Presentation on theme: "WECC Planning Committee Underfrequency Load Shedding Review Group Update March 25, & 26, 2014."— Presentation transcript:
1WECC Planning Committee Underfrequency Load Shedding Review Group Update March 25, & 26, 2014
2UFLSRG Underfrequency Load Shedding Review Group (UFLSRG) Philip Augustin Richard Hydzik Jerry RustKent Bolton Danny Johnson Hari SinghDesmond Chan Gerald Keenan Dede SubaktiEleanor Ewry Stephanie Lu Branden SudduthRoy Gearhart Grace Martinez Shilpa ToppoIrina Green Chris Pink Mike VanRemoortereMark Hanson Steve Rueckert Gregory Vassallo
3After a disturbance – loss of generation - what happens? Devices respond to a frequency changeFrequency sensitive load – motorsFrequency sensitive generation – governorsAutomatic Generation control – AGCContingency Reserve Deployment – generation, curtailment interruptible load, etc.Other measures
4Typical WECC Frequency Excursion *07/16/96Typical WECC Frequency ExcursionPoint APoint BPoint CSeconds*4
5After a disturbance – loss of generation - what happens? If frequency is still declining then what?
6Purpose of UFLSLast automatic protection scheme to arrest the frequency decline after a disturbanceLoad Shedding Occurs;Frequency decline was arrested; and,Recovery was observed.
7UFLSRG Concepts to Remember UFLS Plan is to protect against cascading resource lossWECC RAS 1 is a separation Scheme –COI and Four CornersNorth IslandSouth Island
8UFLSRG PRC-006-1 Broken down into these Requirements Joint review including historical events - E.B.1Identified Island – E.B.2A Regional UFLS Plan & simulation - E.B.R3. through R5.Adopted by the WECC BoardA Regional UFLS Data Base – R6. thru R9.Established through PRC-006-WECC-CRT-1
9UFLSRGSimulation of the Plan Once every 5 years - By November 1, 2014 (first year) – E.B.4UFLSRG Identified Islands and Scenarios E.B.1 & E.B.2 based upon prior simulations and Southwest Outage14 different scenarios
10UFLSRG Simulation and Report Findings WECC technical review and formatting – will be posted for review – approval at July meetingsPerformance of the various UFLS settings demonstrated the applied relays will provide adequate protection for the resource losses totaling up to 25% or greater in the defined islandsFrequency excursion will experience conditions that would have 58.0Hz encroached but not passedStudies illustrated that the frequency arrestment utilized the full 5-step load shed and resulted in acceptable trajectory for frequency recoveryIn some cases, a few of the island configurations are showing 15-seconds anti-stalling features being engaged.
11UFLSRG Islands Simulated WECC North Island (Canada, further separation Alberta)South IslandSW Outage event and all combinations
12UFLSRG 59.5 SILT ----- (~3,200 MW) 59.3 NW 5.6% 59.2 NW 5.6% 2014 current WECC PlanSILT (~3,200 MW)NW %NW %WECC other %NW %WECC other %NW %WECC other 6.3%NW %WECC other 6.7%WECC other 6.7%
16UFLSRG Load Shedding Occurs; Frequency decline was arrested; and, PerformanceThe WECC Plan performed as designed under simulationsLoad Shedding Occurs;Frequency decline was arrested; and,Recovery was observed.
17UFLSRG SW Outage Events Canada and Alberta Initial outage exceeded the 25% resources loss of the UFLS Plan, therefore not a credible island for UFLS – beyond standard requirementsCanada and AlbertaDuring the past 10 years these islands have not formed due to an underfrequency event.
18UFLSRG Review of the last unplanned large loss of generation June 14, 2004
19Disturbance Overview June 14, 2004 at 0741 MST *07/16/96Disturbance OverviewJune 14, 2004 at 0741 MSTWestwing 500 kV / 230 kV and Palo Verde 500 kV subs clearedGeneration Tripped MW’sLoad Interrupted MW’s*
20*07/16/96Event SummaryBird Excrement Caused Fault on Westwing-Liberty 230 kV LineWestwing WW1022 breaker failed to trip (single point of failure – Auxiliary Relay)APS System Operators thought WW 1022 breaker was in the open position during restoration*
22Generation Tripped Palo Verde Units 1, 2 & 3 3796 MW *07/16/96Generation TrippedPalo Verde Units 1, 2 & MWRed Hawk Units 1 & MWDuke Arlington Unit MWOther Units MWTotal MW*
23System Restoration System Frequency recovered within 16 minutes *07/16/96System RestorationSystem Frequency recovered within 16 minutesCOI was over its OTC limit for 13.5 minutesAPS and SRP SOs focused on getting power to Palo Verde*
24UFLSRG Future 2014-15 Islands Simulated E.B.1 & E.B.2 - Planning Coordinators shall participate and identify one or more islands to serve as the basis…UFLSRG has reviewed the past 10 years and configuration of the Western Interconnection
25UFLSRG Proposed Islands to be Simulated 2014-15 WECC North Island South Island
26UFLSRG UFLS Review Group leadership To quote Forrest Gump “ I’m not a smart man”Volunteered for one year in 2008Transferring leadership to Chris Pink