Kent Bolton & Hari Singh UFLSRG Charter - PowerPoint PPT Presentation

Under-Frequency Load Shedding Review Group Meeting (UFLSRG) October 2, 2019 Kent Bolton & Hari Singh

UFLSRG Charter – Purpose/Responsibilities Purpose: To biennially review the WECC Off- Nominal Frequency Load Shedding Plan (Plan) to help WECC Members meet their compliance obligation to evaluate the Plan’s consistency with NERC Reliability Standard PRC-006. ▪ Conduct biennial simulations of the Plan to assess consistency… report the findings of simulations. ▪ Review the submitted UFLS data for consistency and accuracy of modeling. 2

UFLSRG – History ▪ Created in 2012-13 by JGC to help meet compliance with PRC-006-2 (approved by FERC in 2012) – WECC Variance ▪ WECC UFLS Criterion created as supplement ▪ First UFLS Assessment Report in 2013 ▪ Subsequent Reports in 2015/16 & 2017/18 ▪ 2019/20 Assessment – UFLS simulations will be performed by WECC Staff for first time 3

WECC Island – Imbalance Imbalance = Equivalent Generation Trip MW “Old” (Load – Actual (Target / Actual) Imbalance Generation) / Load 2019 Heavy Summer 2019 Light Spring 23228 / 12850 / 10% ~13% 24187 (10.6%) 13326 (10.5%) 40512 / 22358 / 20% ~23% 41962 (20.8%) 22666 (20.3%) 49153 / 27112 / 25% ~28% 49367 (25.1%) 27613 (25.5%) Actual Generation = Total Generation – Tripped Generation 4

UFLS Design Performance (PRC-006 Attachment 1) Frequency shall remain above/below the Under/Over-frequency Performance Characteristic curve in PRC-006-3 - Attachment 1, either for 60 seconds or until a steady-state condition between 59.3 Hz and 60.7 Hz is reached 5

UFLS Performance Monitored Buses Canada MT/ID/WY WA/OR CO/UT/NV Williston 500 kV Garrison 500 kV Coulee 500 kV Valmy 345 kV Nicola 500 kV Midpoint 500 kV John Day 500 kV Terminal 345 kV Langdon 240 kV Bridger 345 kV Bethel 230 kV Daniels Park 230 kV Kelly Lake 230 kV Wyodak 230 kV Boundary 115 kV Sigurd 230 kV Clover Bar 230 kV Crossover 230 kV Talbot Hill 115 kV Hayden 230 kV Muskeg River 69 kV DRAM 138 kV Port Angeles 69 kV North 115 kV N. California S. California/Mexico S. California/NV AZ/NM Red Mountn 500 kV Vincent 500 kV Moenkopi 500 kV Harry Allen 500 kV Midway 500 kV Imp. Valley 500 kV Rio Puerco 345 kV McCullough 500 kV Gregg 230 kV Sylmar 230 kV Gladstone 230 kV Victorville 500 kV Decatur 230 kV Folsom 230 kV Rosita 230 kV Phoenix 230 kV El Segundo 230 kV Newark 115 kV Mesa Rim 69 kV Alomogordo 115 kV Millers 57.5 kV Rector 66 kV San Onofre 12.47 kV Tucson 47.2 kV 6

10% 2019 LSP Simulation Results 7

10% 2019 LSP Simulation Results 8

25% 2019 LSP Simulation Results 9

25% 2019 LSP Simulation Results 10

10% 2019 HS Simulation Results 11

10% 2019 HS Simulation Results 12

25% 2019 HS Simulation Results 13

25% 2019 HS Simulation Results 14

North & South Islands – Imbalance Generation Trip MW Imbalance = Equivalent (Target / Actual) “Old” (Load – Actual Imbalance Generation) / Load 2019 Heavy Summer North Island South Island 10196 / 11612 / 10% ~13% 12828 (13.5%) 11911 (10.3%) 17760 / 20868 / 20% ~23% 17817 (20.1%) 21150 (20.3%) 21542 / 25497 / 25% ~28% 21615 (25.1%) 25668 (25.2%) Actual Generation = Total Generation – Tripped Generation 15

UFLS Performance Monitored Buses Canada MT/ID/WY WA/OR CO/UT/NV Williston 500 kV Garrison 500 kV Coulee 500 kV Valmy 345 kV Nicola 500 kV Midpoint 500 kV John Day 500 kV Terminal 345 kV Langdon 240 kV Bridger 345 kV Bethel 230 kV Daniels Park 230 kV Kelly Lake 230 kV Wyodak 230 kV Boundary 115 kV Sigurd 230 kV Clover Bar 230 kV Crossover 230 kV Talbot Hill 115 kV Hayden 230 kV Muskeg River 69 kV DRAM 138 kV Port Angeles 69 kV North 115 kV N. California S. California/Mexico S. California/NV AZ/NM Harry Allen 500 kV Red Mountn 500 kV Vincent 500 kV Moenkopi 500 kV McCullough 500 Midway 500 kV Imp. Valley 500 kV Rio Puerco 345 kV kV Gregg 230 kV Sylmar 230 kV Gladstone 230 kV Victorville 500 kV Folsom 230 kV Rosita 230 kV Phoenix 230 kV Decatur 230 kV Newark 115 kV Mesa Rim 69 kV Alomogordo 115 kV El Segundo 230 kV Rector 66 kV San Onofre 12.47 kV Tucson 47.2 kV Millers 57.5 kV 16

North Island - 2019 HS - 10% Imbalance 17

North Island - 2019 HS - 20% Imbalance 18

North Island - 2019 HS - 25% Imbalance 19

South Island - 2019 HS - 10% Imbalance 20

South Island - 2019 HS - 20% Imbalance 21

Next Steps ▪ 2019LSP: Run 10%, 20% and 25% Imbalance Simulations for North & South Islands ▪ All Simulations: Determine V/Hz performance violations using vfmgen model ▪ Sensitivity to DER penetration level • South & North Islands – 2019HS? 2019LSP? Both? • DER level assumption in each control area? • Spread uniformly across All loads in control area? Or only across loads tagged for UFLS? 22

UFLSRG 2018-19 Study Cycle ▪ 2018 June- July: UFLS Data Submission by GO’s and UFLS Entities to WECC ▪ 2018 Aug-Dec: Review/Verify UFLS Data for Consistency and Accuracy; Resolve Issues with entities → Validated UFLS Data in MDF ▪ 2019 Jan-Apr: Build study cases using 2019 Light Spring & 2019 Heavy Summer operating base cases (with updated MDF) ▪ 2019 Apr-Oct June: Perform UFLS Simulations ▪ 2019 Nov July-Oct: Review Results + Draft Report ▪ 2019 Dec Nov: UFLSRG Approval; followed by StS approval (Jan-2020) and RAC+OC approval (Feb-2020) 23

Contact: Hari Singh, Xcel Energy Hari.singh@xcelenergy.com Kent Bolton, WECC kbolton@wecc.org 24