Underfrequency Load Shedding Report

Jerry Rust

WECC

October 21, 2010

•NERC PRC-006-01

•WECC Consolidated Coordinated Plan

•Recommendations

Automatic Underfrequency Load Shedding – WECC Focus● Preserve the existing WECC Consolidated

Coordinated Plan - Variance

● Applicable to Correct Entity UFLS entities – responsible for the ownership,

operation, or control of UFLS equipment (WECC-0065 Criterion)

Automatic Underfrequency Load Shedding – WECC Focus● WECC Consolidated Coordinated UFLS Plan

13-page document posted for 30 days September 22, 2010 – closes October 22, 2010

Response to comments due back November 21, 2010

Is it complete? Did we miss something or miss-quote something?

Automatic Underfrequency Load Shedding – WECC Focus● Some issues within the approved standard may

cause WECC OC and PCC to re-think implementation M.E.B.12. Each Planning Coordinator shall have

dated evidence such as reports, data gathered from an historical event, or other dated documentation to show that it participated in a UFLS design assessment per Requirements E.B.12 and E.B.4 if UFLS program deficiencies are identified in E.B.11

Automatic Underfrequency Load Shedding – WECC Focus● E.B.11 Each Planning Coordinator in whose

area a BES islanding event results in system frequency excursions below the initializing set points of the UFLS program, shall participate in and document a coordinated event assessment with all affected Planning Coordinators to conduct and document an assessment of the event within one year of event actuation to evaluate: E.B.11.1. The performance of the UFLS equipment E.B.11.2. The effectiveness of the UFLS program

Automatic Underfrequency Load Shedding – WECC Focus● So what does this mean

Compare to the simulations that established the plan and determine if the actual event did not match the simulations – why? What is wrong? What changed? Etc.

Does WECC have the simulation model that establish the plan – in the past an ad-hoc group does the simulation analysis. It is maintained and updated? Is it an operating case with reflection of reserve?

Automatic Underfrequency Load Shedding – Recommendation● WECC form a permanent group to maintain the

simulation model and to be able to run a comparison analysis in the event it needs to be done. (maintain some kind of continuity of personnel) Reports to the JGC

Event Analysis has been under OC in the past

Automatic Underfrequency Load Shedding – Implementation● Effective one year following the first day of the

first calendar quarter after applicable regulatory approvals. January 1, 2011 anticipated date

● Finish WECC-0065

● Address where and whom to maintain simulation

Questions