, in
coordination with the Reliability Coordinators, may select from several methods
including but not limited to the following:
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On path schedule Curtailments
Adjust controllable devices (e.g. phase shifters, series capacitors, FAC devices)
WECC Reliability Coordinator Procedure RC-003-1
Generation patterns adjustments
DC circulation
Local procedures
The WECC Unscheduled Flow Mitigation Plan (UFMP) if the path experiencing
the loading is a qualified path
Emergency Transmission Overload Procedure
Re-configure transmission
Load Curtailment, including firm, DSM, or interruptible load.

TOP-007-WECC-1 contains real-time requirements for TOPs of the 40 major paths to
keep flows at or below SOLs. When SOLs are exceeded, TOP-007-WECC-1 requires
that TOPs take immediate action to reduce path flows to within limits. The period for the

path flow reduction shall not exceed 30 minutes from the time the path flow is greater
than the SOL. The reason for the SOL being exceeded does not matter. Besides the
scheduled flows on the path, additional flow may be caused by an outage, a change in
load, or changes in generation patterns. In addition to these causes, additional flow
caused by unscheduled, or circulating flow, from scheduled flows on other paths, has the
ability to increase flow on the path, potentially leading to exceeding SOLs. These
scheduled flows on other paths that cause circulating flow are often times beyond the
control of the TOP of the path on which the SOLs are exceeded. When this happens, the
TOP may have to implement more than one of the procedures listed above to comply
with TOP-007-WECC-1.
The WECC UFMP includes the WECC Unscheduled Flow Reduction Procedure. Within
the Unscheduled Flow Reduction Procedure is a section on Transfer Path Qualification.
This section identifies qualifying factors a path must meet for that path to be considered a
Qualified Path for purposes of the UFMP. One of these qualifying factors is that the path
experienced at least 100 hours during the most recent 36 months where actual flow across
the transfer path exceeded 97 percent of the maximum transfer limit and energy
schedules were curtailed because of unscheduled flow.
There are currently six paths in the WECC that meet these qualifying requirements. The
six Qualified Paths listed in the UFMP are all included or associated with paths identified
as the 40 major paths referenced in TOP-007-WECC-1. If any of these six Qualified
Paths exceed an SOL, TOP-007-WECC-1 requires that the TOP take immediate action to
reduce the actual power flow across the path. The key point here is that it is TOP-007WECC-1, not IRO-006-WECC-1, that requires the TOP to take actions to reduce flows to
within SOLs.
Path 23 from the list of Qualified Paths is not included in Attachment A, Table 2, of
TOP-007-WECC-1, but is operated in series with Path 22, which is included in the
attachment. Arizona Public Service Company, Path Operator for Path 22 and Path 23,
has indicated that the only time Path 23 is impacted is when the Four Corners Unit 5 is
off line. In these limited instances, unscheduled flow becomes an issue on Path 23.
However, in these situations, Path 23 is operated in series with, and is the limiting factor,
for Path 22. Therefore, mitigation efforts for any potential overloads on Path 22 result in
mitigation of any potential overloads on Path 23.
Because of the physical nature of the Bulk Electric System in the Western
Interconnection, there are times when circulating flows, caused by schedules other than
those on path schedules of the TOP, result in significant flows across these Qualified
Paths eventually resulting in flows that exceed the SOLs. The TOP, to comply with
TOP-007-WECC-1, must take actions to reduce these flows below SOLs. Off-path
schedules that cause this unscheduled flow across the Qualified Paths are referred to as
Contributing Schedules. In those situations where the TOP has taken action to reduce the
flows on a Qualified Path (operation of controllable devices, accommodation, and
coordinated operation of phase shifters) and yet, because of Contributing Schedules, the
flows are still near or exceeding the SOLs, IRO-006-WECC-1 requires curtailment of

Contributing Schedules or provision of comparable relief through other means, as
identified in the Unscheduled Flow Reduction Procedure, so that the TOP of the
Qualified Path can keep the actual flow within the SOLs.
Implementation of UFMP is one of the options available to the TOP to prevent potential
violations of TOP-007-WECC-1. If the TOP is able to take other actions to keep actual
flows within SOLs, the TOP may not need or desire to utilize the UFMP. However, if
after taking actions identified in the UFMP, the TOP is still experiencing significant
flows on a Qualified Path, the TOP may initiate the UFMP to obtain relief from the
Contributing Schedules, thus reducing the actual flows to within SOLs. It is not
absolutely necessary that the TOP of a Qualified Path implement the UFMP to manage
flows to within SOLs to comply with TOP-007-WECC-1. However, if the TOP chooses
the UFMP as one of the alternatives to manage flows, the requirements of IRO-006WECC-1 make it mandatory for entities with Contributing Schedules to curtail these
schedules, upon approval by the RC, to provide the necessary relief.
A TOP does not have to wait until a SOL is exceeded to use the Unscheduled Flow
Reduction Procedure in the UFMP. A TOP may implement the UFMP procedures once
actual flow across the qualified path reaches or exceeds 95% of the SOL.
When the TOP of a qualified path determines that the UFMP is one of the preferred flow
reduction solutions, it then follows the steps contained in the UFMP. The procedure in
the UFMP contains both current hour adjustments and next hour adjustments as follows:
Current hour adjustments-Step 1: Adjust on path controllable devices to reduce path flow.
Step 2: Curtail on-path schedules so that total on-path schedules are at least the
greatest of 50 MW or 10% below the SOL.
Step 3: The controllable device owners operate their controllable device in a
coordinated manner to reduce unscheduled flow (USF).
Next hour adjustments (Process to be followed upon implementation of IRO-006WECC-1) –
Step 4 or higher off path schedule curtailments
The TOP submits a request to its Reliability Coordinator (RC) for off-path schedule
curtailments per Steps 4 through 9 in the UFMP. The TOP submits its request through
the OATI webSAS tool to the RC. Requirement 1 of IRO-006-WECC-1 requires the RC
to approve or deny the request using the webSAS tool. Unless the RC denies the request
for reliability reasons, the webSAS tool, through preprogrammed algorithms, determines
the curtailment amount for each of the approved steps and automatically submits the
schedule curtailments. Requirement 2 of IRO-006-WECC-1 requires Balancing
Authorities to approve curtailment requests to the schedules as submitted, implement

alternative actions, or a combination there of that collectively meets the relief
requirement. These curtailments are implemented during the next operating hour.
Transmission Operators are responsible for complying with TOP-007-WECC-1. When
flows exceed SOLs, the Western Interconnection reliability may be at risk. Compliance
with TOP-007-WECC-1 and other NERC reliability standards is most critical. IRO-006WECC-1, on the other hand, contains mandatory requirements for implementing the part
of the UFMP pertaining to curtailment of off-path schedules. Mandatory enforcement of
IRO-006-WECC-1 provides entities with the necessary motivation to curtail off-path
schedules and adjust generation to prevent and/or reduce qualified path overloads, thus
facilitating compliance with TOP-007-WECC-1. If implementing the UFMP, including
IRO-006-WECC-1, does not achieve the reduction in actual flow across a path, the TOP
is still obligated to take actions to reduce the actual flows to within SOLs in order to
comply with the requirements of TOP-007-WECC-1.

Questions on IRO-006-WECC-1

December 1, 2008
NERC appreciates the opportunity to work with WECC to clarify concerns with the
proposed IRO-006-WECC-1 standard. This standard is intended to replace the existing IRO-STD-006-1
standard approved by FERC. NERC staff has identified two main concerns with the IRO-006-WECC-1
standard.
Question 1:
NERC understands by way of explanation that WECC uses TOP-007-WECC-1 to manage the transfer path
power flow on the Major WECC Transfer Paths (using local and other relief procedures to ensure that power
flows do not exceed SOL for more than 30 minutes). NERC also understands that IRO-006-WECC-1 is used
to ensure that RC’s are responding to curtailment requests by the TOPs on six of these transfer paths. NERC
identified one path, Path Code 23, the APS Four Corners path that is not included in the list of Major Transfer
Paths. This would mean that TOP-007-WECC-1 does not apply to this path and as such the TOP is not
actively monitoring power flows and taking immediate action to relieve flow as to not exceed its SOL. Is there
a gap that needs to be filled for this transmission path? Is it correct to interpret that curtailments on the other
34 paths not covered under IRO-006-WECC-1 would not provide relief?
WECC Reply:
Due to the Bulk Electric System configuration in the Four Corners area, there is not a gap that needs to be
filled for this path. The Transmission Operator is responsible for managing each transfer path’s power flow.
If a Transmission Operator requests the curtailment of off-path schedules, Requirement 1 of IRO-006-WECC1 requires the Reliability Coordinator to approve or deny the request (please see document explaining the
Interactions between TOP-007 –WECC-1 and IRO-006-WECC-1 for further explanation). The RC’s
opportunity to deny the request is intended to prevent off-path schedule curtailments from causing other
reliability problems of which the TOP may not be aware. This refinement to the IRO-006-WECC-1 standard
aligns with the NERC functional model.
Path 23 is comprised of the 345/500 kV transformer at the Four Corners Substation. With all elements in
service at the Four Corners substation, the SOL from Four Corners to Arizona is defined by elements in Path
22, not the transformer comprising Path 23. Elements of Path 22 include the two Four Corners-Cholla 345kV
lines and the Four Corners-Moenkopi 500kV line. Flow across Path 23 is not significantly impacted by
unscheduled flow under normal system conditions, nor is it identified as one of the 40 major paths in TOP007-WECC-1. The only system condition for which Path 23 may require relief per the Unscheduled Flow
Mitigation Plan (UFMP) is when the Four Corners Generating Unit #5 is out of service. Unit #5 is connected
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to the 500kV bus. During instances when this generator is out of service, Path 23 then becomes a subset of
Path 22. The 345/500 kV transformer at the Four Corners Substation becomes one of Path 22’s limiting
elements and defines the Four Corners-Moenkopi 500 kV portion of the Path 22 SOL because it is now in
series with the Four Corners-Moenkopi 500 kV line. The Transmission Operator for Path 22 is still required
to comply with TOP-007-WECC-1. Therefore, there is no gap that needs to be filled for Path 23. In addition,
the Transmission Operator is required to comply with all other NERC and WECC reliability standards.
The Transmission Operators for the other 34 paths identified in TOP-007-WECC-1 may not request
unscheduled flow relief unless the Transmission Operators go through the process to qualify their paths per
the UFMP (see the qualification section of the UFMP). The Transmission Operators for these 34 paths will
use other local and WECC procedures to comply with the requirements of TOP-007-WECC-1.
Question 2:
The following is an excerpt taken from the UFAS Standard Drafting Team White Paper:
“In the proposed IRO-006-WECC-1 standard, responsibility for initiating schedule
curtailment is assigned to the Reliability Coordinators, and the responsibility for
implementing the curtailments is assigned to Balancing Authorities. The proposed
standard should improve the efficiency of the program including improved compliance,
more certain Unscheduled Flow relief, and fewer complications associated with multiple
entities taking partial responsibility for curtailment activity”
However, it is NERC’s interpretation that the proposed IRO-006-WECC-1 standard does not require the RCs
to initiate curtailments, but rather only respond to curtailment requests from the TOP. Based on previous
discussion regarding TOP-007-WECC-1, and our reading of IRO-006-WECC-1, it is our understanding that
the TOP initiates these schedule curtailments, not the RC. Is this correct? If not, please explain further (e.g.,
is this a function of the OATI webSAS tool, where the TOP makes the request but the RC actually “initiates”
the curtailment by confirming the request?).
WECC Reply:
Your understanding is correct. The RC does not actually initiate the curtailments, but rather, approves the
TOP’s request for curtailment(s). When a Transmission Operator submits a request to the RCs for off-path
schedule curtailments per the UFMP, the TOP submits those requests to the RC through the OATI webSAS
tool. Requirement 1 of IRO-006-WECC-1 requires the RC to approve or deny the request using the webSAS
tool. Unless the RC denies the request for reliability reasons, the webSAS tool, through preprogrammed
algorithms, identifies the off-path schedules to curtail and submits those curtailments to Balancing
Authorities, Purchasing Selling Entities, Generator Operators, and Transmission Operators identified on the
tags.
Secondly, what recourse does the TOP within WECC have if the RC denies the request for curtailment? Does
the TOP have a wide-area view through webSAS, such that they are aware of other options if their requests
are denied by an RC? If not, what steps would occur following the RC denial?
WECC Reply:

2

The RC has the wide-area view not the TOP. Transmission Operators are responsible for managing each
transfer path’s power flow and have several options per WECC’s procedures. When a Transmission
Operator requests the curtailment of off-path schedules, the Reliability Coordinator (RC) may deny the
request for reliability reasons. If the RC denies a curtailment request, the Transmission Operator in
coordination with the RC would then follow one of the other WECC or local procedures for reducing path
flow. The Transmission Operator is responsible for complying with all related NERC and WECC reliability
standards.
As discussed on the conference call on November 19, 2008 WECC will be preparing a paper that explains the
interaction between the TOP-007-WECC-1 and IRO-006-WECC-1 standards. In particular, the paper is to
include an explanation of the process flow of managing SOLs on the transfer paths in TOP-007-WECC-1 and
for mitigating unscheduled flow on transfer paths in IRO-006-WECC-1. NERC looks forward to the paper as
it may clarify these remaining concerns.
See attached White Paper addressing these topics.

3

Exhibit D
Standard Drafting Team Roster

Drafting Team IRO-STD-006
FIRST_NAME
Brenda
John
Paul
Tom
Ken
David
David
Phillip
Ken
Paul
Richard
Jaison
Curtis
Chuan-Hsier

LAST_NAME
Anderson
Cummings
Humberson
Isham
Wilson
Lemmons
Lunceford
O'Donnell
Otto
Rice
Salgo
Tsikirai
Winterfeld
Wu

COMPANY
Bonneville Power Administration
Northwestern Energy
Western Area Power Administration WACM
Arizona Public Service Company
WECC
Public Service Company of Colorado
California Independent System Operator
Sacramento Municipal Utility District
Western Area Power Administration
WECC
Sierra Pacific Resources, Inc.
PacifiCorp West
Deseret G&T
Los Angeles Department of Water and Power