Introduction The need to evaluate the reliability implications of the TEPPC studies was identified as part of 2011 WECC 10-Year Regional Transmission Plan and it has remained strong. As a result and at the request of TEPPC, the Technical Studies Subcommittee (TSS) and its System Review Work Group (SRWG) built the 2022 Light Spring Scenario Base Case 1 as part of its 2012 Base Case Compilation Schedule. This section presents the results of a high-level N-1 contingency analysis performed on the 2022 Light Spring Scenario Base Case. Base Case Modeling and Specification The specification for the 2022 Light Spring Scenario Base Case was taken from the March 31, 2022 2:00 p.m. hour of the 2022 Common Case production cost simulation, an hour in which the Western Interconnection was lightly loaded and had high renewable penetration. The steady-state and dynamic models for the 2022 Light Spring Scenario Base Case were developed in the WECC-approved General Electric (GE) Positive-Sequence Load Flow (PSLF) format and the thermal and voltage analysis module of the GE Energy Steady-State Analysis Tools (SSTools) was utilized to perform a high-level, N-1 contingency analysis on the case. For more detail about steady-state and dynamic models and contingency analysis, please refer to the “Steady-State and Dynamics Models” sub-section of the Tools and Models Report. Steady State Power Flow Analysis The steady-state power flow analysis of the 2022 Light Spring Scenario Base Case involved evaluating: 1) the starting/intact state of the system, as it was built by SRWG; and 2) the resulting state of the system in the event of the loss of any one generator, transformer or transmission line. These states are also typically referred to as N-0 1 Posted among the TSS Base Cases on the WECC website as the “2022 LSP1-SB TEPPC Approved Base Case.” Page 1 of 22 2022 Common Case Reliability Assessment of Light Spring Condition September 19, 2013
Transcript
IntroductionThe need to evaluate the reliability implications of the TEPPC studies was identified as part of 2011 WECC 10-Year Regional Transmission Plan and it has remained strong. As a result and at the request of TEPPC, the Technical Studies Subcommittee (TSS) and its System Review Work Group (SRWG) built the 2022 Light Spring Scenario Base Case1 as part of its 2012 Base Case Compilation Schedule. This section presents the results of a high-level N-1 contingency analysis performed on the 2022 Light Spring Scenario Base Case.
Base Case Modeling and SpecificationThe specification for the 2022 Light Spring Scenario Base Case was taken from the March 31, 2022 2:00 p.m. hour of the 2022 Common Case production cost simulation, an hour in which the Western Interconnection was lightly loaded and had high renewable penetration. The steady-state and dynamic models for the 2022 Light Spring Scenario Base Case were developed in the WECC-approved General Electric (GE) Positive-Sequence Load Flow (PSLF) format and the thermal and voltage analysis module of the GE Energy Steady-State Analysis Tools (SSTools) was utilized to perform a high-level, N-1 contingency analysis on the case. For more detail about steady-state and dynamic models and contingency analysis, please refer to the “Steady-State and Dynamics Models” sub-section of the Tools and Models Report.
Steady State Power Flow AnalysisThe steady-state power flow analysis of the 2022 Light Spring Scenario Base Case involved evaluating: 1) the starting/intact state of the system, as it was built by SRWG; and 2) the resulting state of the system in the event of the loss of any one generator, transformer or transmission line. These states are also typically referred to as N-0 and N-1, respectively, with the “N” meaning any single power system element. This analysis will reference these states as Category A and B events, respectively, which are the official classifications used by WECC and the North American Electric Reliability Corporation (NERC).
Analysis Guidelines and CriteriaDetailed steady-state contingency analyses are regularly conducted at or below the Bulk Electric System (BES) level per NERC Transmission Planning (TPL) standards and as part of area planning activities. Category B contingencies where run for all facilities above 100 kV in the Western Interconnection; however, the scope of the analysis was a high-level reliability assessment of the Western Interconnection, so only issues that appeared on transmission lines, transformers2, and buses above 200 kV were evaluated. In addition, transmission lines and
1 Posted among the TSS Base Cases on the WECC website as the “2022 LSP1-SB TEPPC Approved Base Case.”
2 Transformers were evaluated if either of their buses were above 200 kV.
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2022 Common Case Reliability Assessment of Light Spring Condition
September 19, 2013
transformers with loading above 100 percent of their applicable rating were flagged during the contingency runs; however, only those with loading at or above 110 percent were evaluated as they were likely the most regionally significant. Table 1 and Table 2 summarize the criteria and guidelines against which the 2022 Light Spring Scenario Base Case was evaluated. Southwest Area Transmission (SWAT) suggested voltage ranges as part of the 2011 WECC 10-Year Regional Transmission Plan and their suggestions were retained in this analysis.
Table 1: Criteria for Transmission Line and Transformer Loading
System Event Branch LoadingCategory A Less than 110% of Spring Normal Rating3
Category B Less than 110% of Spring Emergency Rating4
Table 2: Voltage Range Guidelines5 and WECC/NERC Category B Voltage Deviation Criteria6
Nominal Voltage (kV) Operating Limit, kV (Per Unit) Ideal Voltage Range, kV (Per Unit) Category B Voltage Deviation
500 495-551 (0.990-1.102) 525-540 (1.050-1.080) Not to exceed 5% at any bus.
500 (SWAT N-0) 495-545 (0.990-1.090) -- Not to exceed 5% at any bus.
500 (SWAT N-1) 475-545 (0.950-1.090) -- Not to exceed 5% at any bus.
345 327-363 (0.948-1.052) 345-357 (1.000-1.035) Not to exceed 5% at any bus.
345 (SWAT N-0) 342-362 (0.990-1.050) -- Not to exceed 5% at any bus.
287 273-301 (0.951-1.049) 287-293 (1.000-1.021) Not to exceed 5% at any bus.
240 227-253 (0.948-1.052) 240-248 (1.000-1.035) Not to exceed 5% at any bus.
230 218-242 (0.948-1.052) 230-238 (1.000-1.035) Not to exceed 5% at any bus.
230 (SWAT N-0) 228-242 (0.990-1.050) -- Not to exceed 5% at any bus.
220 218-240 (0.991-1.091) 220-235 (1.000-1.068) Not to exceed 5% at any bus.
138 131-145 (0.949-1.051) 138-142 (1.000-1.029) Not to exceed 5% at any bus.
115 110-129 (0.957-1.122) 114-121 (0.991-1.052) Not to exceed 5% at any bus.
Analysis Results - Category AThe 2022 Light Spring Scenario Base Case had no >200 kV branches load at or above 110 percent of their spring normal (Category A) rating; however, it did contain 10 bus voltages which were more than 5 percent different from their scheduled values and outside of the operating limit guidelines specified in Table 2. Table 3 summarizes these buses, their location, and the high-
3 In the WECC-approved GE PSLF model, spring normal and emergency ratings are rating number 7 and 8, respectively.
4 In the WECC-approved GE PSLF model, spring normal and emergency ratings are rating number 7 and 8, respectively.
5 Acceptable voltage ranges are facility-specific and are, therefore, specified by each facility’s owner. The voltage range guidelines are based on the CISO Voltage and VAR Control Procedure No. 3320, feedback from Southwest Area Transmission (SWAT) as part of the 2011 WECC 10-Year Regional Transmission Plan, and expert judgment. The scheduled voltage in the GE PSLF model is also used as a reference - if the voltage is within 5 percent of the scheduled voltage then it is likely an acceptable value.
6 Category B Voltage Deviation taken from the Post Transient Voltage Deviation Standard in WECC System Performance TPL-001-WECC_RBP-2 Regional Business Practice.
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level concerns associated with each. It is important to note that these are strictly concerns based on a high-level screening of the Western Interconnection. As such, they should be used as a starting point for investigations by local planning authorities to improve the review and tuning that goes into the construction of power flow base cases.
Table 3: Notable voltage concerns in the 2022 Light Spring Scenario Base Case prior to any contingency7
Bus NameNominalVoltage
(kV)
Power flowArea Power flow Zone
ObservedVoltage
(kV)
Model'sScheduled
Voltage (kV)DIXIE_345 345 Sierra SPP-TM Load 372.8 345OREANA_345 345 Sierra Zone27 373.5 345
Analysis Results - Category BThe 2022 Light Spring Scenario case was subjected to 16,604 single element contingencies and only 29 (0.17 percent) resulted in unsolved conditions. This analysis focuses only on the results of the 16,575 solved contingency runs because: 1) they represent the gross majority of the run contingencies; and 2) the remaining unsolved runs would require more detailed knowledge of local areas which is beyond the scope of Western Interconnection planning. As stated previously, it is important to note that these are strictly concerns based on a high-level screening of the Western Interconnection and are intended as a proposed starting point for investigations by local planning authorities, who can run these contingencies with the most accurate information and quantify their impact(s).
Bus Voltage ConcernsThere were 13 Category B contingencies which caused multiple voltage concerns in Arizona, southern California, British Columbia, Nevada, New Mexico and Alberta. Table 4 provides a summary of these contingencies and the concerns they raises.
Table 4: Notable Category B Contingencies which caused multiple voltage concerns
Category B Contingency
Concerning ResultsElement Lost8
ElementPower flow
Area
ElementPower flow
Zone
Westwing - Perkins 500-kV Line # 1 AZ WAPA-DSW
Multiple high voltage conditions on 500k-V buses in power flow zones WAPA-DSW and SRP-TSW
RSHASC1 - RSHASC2 500-kV Line # 1
NV ZoneN2
Multiple low voltage conditions on 500-kV, 345-kV, & 230-kV buses in numerous zones of the NEVADA and SIERRA power flow areas
Greenlee - Copper River 345-kV Line # 1
AZ Phelps-DodgeMultiple low voltage conditions on 230-kV & 345-kV buses in the Phelps-Dodge power flow zone in Arizona
San Juan - Ojo 345-kV Line #1 NM ZonePN
Multiple high voltage conditions on 345-kV buses in power flow zones ZoneNO and ZonePN in New Mexico
KMO - KMO SC 287-kV Line # 1 BCH ALCAN
Multiple low voltage conditions on 287-kV buses in the B.C. Hydro and ALCAN power flow zones in the B.C. Hydro
MATLB 240-kV Phase Shifter AB AIES-
Glenwood
Multiple high voltage conditions on 230-kV & 240-kV buses in Alberta's Glenwood and Montana's GTFALLS power flow zones
S. Creek - BCKSP_01 240-kV Line # 18
AB AIES-Fort McMurray
Multiple low voltage conditions on 240-kV buses in Alberta's power flow zones Edmonton/Fort Sask Annex & Fort McMurray
Conklin - BCKSP_01 240-kV Line # 71
BCH ALCAN
Multiple low voltage conditions on 240-kV buses in Alberta's power flow zones Edmonton/Fort Sask Annex & Fort McMurray
Glencany 230kV Phase Shifter AZ WAPA-DSW
Multiple high voltage conditions on 230-kV buses in Arizona's WAPA-DSW power flow zones
8 Some of the names are rather cryptic as a result of how they appear in the power flow model. Local transmission authorities should be consulted to verify the actual real-life names of these facilities.
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NIC 230 - AJX 230P 230-kV Line # 1 BCH BC HYDRO
Multiple low voltage conditions on 230-kV buses in B.C. Hydro power flow area and zones
Frannie - Yellow Tlp 230-kV Line # 1 PACE WY NO EA
Multiple high voltage conditions on 230-kV buses in PacifiCorp East power flow zones
Control - Inyo 115-kV Line # 1 CA_South SCE KRAMER
Multiple low voltage conditions on 230-kV buses in the southern California and Los Angeles Department of Water & Power power flow areas
Blackglade - Shiprock 230-kV Line # 1
WAPA R.M. ZoneR4
Multiple high voltage conditions on 230-kV buses in WAPA R.M. power flow zones
There were 23 Category B contingencies which caused singular voltage concerns in the Northwest, Nevada, Arizona, California, Alberta, British Columbia, Colorado and Montana portions of the Western Interconnection. Figure 1 provides a view of all of the concerning bus voltages resulting from the Category B contingencies, including both the buses associated with multiple concerns per contingencies (listed in Table 4) as well as the singular concerns for added perspective.
Figure 1: Concerning Bus Voltages resulting from Category B Contingencies9
9 Locational data was not available for all of the buses associated with concerning bus voltages.
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Delta Voltage ConcernsThere were 49 Category B contingencies which caused multiple bus voltage deviations in excess of 5 percent of the bus’ pre-contingency (Category A) voltage. Table 5 provides a summary of these contingencies and the concerns they raised.
Table 5: Notable Category B Contingencies which caused multiple voltage deviation concerns
Category B Contingency
Concerning ResultsElement Lost10
ElementPower flowArea
ElementPower flowZone
LANGDON 240-kV Phase Shifter
AB AIES-CalgaryMultiple >5% voltage deviations on 500-kV & 240-kV buses in Alberta's Calgary power flow zone
KMO - KMO SC 287-kV Line # 1
BCH ALCANMultiple >5% voltage deviations on 500-kV & 287-kV buses in British Columbia's B.C. Hydro & ALCAN power flow zones
RSHASC1 - RSHASC2 500-kV Line # 1
NV ZoneN2Multiple >5% voltage deviations on 500-kV, 345-kV, & 230-kV buses in Nevada's ZoneN2 and Sierra's Zone27, TM load, Carlin Trend, & East Tie power flow zones
Garrison - Taft 500-kV Line # 1orGarrison - Taft 500-kV Line # 2
NWUS Western Montana
Multiple >5% voltage deviations on 500-kV buses in Northwest's Western Montana power flow zone
Grassland - Cedar Springs 500-kV Line # 1
NWUSPortland General - BES S/S
Multiple >5% voltage deviations on 500-kV & 230-kV buses in Northwest's Portland power flow zones
AEMNC 500-kV Line # 1
PACE WY SO WEMultiple >5% voltage deviations on 500-kV buses in the Southwest part of Wyoming in PacifiCorp East's power flow area
Clover 500-/345-kV Transformer # 1
PACE UT EA UTMultiple >5% voltage deviations on 500-kV buses in PacifiCorp's Southwest Wyoming, Southwest Utah, & Eastern Utah power flow zones
San Juan - Ojo 345-kV Line #1
NM ZonePNMultiple >5% voltage deviations on 345-kV buses in New Mexico's ZoneNO & ZonePN power flow zones
10 In some cases, multiple contingencies lead to the same concerns. These instances have been aggregated into single rows. In addition, some of the names are rather cryptic as a result of how they appear in the power flow model. Local transmission authorities should be consulted to verify the actual real-life names of these facilities.
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Category B Contingency
Concerning ResultsElement Lost
ElementPower flowArea
ElementPower flowZone
Pinto PS - Four Corners 345-kV Line # 1
PACE UT PINTOMultiple >5% voltage deviations on 345-kV buses in PacifiCorp East's UT Pinto power flow zone
Border Town 345-kV Phase Shifter
Sierra SPP-TM LoadMultiple >5% voltage deviations on 345-kV buses in Sierra's TM Load and #27 power flow zones
Hill Top 345-/230-kV Transformer # 1
Sierra Zone27Multiple >5% voltage deviations on 345-kV buses in Sierra's #27 & TM Load power flow zones
RBFLC - Falcon 345-kV Line # 1
Sierra Zone27 Multiple >5% voltage deviations on 345-kV buses in Sierra's #27 power flow zone
Kit - Kit SC 287-kV line # 1orKit - Kit SC 287-kV line # 2orKit SC87 - KMO SC87 287-kV Line CXorKit SC88 - KMO SC88 287-kV Line CXorKMO87 - KMO SC 287-kV Line # 2orNCT29 - TXW29 500-kV Line # 1orSB1 - SBT 287-kV Line # 1orTXW31 - NCT31 500-kV Line # 1
BCH ALCANMultiple >5% voltage deviations on 287-kV buses in British Columbia's ALCAN & B.C. Hydro power flow zones
9LA57 Tap - BWC01 240-kV Line # 57
AB AIES-Fort McMurray
Multiple >5% voltage deviations on 240-kV buses in Alberta's Fort McMurray, #578, #579, & Edmonton/Fort Sask Annex power flow zones
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Category B Contingency
Concerning ResultsElement Lost
ElementPower flowArea
ElementPower flowZone
Conklin - BCKSP_01 240-kV Line # 71
AB
AIES-Edmonton/Fort Sask Annex
Multiple >5% voltage deviations on 240-kV buses in Alberta's Fort McMurray, Edmonton/Fort Sask Annex, Athabasca/Lac La Biche, & Cold Lake power flow zones
Genesee - Livoc 500-kV Line # 44
ABAIES-Lake Wabamun Generation
Multiple >5% voltage deviations on 240-kV buses in Alberta's Fort McMurray power flow zone
Half - TWR Rd 138-kV Line # 97
ABAIES-Fort Saskatchewan 2000
Multiple >5% voltage deviations on 240-kV buses in Alberta's #579 power flow zone
J Fish - S Creek 240-kV Line # 99
AB
AIES-Edmonton/Fort Sask Annex
Multiple >5% voltage deviations on 240-kV buses in Alberta's Edmonton/Fort Sask Annex power flow zone
Keep Generator # 3
ABAIES-Lake Wabamun Generation
Multiple >5% voltage deviations on 240-kV buses in Alberta's Drayton Valley and Backbone power flow zones
MATLB 240-kV Phase Shifter
AB AIES-Glenwood
Multiple >5% voltage deviations on 240-kV & 230-kV buses in Alberta's Glenwood and Montana's Great Falls power flow zones
Peigan 7 - Sodgl Tap 138-kV Line # 3
AB AIES-Fort MacLeod
Multiple >5% voltage deviations on 240-kV buses in Alberta's Backbone power flow zone
Ruth Lake - Salt Creek 240-kV Line # 23
AB ZONE579Multiple >5% voltage deviations on 240-kV buses in Alberta's Edmonton/Fort Sask Annex & #579 power flow zones
S Creek - BCKSP_01 240-kV Line # 18
AB AIES-Fort McMurray
Multiple >5% voltage deviations on 240-kV buses in Alberta's Edmonton/Fort Sask Annex & Fort McMurry power flow zones
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Category B Contingency
Concerning ResultsElement Lost
ElementPower flowArea
ElementPower flowZone
SEV Generator # 1
BCH BC HYDROMultiple >5% voltage deviations on 240-kV buses in Alberta's Backbone power flow zone
MATLB 240-/230-kV Transformer # 1
AB AIES-Lethbridge
Multiple >5% voltage deviations on 230-kV buses in Montana's Great Falls power flow zone
Copper River - Frisco 230-kV Line # 1
AZ Phelps-DodgeMultiple >5% voltage deviations on 230-kV buses in Arizona's Phelps-Dodge power flow zone
Glencany 230-kV Phase Shifter
AZ WAPA-DSWMultiple >5% voltage deviations on 230-kV buses in Arizona's WAPA-DSW power flow zone
Greenlee - Copper River 345-kV Line # 1
AZ Phelps-DodgeMultiple >5% voltage deviations on 230-kV buses in Arizona's Phelps-Dodge power flow zone
Parker - Gene 230-kV Line # 1
AZ WAPA-DSWMultiple >5% voltage deviations on 230-kV buses in the Municipal Water Department portion of southern California Edison in southern California
NIC - AJX 230-kV Line # 1
BCH BC HYDROMultiple >5% voltage deviations on 230-kV buses in British Columbia's B.C. Hydro power flow zone
Mill Creek 230-kV Phase Shifter
MT BUTTE_MTMultiple >5% voltage deviations on 230-kV buses in Montana's Butte power flow zone
Pillar - Burnham 230-kV Line # 1
NM ZoneWHMultiple >5% voltage deviations on 230-kV buses in New Mexico's ZoneWH power flow zone
Cascade Tap - Sherwood 230-kV Line # 1
NWUSPortland General - BES S/S
Multiple >5% voltage deviations on 230-kV buses in the Portland Area of the Northwest
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Category B Contingency
Concerning ResultsElement Lost
ElementPower flowArea
ElementPower flowZone
Fairmont - Port Ang 230-kV Line # 1orHappy Valley - Port Ang 230-kV Line # 1
NWUSSeattle Area, Olympic Peninsula
Multiple >5% voltage deviations on 230-kV buses in Northwest's Seattle/Olympic Peninsula power flow zones
Lane - Wendson 230-kV Line # 2
NWUS Western Oregon
Multiple >5% voltage deviations on 230-kV buses in the Western Oregon portion of the Northwest
Frannie - Yellow Tlp 230-kV Line # 1
PACE WY NO EAMultiple >5% voltage deviations on 230-kV buses in PacifiCorp East's Central and Northeast Wyoming power flow zones
Grass Creek - Thermo Pl 230-kV Line # 1
PACE WY NO EAMultiple >5% voltage deviations on 230-kV buses in the Northeast part of Wyoming in PacifiCorp East's power flow area
Control - Inyo 115-kV Line # 1
CA_South SCE KRAMERMultiple >5% voltage deviations on 230-kV buses in the southern California and Los Angeles Department of Water & Power power flow areas
Blackglade - Shiprock 230-kV Line # 1
WAPA R.M. ZoneR4Multiple >5% voltage deviations on 230-kV buses in WAPA R.M. power flow zones
Hayden - Foidelck 230-kV Line # 1
WAPA R.M. Zone69Multiple >5% voltage deviations on 230-kV buses in Public Service of Colorado's ZoneRW power flow zone
There were 79 Category B contingencies which caused singular voltage deviations in excess of 5 percent of the bus’ pre-contingency (Category A) voltage. provides a view of all of the concerning voltage deviations resulting from the Category B contingencies, including both the buses associated with multiple concerns per contingencies (listed in Table 5) as well as the singular concerns for added perspective.
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Figure 2: Concerning Bus Voltage Deviations resulting from Category B Contingencies11
Branch Loading ConcernsThere were eight branches (three transmission lines and five transformers) loaded at more than 110 percent of their Spring Emergency (Category B) rating as a result of 11 Category B contingencies. Table 6 provides a summary of these branches and the contingencies which caused their high loading.
11 Locational data was not available for all of the buses associated with concerning bus voltage deviations.
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Table 6: Branches loaded 110% or higher due to Category B contingencies
Monitored Branch with Concerning Loading Category B Contingency
Branch Name
Spr.Cat ARating(MVA)
Spr.Cat BRatin
g(MVA)
Cat ALoading
(%)
Cat BLoading
(%)
Power flowArea
Power flowZone Element Lost Power flow
AreaPower flow
Zone
DR E Tap - Dalreed 230-kV Line # 1 348 348 95.9 158.9 NWUS PAC:DALR Santiam - Tmbl Creek 230-kVLine # 1 NWUS Western Oregon
DR W Tap - Dalreed 23-0kV Line # 1 401 401 84.3 139.1 NWUS PAC:DALR Santiam - Tmbl Creek 230-kV
Wolcott - Foidelck 230-kV Line # 1 180 180 88.7 111.7 PS CO ZoneRW Gorepass - Hayden 230-kVLine # 1 PS CO ZoneRW
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Conclusions and Recommendations
Category A: Need for greater collaboration and improved base case reviewThe bus voltage issues identified in the 2022 Light Spring Scenario case can likely be eliminated with further tuning the power flow case, such as reviewing the scheduled voltages on these buses and making sure that they accurately reflect their real-life voltage set points. These concerns should have been identified and fixed during the construction and review of the base case; however, they are minimal considering the amount of data contained in the power flow.
The effort to construct the base case from specifications taken from a PCM was major cross-functional effort between regional planning engineers and resource planners across the Western Interconnection. As a result, improving current power flow model review processes and increasing collaboration between local planning authorities would likely reduce the prevalence of these issues.
Category B: Voltage concerns are most likely due to the large renewable resource injection across the Western InterconnectionThe regional bus voltage concerns resulting from the Category B contingencies were largely in Alberta, southern Nevada, central California, Arizona and New Mexico. The regional bus voltage deviation concerns were located in similar portions of the Western Interconnection, as well as in Wyoming, Oregon, and the west cost of British Columbia.
The bus voltage concerns are expected because most of these areas are the primary locations for future renewable resources. The 2022 Light Spring Scenario Base Case was built from an RPS-compliance PCM which contained many renewable resource projects that were only in the planning stages, most of which did not have definite capabilities, site configurations, or locations. As a result, modeling the PCM’s planned resources involved making general assumptions with regard to their configuration, capability and point of interconnection. In addition, the main effort was in constructing the case rather than running sensitivities to identify appropriate reinforcements necessary to adequately integrate these resources into the power system.
Branch loading are most likely due to discrepancies in facility ratings or incomplete switching information due to the loss of certain elements.The branch loading concerns occurred in the Northwest, Sierra, Arizona and Public Service of Colorado power flow areas. Many of the branches with concerning flows have the same rating for Spring Normal and Emergency. A facility’s emergency/temporary rating is typically more than its normal/continuous, so many of these concerns would likely be resolved after reviewing the facilities’ ratings. In addition, this analysis did not account for any local automated switching in response to the loss of certain facilities, so these actions may also alleviate these concerns.
Recommended starting point for local planning authorities’ investigationsTable 7 shows the 62 contingencies run during this analysis which resulted in regionally significant concerns regarding bus voltage values, bus voltage deviations and branch loading.
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2022 PC1 Common Case
Local planning authorities should verify that these or more updated/accurate versions of these contingencies are run during their regular planning activities.
Table 7: Category B Contingencies which resulted in Regional Concerns
ElementPower flowArea
Element Lost
AB
9LA57 Tap - BWC01 240-kV Line # 57Conklin - BCKSP_01 240-kV Line # 71Genesee - Livoc 500-kV Line # 44Half - TWR Rd 138-kV Line # 97J Fish - S Creek 240-kV Line # 99Keep Generator # 3LANGDON 240-kV Phase ShifterMATLB 240-/230-kV Transformer # 1MATLB 240-kV Phase ShifterPeigan 7 - Sodgl Tap 138-kV Line # 3Ruth Lake - Salt Creek 240-kV Line # 23S Creek - BCKSP_01 240-kV Line # 18S. Creek - BCKSP_01 240-kV Line # 18
AZ
Copper River - Frisco 230-kV Line # 1Four Corners - Moenkopi 500-kV Line # 1Four Corners 500-/345-kV Transformer # 1Glencany 230-kV Phase ShifterGlencany 345-/230-kV Transformer # 1Glencany 345-/230-kV Transformer # 2Greenlee - Copper River 345-kV Line # 1Parker - Gene 230-kV Line # 1Westwing - Perkins 500-kV Line # 1
BCH
Conklin - BCKSP_01 240-kV Line # 71Kit - Kit SC 287-kV line # 1Kit - Kit SC 287-kV line # 2Kit SC87 - KMO SC87 287-kV Line CXKit SC88 - KMO SC88 287-kV Line CXKMO - KMO SC 287-kV Line # 1KMO87 - KMO SC 287-kV Line # 2NCT29 - TXW29 500-kV Line # 1NIC - AJX 230-kV Line # 1
BCH
NIC 230 - AJX 230P 230-kV Line # 1SB1 - SBT 28-7kV Line # 1SEV Generator # 1TXW31 - NCT31 500-kV Line # 1
MT Mill Creek 230-kV Phase Shifter
Page 14 of 15
2022 PC1 Common Case
ElementPower flowArea
Element Lost
NV RSHASC1 - RSHASC2 500-kV Line # 1
NMPillar - Burnham 230-kV Line # 1San Juan - Ojo 345-kV Line #1
NWUS
Cascade Tap - Sherwood 230-kV Line # 1Fairmont - Port Ang 230-kV Line # 1Garrison - Taft 500-kV Line # 1Garrison - Taft 500-kV Line # 2Grassland - Cedar Springs 500-kV Line # 1Happy Valley - Port Ang 230-kV Line # 1Lane - Wendson 230-kV Line # 2Santiam - Tmbl Creek 230-kV Line # 1
PACE
AEMNC 500-kV Line # 1Clover 500-/345-kV Transformer # 1Frannie - Yellow Tlp 230-kV Line # 1Grass Creek - Thermo Pl 230-kV Line # 1Pinto PS - Four Corners 345-kV Line # 1
PS CO Gorepass - Hayden 230-kV Line # 1
Sierra
Border Town 345-kV Phase ShifterHill Top 345-/230-kV Transformer # 1RBFLC - Falcon 345-kV Line # 1Valmy - Falcon 345-kV Line # 1
CA_South Control - Inyo 115-kV Line # 1
WAPA R.M.
Blackglade - Shiprock 230-kV Line # 1Craig - Meeker 345-kV Line # 1Hayden - Foidelck 230-kV Line # 1Weld PS - Weld LM 115-kV Line # 1
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