UNITED STATES OF AMERICA
BEFORE THE
FEDERAL ENERGY REGULATORY COMMISSION
Transmission Planning Reliability Standards)Docket No. RM12-1-000
JOINT COMMENTS OF ELECTRIC RELIABILITY COUNCIL OF TEXAS, INC.; ISO
NEW ENGLAND INC.; MIDWEST INDEPENDENT TRANSMISSION SYSTEM OPERATOR, INC.; NEW YORK INDEPENDENT SYSTEM OPERATOR, INC.; PJM
INTERCONNECTION, L.L.C.; AND SOUTHWEST POWER POOL, INC.
I.INTRODUCTION
The Electric Reliability Council Of Texas, Inc.; ISO New England Inc.; Midwest
Independent Transmission System Operator, Inc.; New York Independent System Operator, Inc.;
PJM Interconnection, L.L.C.; and Southwest Power Pool, Inc. (“Joint ISO/RTO Commenters”)
respectfully submit these joint comments in response to the Commission’s Notice of Proposed
Rulemaking (“NOPR”) issued by the Federal Energy Regulatory Commission (the
“Commission”) in the above-captioned docket on April 19, 2012.1
As discussed in the NOPR, the North American Electric Reliability Corporation
(“NERC”), the Commission-certified Electric Reliability Organization (“ERO”), has petitioned
for approval of the modified Transmission Planning Reliability Standard, TPL-001-2
(Transmission System Planning Performance Requirements), which combines four currently
effective TPL Reliability Standards, TPL-001-1, TPL-002-1b, TPL-003-1a, and TPL-004-1, into
a single standard. NERC has also requested retirement of the currently effective TPL standards.
Pursuant to Section 215(d) of the Federal Power Act, the Commission proposes to remand
proposed Reliability Standard, TPL-001-2, due to the inclusion therein (as Footnote 12 to Table
1 Transmission Planning Reliability Standards, Notice of Proposed Rulemaking, 139 FERC ¶ 61,059 (2012).
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1, addressing Steady State and Stability Performance Extreme Events) of a provision that would allow a transmission planner to plan for non-consequential load loss following a single
contingency, provided that the plan is documented and vetted in an open and transparent
stakeholder process.
Specifically, the NOPR indicates the Commission’s belief that this provision is “vague and unenforceable because it does not adequately define the circumstance in which an entity can plan for non-consequential load loss following a single contingency.”2 On that basis, the
Commission proposes to find that proposed TPL-001-2 “does not meet the statutory criteria for approval that a mandatory Reliability Standard must be just, reasonable, not unduly
discriminatory or preferential, and in the public interest.”3
Beyond this, the Commission agreed that the proposed standard “includes specific
improvements over the currently effective Transmission Planning Reliability Standards and…is responsive to certain Commission directives.”4 Accordingly, notwithstanding the remand, the
Commission:
seeks comments from the ERO and other interested persons regarding the
following important reliability issues to ensure that the proposed Reliability
Standards adequately maintains reliability and that the directives have been met:
(a) Planned Maintenance Outages, (b) Violation Risk Factors, (c) Protection
System Failures versus Relay Failures, (d) Assessment of Backup or Redundant
Protection Systems, (e) Single Line to Ground Faults, and (f) Order No. 693
Directives.5
2 NOPR at P 1. See also NOPR at P 13.
3 Id.
4 NOPR at P 2. See also NOPR at P 15.
5 NOPR at P 15.
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II.COMMENTS
In addition to expressing its views on the proposed remand, the Joint ISO/RTO Commenters offer comments on five of the areas addressed in the NOPR:
(A) Violation Risk Factors;
(B) Protection System Failures versus Relay Failures;
(C) Assessment of Backup or Redundant Protection Systems;
(D) P5 Single Line to Ground Faults; and
(E) Order No. 693 Directives.
By way of background, the Joint ISO/RTO Commenters are registered NERC Planning Entities and would be subject to the requirements of the TPL-001-2 reliability standard. The s generally agrees with the Commission’s proposed remand of the Reliability Standard based on present interpretation of Footnote 12 of Exhibit 1 and its continuation from Footnote “b” of existing TPL Standards 001-004. Until NERC has resolved those issues with the Footnote “b” requirement, Footnote 12 will not be acceptable.
Substantively, the Joint ISO/RTO Commenters do not support transmission planning for
planned or controlled interruption of non-consequential firm load following loss of a single
transmission facility. The original footnote b was included in the standards to address unusual
system circumstances, such as where generation and load comprise a local area network, or
where such generation and load are remotely positioned and supported by limited and costly
transmission ties to a more robust grid. In such circumstances - where the loss of one element of
the supporting tie could result in inability to serve all of the load in the local area network - it
may be reasonable to base decisions regarding the acceptability of such load loss on the
likelihood of the event relative to the high cost of remedial action. However, the standard and its
various revisions have never sufficiently specified the nature of such circumstances because of
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the inherent difficulty in doing so. As a result, confusion has arisen about the characteristics of the n-1 events for which loss of firm load is acceptable.
The Joint ISO/RTO Commenters believe that perpetuating this confusion can result in
degradation of levels of load service reliability below what should be reasonably expected by
customers of the Bulk Electric System. Further, the Joint ISO/RTO Commenters do not believe
that in the vast majority of circumstances, routinely planning for supply to firm loads for all n-1
events will cause transmission investment that is disproportionate to service-level benefits.
For these reasons, the Joint ISO/RTO Commenters propose that the Commission either require the elimination of Footnote 12 from the Reliability Standard or modify it to allow its use only in conjunction with a petition to FERC to waive (on an exception basis) the requirement to maintain firm load service for a specifically identified system configuration issue warranting
Footnote 12’s application.
A.Violation Risk Factors
The Commission seeks comment on why Requirement R1 of proposed Reliability
Standard TPL-001-2 carries a VRF of “Medium” while Requirement R1 of the currently
effective Reliability Standard TPL-001-0 carries a VRF of “High.”6 The new Requirement R1 of
the proposed TPL-001-2 relates to model maintenance, a necessary condition to being able to
perform an assessment, which is a different matter from the current Requirement R1.
Requirement R1 of the currently effective standard, relating to performing an assessment,
corresponds to Requirement R2 of the proposed standard, both of which carry a VRF of “High”
Thus, the Joint ISO/RTO Commenters understand that the VRF is different for the new
Requirement R1 because it is a different requirement from the current Requirement R1.
6 NOPR at PP 20-23.
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The Commission also seeks clarification why the VRF level assigned to Requirement R6
is “Low,” since it appears that Requirement R6 requires more than a purely administrative task.7
Prior to commencing the planning assessment, the Planning Coordinator and Transmission
Planner must determine as matter of policy and practice the criteria or method that will be used
to identify unstable conditions from the simulation results. Given that this would be done
outside of the planning assessment, the Joint ISO/RTO Commenters believe that defining and
documenting within the assessment is essentially an administrative task, suitable to the “Low”
VRF level assigned.
B. Protection System Failures versus Relay Failures
The NOPR provides the following background regarding this issue from the NERC
petition:
NERC states that its modification to the planning contingency categories in Table
1 of the proposed standard is intended to add clarity and consistency regarding
how a delayed fault clearing will be modeled in planning studies. NERC states
that the basic elements of any protection system design involve inputs (i.e.,
current and D/C and A/C voltage) to protective relays and outputs (i.e., trip
signals, close signals, and alarms) from protective relays and that reliability issues
associated with improper clearing of a fault on the bulk electric system can result
from the failure of hundreds of individual protection system components in a
substation. However, NERC believes that while the population of components
that could fail and result in improper clearing is large, that population can be
reduced dramatically by eliminating those components which share failure modes
with other components. NERC states that the critical components in protection
systems are the protective relays themselves, and a failure of a non-redundant
protective relay will often result in undesired consequences during a fault.
According to NERC, other protection system components related to the protective
relay could fail and lead to a bulk electric system issue, but the event that would
be studied is identical, from both transient and steady state perspectives, to the
event resulting from a protective relay failure if an adequate population of
protective relays is considered.8
7 NOPR at PP 24-26.
8 NOPR at P 27 (footnote omitted).
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In response to NERC’s explanation, the Commission observes that as-built designs are not standardized and the most critical component failure may not always be the relay.”9
Accordingly, the NOPR solicits comments on whether the provisions of the proposed Reliability Standard relating to the study of multiple contingencies “limit[] the planners’ assessment of a
protection system failure because it only includes the contingency of a faulty relay
component.”10 The Commission also seeks comments on whether the relay may not always be the larger contingency, and how the loss of protection system components that may be integral to multiple protection systems impacts reliability.11
The Joint ISO/RTO Commenters agree with the Commission that the range of potential
assessment should be expanded to include all components of a protection system including
instrument transformers, protective relays, auxiliary relays and communications systems for the
purpose of Category P-5 contingencies. However, as these devices are often in series,
consideration of all of these components will not necessarily have any significant impact on
analyses. This will typically require only one “failure to trip” contingency per protective zone to
cover the failure of any component with the associated protection system, but could introduce
additional contingencies to cover “failure to block tripping” (e.g., communications failure on
directional comparison blocking scheme, etc.). With regard to DC power supply (i.e., batteries),
complete failure of the DC power supply in conjunction with a short-circuit fault should be
considered an extreme event, so long as there is remote monitoring and/or alarming on the DC
voltage.
9 NOPR at P 31.
10 NOPR at P 33.
11 Id.
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C.Assessment of Backup or Redundant Protection Systems
As summarized in the NOPR, NERC’s petition explains that proposed Reliability
Standard TPL-001-2, Requirement R3, Part 3.3.1 and Requirement R4, Part 4.3.1 “require that
simulations faithfully duplicate what will happen in an actual power system based on the
expected performance of the protection systems[, so that] if a protection simulation is designed
‘to remove multiple Elements from service for an event that the simulation will be run with all of
those Elements removed from service.’”12 The Commission notes that the current standard
(Reliability Standard TPL-003-0, Requirement R1.3.10) provides that a planner must “include
the effects of existing and planned protection systems, including any backup or redundant
systems in its planning assessment.”13 The Commission finds, however, that the proposed
standard does not explicitly refer to backup or redundant systems, and therefore seeks
clarification from the ERO “whether the proposed Requirements address all protection systems,
including backup and redundant protection systems that can have an impact on the performance
of the bulk electric system.”14
Pertinent to this point, the Joint ISO/RTO Commenters believe that if a protection system is not fully redundant, then contingencies should be studied under Category P5 to simulate both delayed clearing and operation of remote backup protection to trip additional facilities when required. If a protection system is fully redundant, that is, if a single failure of any component in the protection system (other than monitored DC voltage) would not result in delayed tripping, failure to trip, failure to block tripping or any other kind of over tripping, then it should not be necessary to analyze protection system failure under Category P5.
12 NOPR at P 34.
13 NOPR at P 35 (emphasis added).
14 NOPR at P 36.
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D.P5 Single Line to Ground Faults
The NOPR states that Table 1 of the proposed Reliability Standard TPL-001-2 identifies
the initiating contingencies that must be evaluated to ensure that the planned system meets the
performance requirements.15 The proposed modifications to Table 1 would change the
classification of events and fault types, clarify events and fault types, and remove the ambiguity
of performance requirements. The Commission seeks clarification whether “fault types” in
Table 1 of the proposed Reliability Standard “refers to the initiating event or initiating fault for
the contingency rather than the type of fault into which the initiating fault may evolve, and how
the clarification is consistent with the simulations being representative of what will occur in real-
time.”16
The Joint ISO/RTO Commenters believe that the possibility of the fault described in P5
evolving into a three-phase fault is already covered as an extreme contingency, so the inclusion
of this possibility in P5 would require an extreme contingency to meet normal contingency
performance requirements. Therefore, the current “fault types” in Table 1 are appropriate.
E.Order No. 693 Directives
The Commission seeks clarification and comment on certain Order No. 693 directives.
1.Peer Review of Planning Assessments
In Order No. 693, the Commission stated that “it sees no reason why peer reviews should
not be part of a Reliability Standard since TPL-001-0 through TPL-004-0 already include . . . a
review of assessment by the associated regional reliability organization.”17 In the NOPR, the
Commission seeks clarification on how the NERC proposal ensures the early input of peers into
15 NOPR at P 37.
16 NOPR at PP 37-38.
17 NOPR at P 40, quoting Order No. 693, FERC Stats. & Regs. ¶ 31,242 a P 1755.
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the planning assessments or any type of coordination amongst peers will occur, on whether and how there is a sufficient level of evaluation and ability to provide feedback to planners, and on whether Requirement R8 requires input on comments to be included in assessment.18
The Joint ISO/RTO Commenters recommend that the requirement for peer review of
planning assessments be revised to reflect that a response is required only to comments on a final
Planning Assessment, and not to comments on drafts developed during the analysis process.
Requiring formal responses on all drafts would be cumbersome and unworkable, and is not
necessary to provide commenters the opportunity to provide input. Moreover, to recognize the
time limitations involved in conducting assessments, there should also be a limit on the comment
period. Formal comments should be submitted within 90 days of receipt of the assessment, and
planning coordinators should have 90 days from the date of receipt to provide written responses
to those comments.
2.Spare Equipment Strategy
In Order No. 693, the Commission directed NERC to develop a modification “to require assessments of outages of critical long lead-time equipment, consistent with the entity’s spare equipment strategy.”19 In the NOPR, the Commission notes that NERC’s spare equipment
strategy appears limited to steady-state analysis, and seeks clarification why stability analysis conditions were excluded from the spare equipment strategy.20
The Joint ISO/RTO Commenters believe that stability analyses comparable to steady-
state analyses required under Requirement 2.1.5 as a result of spare equipment strategy would
not produce significant benefits justifying the extra analysis burden, because stability analysis
18 NOPR at 42.
19 NOPR at P 43, quoting Order No. 693, FERC Stats. & Regs. ¶ 31,242 at P 1786.
20 NOPR at P 44.
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already required under Category P6 will produce more definitive tests of longer-term equipment unavailability.
3.Assessments and Documentation
a.Dynamic Load Models
In Order No. 693, the Commission directed “the ERO to modify the Reliability Standards
to require documentation of load models used in system studies and the supporting rationale for
their use.”21 The Commission seeks clarification whether the documentation of dynamic load
models used in system studies and the supporting rationale for their use under Requirement 2.4,
Part 2.4.1, will be included in the documented assumptions under Requirement R2.22 The Joint
ISO/RTO Commenters have not uniformly determined a need to model dynamic loads, and
therefore have not benchmarked any such models.
The Joint ISO/RTO Commenters recommend that prior to the implementation of
Requirement 2.4, Part 2.4.1, a modeling standard should exist that is specific to dynamic load models. Such a modeling standard (MOD) could require documentation of the models and the supporting rationale for their use.
b.Footnote “a”
In Order No. 693, the Commission directed NERC to modify “footnote (a) of Table 1
with regard to applicability of emergency rating and consistency of normal ratings and voltages
with values obtained from other reliability standards.”23 The Commission seeks comment on
whether normal facility ratings align with FAC-008-1 and normal voltage ratings align with
21 NOPR at P 50, quoting Order 693, FERC Stats & Regs. ¶ 31,242, at P 1789.
22 NOPR at P 50.
23 NOPR at P 53, quoting Order No. 693.
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VAR-001-1, and on whether facility ratings used in planning assessments align with other reliability standards.
As a general matter, the Joint ISO/RTO Commenters note that because transmission
facility thermal ratings are typically calculated only for time periods of minutes or more, there
are generally no applicable emergency thermal ratings that would be valid in the shorter
timeframe of a stability simulation. However, observation of facility trip ratings (i.e., relay trip
ratings) are valid in the stability simulation time frame, and should be considered if associated
protective relay schemes are sensitive to power swings (e.g., impedance relays with no out-of-
step trip blocking for stable swings, etc.). Accordingly, the Joint ISO/RTO Commenters believe
that there is no reason to include a requirement to observe thermal facility ratings in stability
studies, but also believes that facility trip ratings should be observed in stability studies.
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III.CONCLUSION
The Joint ISO/RTO Commenters request the Commission to act on the NOPR in a
manner consistent with these comments.
Respectfully submitted,
Matthew Morais*Carl F. Patka*
Assistant General CounselAssistant General Counsel
Electric Reliability Council of Texas, Inc.Raymond A. Stalter
2705 West Lake DriveDirector of Regulatory Affairs
Taylor, Texas 76574New York Independent System Operator,
mmorais@ercot.comInc.
10 Krey Blvd
Rensselaer, New York 12144
cpatka@nyiso.com
Raymond W. HepperCraig Glazer*
Vice President, General Counsel, and SecretaryVice President-Federal Government Policy
Theodore J. Paradise*PJM Interconnection, L.L.C.
Assistant General Counsel, Operations andSuite 600
Planning1200 G Street, N.W.
ISO New England Inc.Washington, D.C. 20005
One Sullivan Road202-423-4743
Holyoke, Massachusetts 01040glazec@pjm.com
tparadise@iso-ne.com
Stephen G. Kozey*Paul Suskie*
Vice President, General Counsel, andSenior Vice President, Regulatory Policy and
SecretaryGeneral Counsel
Midwest Independent Transmission SystemSouthwest Power Pool, Inc.
Operator, Inc.415 North McKinley, Suite 140
P.O. Box 4202Little Rock, Arkansas 72205
Carmel, Indiana 46082-4202psuskie@spp.org
skozey@midwestiso.org
* = persons designated to receive service
Date: July 20, 2012
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