WECC Criterion – TPL-000-WECC-CRT-3Page 1 of 15
Criterion Development Timeline
This section is maintained by the drafting team during the development of the document and will be removed when the document is approved by the WECC Board of Directors (Board).
Description of Current Draft
Current Status
This is the second posting for comment of WECC Criterion TPL-001-WECC-CRT-3, Transmission System Planning Performance.
Document Scope
This document is designed to address the substance of TPL-001-WECC-CRT-2.1 (TPL), Requirement WR3 and the requirements imposed by NERC TPL-001-4, Requirements R5 and R6. Standard Authorization Request (SAR) WECC-0100 also provides for review and disposition of Table W-1 associated with the WECC TPL. Once the Requirements of this document are more fully developed the drafting team will revisit the need to edit, modify, or delete the table.
Criterion as Proposed
The proposed criterion is designed to ensure the coordinated planning of the Western Interconnection under normal and abnormal conditions, and to ensure the availability of that planning information. This document applies to studies conducted in both the near-term and the long-term planning horizons.
Applicability
- Planning Coordinator
- Transmission Planner
Facilities
The document applies to:
- Bulk Electric System (BES) substation buses with specified exclusions.
- Studies conducted in both the near-term and the long-term planning horizons.
- Bulk-Electric System (BES) substations buses.
- Each of the following elements is specifically excluded from this Criterion:
- Line side series capacitor buses
- Line side reactor buses
- Shunt capacitor buses
- Shunt reactor buses
- Metering, fictitious, or other points of interconnection modeled solely for measuring electrical quantities; and,
- Other buses specifically excluded by each Planning Coordinator or Transmission Planner internal to their system.
Effective Date
An Effective Date for the proposed document is targeted for January 1, 2016, to coincide with the Effective Date of NERC Standard TPL-001-4, Transmission System Planning Performance Requirements.
Requirements and Measures
As stated.
Compliance
WECC Criteria do not have a Compliance section.
Procedural Background
On September 5, 2012, the WECC Board of Directors (Board) adopted a recommendation by the Regional Criteria Work Group (RCWG) changing the designation of this document from a WECC Criterion (CRT) to a WECC Regional Business Practice (RBP). On June 24, 2014, the Board reversed that decision and designated this document as a CRT.
In further keeping with the September 5, 2012 recommendation, on November 28, 2012, a Standard Authorization Request (SAR) was submitted to evaluate whether this document should be drafted as a WECC Regional Reliability Standard (RRS).
On December 19, 2012, the WECC Standards Committee (WSC) accepted the SAR as drafted with specific approval to assign an evaluation team to review the subject matter and return a recommendation to the WSC as to whether the document should be redrafted as an RRS.
On June 26, 2013, the WSC approved the evaluation team’s recommendation to ballot the retirement of TPL-001-WECC-RBP-2.1, WR1, WR2, WR4 and WR5. If approved the retirement would become effective coincident with the Effective Date of NERC’s TPL-001-4, because the content of the WECC Requirements will be resident in the NERC TPL-001-4.
On August 8, 2013, the WSC assigned the original drafting team, augmenting the team during later weeks.
On October 8, 2013, a WECC Ballot Pool voted to retire TPL-(012 through 014)-WECC-RBP-2.1, WR1, WR2, WR4 and WR5 of the Effective Date of NERC TPL-001-4. (The Effective Date is projected for approximately January 1, 2016. It should be noted that the TPL has a staggered Effective Date.)
On November 1, 2013, the WECC-0100 Drafting Team (DT):
- Reported completion of the tasks assigned in the WECC-0100 Standard Authorization Request (SAR);
- Requested the WECC Standards Committee (WSC) deem the WECC-0100 SAR complete; and,
- Requested the WSC accept the DT’s recommendation to proceed with informal drafting in support of an iterative SAR tailored to the remedial needs of TPL-001-WECC-RBP-2.1, System Performance, WR3 as well as a more granular implementation plan of TPL-001-4, Transmission System Planning Performance Requirements Requirement R5 and R6.
In light of the retirement of the TPL-001-WECC-RBP-2’s Requirements WR1, WR2, WR4 and WR5, the drafting team reported that an update of the associated Table W-1 was underway by the Reliability Subcommittee.
The WSC agreed to expand the WECC-0100 drafting team to include the entire Reliability Subcommittee, and accept the drafting team’s recommendation that further drafting continue on remedial language for:
- TPL-001-WECC-RBP-2.1. WR3;
- Table W-1; and,
- TPL-001-4, Requirements R5 and R6.
On December 5, 2013, the Board approved the decision to retire portions of the WECC TPL upon the Effective Date of the NERC TPL.
During June 2014, the Planning Coordinating Committee (PCC) conducted a straw poll concluding the most appropriate document categorization for this document should be that of a WECC Regional Criterion.
On June 24, 2014, the Board changed the designation of this document from that of a RBP to that of CRT.
Completed Actions / Date- SAR Filed.
- Review Team files Preliminary Recommendation.
- WSC approves ballot to retire WR1, WR2, WR4 and WR5.
- Notice of Joint Session to discuss retirement.
- Ballot Pool open asking for retirement of WR1, WR2, WR4 and WR5.
- WSC approves Drafting Team.
- Ballot Pool closed asking for retirement of WR1, WR2, WR4 and WR5.
- Joint Session to discuss retirement.
- Ballot open asking for retirement of WR1, WR2, WR4 and WR5.
- Drafting Team – First Meeting – Orientation.
- Ballot closed asking for retirement of WR1, WR2, WR4 and WR5. Retirement approved.
- Version 1 Posted – Open 45-Day Comment Period.
- Version 1 Posted – Closed.
Anticipated Actions / Date
- Version 2 Posted – Open 30-Day Comment Period
- Version 2 Posted – Closed
- Version 3 Posted – Open 30-Day Comment Period
- Version 3 Posted – Closed
- DT meets for final Comments / Forward to WSC
- WSC Meets
- Open Ballot Pool
- Joint Session – Notice
- Close Ballot Pool
- Joint Session
- Open Ballot
- Ballot Closed
- WSC Meets
- Notice to WECC Board of Directors
- Board
Implementation Plan
To Be Announced.
New or Modified Term(s) Used in the WECC Glossary for WECC Criteria and Naming Conventions (WECC Glossary).
This section includes all new or modified terms used in the proposed criterion that will be included in the WECC Glossary upon applicable approval. The new or revised terms listed below will be presented for approval with the proposed document. Upon WECC Board of Director (Board) adoption, this section will be removed and the approved terms will be moved to the WECC Glossary.
Term(s): None proposed
When this standard receives Board approval, the rationale boxes will be moved to the Supplemental Material Section of the standard.
A.Introduction
1.Title:Transmission System Planning Performance
2.Number:TPL-001-WECC-CRT-3
3.Purpose:To ensure the coordinated planning of the Western Interconnection under normal and abnormal conditions, and to ensure the availability of that planning information.
4.Applicability:
4.1.Functional Entities:
4.1.1.Planning Coordinator
4.1.2.Transmission Planner
4.2.Facilities:
4.2.1.This document applies to studies conducted in both the near-term and the long-term planning horizons.
4.2.2.This document applies only to Bulk-Electric System (BES) substations buses.
4.2.3.Each of the following elements is specifically excluded from this Criterion:
4.2.3.1.Line side series capacitor buses
4.2.3.2.Line side reactor buses
4.2.3.3.Shunt capacitor buses
4.2.3.4.Shunt reactor buses
4.2.3.5.Metering, fictitious, or other points of interconnection modeled solely for measuring electrical quantities; and,
4.2.3.6.Other buses specifically excluded by each Planning Coordinator or Transmission Planner internal to their system.
5.Effective Date:The first day of the first quarter following WECC Board of Director approval, but in no case earlier than the Effective Date of NERC Standard TPL-001-4, Transmission System Planning Performance requirements.
6.Background:
(Optional)
B.Requirements and Measures
Rationale for Requirement WR1:Requirement WR1 recognizes that each system has its own unique characteristics that need to be addressed. Rather than lock each entity to a specific study parameter this Requirement sets a basal study parameter coupled with a unique nominal value, established by the Transmission Planner and the Planning Coordinator, to be used in the absence of either a more stringent or less stringent study parameter.
In the context of this document the word “nominal” carries its common definition and is the base voltage used in the entity’s Planning Assessment model. This voltage will vary from entity to entity.
Requirement WR1 does not preclude an entity from using either a more stringent or less stringent criteria. However, when an entity uses a study criteria other than that required in requirement WR1, it must make available the associated Planning Assessment showing the assumptions used (see later Requirement).
WR1. Each Transmission Planner and Planning Coordinator shall use the following basal criteria in its Planning Assessment, unless otherwise specified in accordance with Requirements WR2 and WR3: [Addresses NERC TPL R5 and R6]
1.1.Steady-state voltages at all applicable Bulk-Electric System (BES) buses shall stay within each of the following limits:
1.1.1.95 percent to 110 percent of the nominal customer requirement.
1.1.2.90 percent to 110 percent of the nominal equipment protection level.
Rationale for Requirement WR1.2:Requirement WR1.2 establishes a target that could be met by each entity without incurring costs that would outweigh the benefits. Many legacy systems were not designed to meet a more stringent threshold. The eight percent target of Requirement WR1.2 is established not by a technical study; rather, it is established based on sound engineering judgment. Further, certain entities are bound by state tariffs that establish the percentage rate specifically at eight percent.
By default, only automatic post-contingency actions including capacity or reactor switching are considered when calculating voltage deviation.
Where the Transmission Planner or the Planning Coordinator apply less stringent criteria when studying their own systems, the less stringent criteria would be permissible so long as other Transmission Planners and Planning Coordinators were also allowed to apply the same less stringent criteria to their own systems. For example, if an entity applied manual capacitor or reactor switching to its own system the same criteria would be allowed for the systems of others. By contrast, where the Transmission Planner or the Planning Coordinator apply more stringent criteria to their own systems, that Transmission Planner or Planning Coordinator would not be allowed to impose the more stringent criteria on any system other than its own.
1.2.Post-Contingency steady-state low voltage deviation at each applicable BES bus serving load (having no intermediate connection) shall not exceed eight percent for P1 events. [Addressing TPL R5]
1.3.Transient stability voltage response shall be verified by demonstrating that for all P1-P7 category events, the transient voltage response at applicable BES buses shall recover to 80 percent of pre-contingency voltage within 10 seconds of the initiating event.
Rationale for Requirement WR1.4:For purposes of Requirement WR1.4, positive damping in stability analysis is demonstrated by showing that the amplitude of power angle or voltage magnitude oscillations after a minimum of 10 seconds is less than the initial post-contingency amplitude. In any case, results that do not show positive damping within a 30-second time frame shall be deemed undamped.
Requirement 1.4 is not intended to require that transient stability simulations be run out to 30-seconds all the time in order to ensure the system is stable and positively damped. Shorter runs are permissible.
1.4.Oscillations that do not show positive damping within a 30-second time frame shall be deemed undamped.
WM1. TBD
Rationale for Requirement WR2:The rationale for Requirement WR2 is to clarify that an entity may apply more stringent criteria to its own system; however, it may not impose more stringent criteria on any other entity or system.
WR2. Each Transmission Planner and Planning Coordinator that uses more stringent criteria in its Planning Assessment than that stated in Requirement WR1 shall apply that criteria only to its own system.
WM2. TBA
Rationale for Requirement WR3:The rationale for requirement WR3 is to ensure that where study criteria different from that required in Requirement WR1 is used, the study criteria are made available to any entity in need of it. The intent of the requirement is not to mandate “how” that information is published or exchanged – only that it be made available. “How” the information is exchanged is business function left open to the affected entities.
WR3. Each Transmission Planner and Planning Coordinator that uses study criteria different from the basal criteria in Requirement WR1 shall make its Planning Assessment available upon request.
WM3. TBA
Rationale for Requirement WR4:Requirement WR4 is designed to establish precautionary markers that when discovered warrant investigation. The Requirement is not intended to infer that the presence of any one of more of the bulleted conditions creates a de facto negative impact on reliability.
The term “cascading” in Requirement WR4 is not used as the NERC defined term “Cascading.”
WR4. Each Transmission Planner and Planning Coordinator shall investigate for cascading and uncontrolled islanding, if any of the following indicators is observed in its Planning Assessment studies: [Addresses TPL R6]:
- Thermal overload on a Facility exceeds the phase protective relay settings described in NERC PRC-023-3, Transmission Relay Loadability, and trips.
- The transient voltage response at any BES bus outside of the criteria defined in Requirement [WR XXXX - THIS CRITERIA IS YET TO BE DEFINED] of this document, h
WM4. TBD
Rationale for Requirement WR5:Requirement WR5 is intended to ensure voltage stability of transfer paths as well as the system as a whole, at peak load conditions. A margin on real power flow is used as a test for voltage stability.
WR5. Each Transmission Planner and Planning Coordinator shall identify voltage stability by maintaining positive reactive power margin demonstrated by the following criteria. Power flow solutions refer to post contingency conditions but only the actions of automatic devices should be modeled:
5.1For all P0-P1 events a power flow solution shall be reached at a minimum of 105 percent of transfer path flow.
5.2For all P0-P1 events a power flow solution shall be reached at a minimum of 105 percent of forecasted peak load.
5.3For all P2-P7 events a power flow solution shall be reached at a minimum of 102.5 percent of transfer path flow.
5.4For all P2-P7 events a power flow solution shall be reached at a minimum of 102.5 percent of forecasted peak load.
WM5. TBD
Version History
1 / March 6, 2008 / WECC Planning Coordination Committee (PCC) approved TPL-(001 thru 004)-WECC-1-CR. / Reliability Subcommittee translates existing WECC components of NERC/WECC Planning Standards into a CRT.
1 / April 16, 2008 / WECC Board of Directors (Board) approved / No substantive changes
2 / October 13, 2011 / PCC approves / Clarifies “corridor”
2 / December 1, 2011 / Board approves / No substantive change
2 / September 5, 2012 / Board approves / Approved a nomenclature change from “CRT” to “RBP”
2.1 / August 6, 2013 / Errata / WM2 Measure moved to WM3. WM3 Measure moved to WM4. WM4 Measure moved to WM2.
2.1 / December 5, 2013 / Board approves / On October 8, 2013, the Ballot Pool voted to retire WR1, WR2, WR4 and WR5 of TPL-(012 through 014)-WECC-RBP-2 as of the Effective Date of NERC TPL-001-4. On December 5, 2013, the Board ratified that decision.
2.1 / June 24, 2014 / Board changed the RBP designation to that of CRT / No substantive change, only designation.
3 / Pending
Disclaimer
WECC receives data used in its analyses from a wide variety of sources. WECC strives to source its data from reliable entities and undertakes reasonable efforts to validate the accuracy of the data used. WECC believes the data contained herein and used in its analyses is accurate and reliable. However, WECC disclaims any and all representations, guarantees, warranties, and liability for the information contained herein and any use thereof. Persons who use and rely on the information contained herein do so at their own risk.
Attachments
- TBD
Rationale
During development of this document, text boxes were embedded within the body to explain the rationale for various parts of the standard. Upon Board approval, the text from the rationale text boxes will be moved to this section.
Western Electricity Coordinating Council