2 PRC-006-WECC-CRT-1 Purpose of UFLS Background Current Situation Purpose of PRC-006-WECC-CRT-1Proposed CriteriaImplementationNext Steps
3 PRC-006-WECC-CRT-1Last automatic protection scheme to arrest the frequency decline after a disturbanceLoad Shedding Occurs;Frequency decline was arrested; and,Recovery was observed.
4 Background - PRC-006-WECC-CRT-1 July 2 & 3, 1996 and August 10, 1996 Western Interconnection wide disturbancesWECC Disturbance ReportComplete review of the Underfrequency load shedding programsCoordination with generator off-nominal frequency protection requirementsCoordination of automatic and manual load restorationCoordination between and within sub-regions of the Western Interconnection
5 Background - PRC-006-WECC-CRT-1 November 8, 1996 ad hoc Underfrequency Issues Work Group (UIWG) formedDetermine if a uniform UFLS program can be specified for all of WECCIf yes, recommend a uniform off-nominal frequency programRecommend a policy regarding the automatic restoration of loadRecommend a policy regarding intentional tripping of tie lines and generators due to underfrequency
6 WECC 2009 Goals for UFLSThe Western Electricity Coordinating Council Operating and Planning Committees have established a joint goal to review the effectiveness of the design and implementation of the WECC Coordinated Off-Nominal Frequency Load Shedding and Restoration Program
7 WECC 2009 Goals for UFLS WECC UFLS – Test Effectiveness Review of frequency set pointsReview of Generator tripping set pointsReview of Automatic RestorationAddress the NERC registered entities – Correct Entities and inventoryConsistent with PRC standards – Gen StandardsAddress Variable GenerationFull and detailed documentationSouthern Island Load Tripping PlanNWPP UFLS PlanOthers
8 WECC 2009 Approach for UFLS Inventory Topology (variable generation) SimulateVarious CasesSolve for Worst Case ContingencyRecommended Changes if Necessary
9 WECC 2009 Time-Frame for UFLS Findings October 2009Changes if NecessaryRecommendations October 2009Full and detailed documented Plan – First quarter 2010 (if not sooner)
10 WECC 2009 Findings for UFLSOver 200 simulations utilizing the existing inventory of relay and associated armed load verifies the following:Load Shedding Occurs;Frequency decline was arrested; and,Recovery was observed.The WECC plans still performed under simulation as originally designed.
11 Purpose - PRC-006-WECC-CRT-1 NERC PRC is categorized as a fill-in-the-blank standard. The WECC Board of Directors has instructed WECC to utilize the Process for Developing and Approving WECC Standards whenever drafting criteria to meet NERC fill-in-the-blank requirements and to categorize the resultant work product as a criterion under the WECC Document Categorization procedures.
12 Goals - PRC-006-WECC-CRT-1 No Changes to Existing PlanConsolidate the Existing PlanDefine how to implement Existing PlanDevelop timelines to NERC requirementsDefine responsible entities
13 Consolidation - PRC-006-WECC-CRT-1 WECC Coordinated Plan - consolidated 12 pages, approved 1st quarter 2011 by the OC and PCC, approved by WECC Board of Directors 2nd quarter 2011WECC Coordinated Plan recognizes sub-plans, such as NWPP and SILTNo changes to the existing plan
14 Consolidation - PRC-006-WECC-CRT-1 WECC Coordinated Plan first level of underfrequency load shedding occurs at 59.5 Hz (SILT) next at 59.3 Hz (NWPP) and then 59.1 Hz (the remaining WECC)WECC Coordinated Plan may be changed in accordance with WECC processWECC Coordinated Plan currently meets NERC Reliability Standards
15 PRC-006-WECC-CRT-1The WECC JGC established the requirement for a UFLS “Review Group”A joint regional group comprised of WECC Balancing Authorities, Planning Coordinators, Transmission Operators, and Transmission Planners created by the WECC Joint Guidance Committee to review and maintain an accurate underfrequency load shedding database and simulation models reflecting the WECC Off-Nominal Frequency Load Shedding Plan.WECC Review Group to receive the required information and assure WECC Coordinated Plan performs under simulation as designed
16 PRC-006-WECC-CRT-1Underfrequency load shedding entities (UFLS Entities) shall mean all entities that are responsible for the ownership, operation, or control of UFLS equipment as required by the Coordinated Plan. Such entities may include one or more of the following:Transmission OwnerDistribution Provider
17 PRC-006-WECC-CRT-1BA peak load is armed in accordance with WECC Coordinated PlanBA to allocate its historical peak load to TOPsTOPs must identify which sub-area Coordinated Plan they are following (e.g. NWPP, SILT, or WECC)TOPs or its agent to coordinate with UFLS Entities to assure underfrequency relays are in place and armed in accordance with the WECC Coordinated Plan
18 PRC-006-WECC-CRT-1The criterion allows for flexibility of various combinations of the UFLS Entities to meet the requirements and fulfill the WECC Coordinated Plan
19 PRC-006-WECC-CRT-1Each Transmission Operator or its agent shall produce documentation showing how it coordinated implementation of each sub-area Coordinated Plan of the Coordinated Plan with its UFLS Entities. Documentation may include, but is not limited to, evidence of how the adopted sub-area Coordinated Plan of the Coordinated Plan is implemented among the TOP and the UFLS Entities.
20 PRC-006-WECC-CRT-1Each UFLS Entity or its agent shall coordinate and provide documentation of its responsibilities in meeting the Coordinated Plan to the Review Group. Documentation shall include:A listing of its responsibilities as required under the Coordinated Plan.A designation of the agent responsible for all data submission to demonstrate compliance with the Coordinated Plan
21 PRC-006-WECC-CRT-1Each UFLS Entity or its agent shall compile their respective Coordinated Plan data and dynamics file in the WECC-defined format, as listed in the Coordinated Plan – Data Submittals Requirements (Attachment B of this criterion), for its entire load and annually, by June 1, submit Attachment B to the Review Group and to the UFLS Entity’s respective Transmission Operator.
22 PRC-006-WECC-CRT-1Each Generator Owner shall annually compile and submit to the Review Group, no later than June 1, their respective Coordinated Plan data and dynamics file for its generation, in the format defined in Attachment B of this criterion.
23 PRC-006-WECC-CRT-1The Review Group to coordinate and perform all post-event analyses associated with the Coordinated Plan.
24 Time-Frame PRC-006-WECC-CRT-1 It is anticipated that this document will be ready for WECC standing committee and Board of Director approval in time to be effective on January 1, If the necessary approvals are received in time for an effective date of January 1, 2012, the following dates will be enforced:Balancing Authority shall meet R5 for the first time on June 1, 2012UFLS Entities shall meet R9 for the first time on June 1, 2012.
25 Time-Frame PRC-006-WECC-CRT-1 Generator Owners will meet R12 for the first time on June 1, 2012.The Review Group will complete the first annual review of the Coordinated Plan by November 1, 2012.If the necessary approvals are not obtained in time for this criterion to become effective on January 1, 2012, then the dates above will be incremented to 2013.