EMS LAYOUT BUSA BUSB BUSC Tap BUSD Tap

EMS LAYOUT BUS_A BUS_B BUS_C Tap BUS_D Tap As seen A Obtained load from throwover Diag. 1, from EMS, scheme circuits AB and. Diagram is CD installed have 1 ashows to taptransfer tothe substation layout all of X. It can the ofalso aload substation betoobserved one transformer where thatthe two transformers load if thethrowover other. TR 1 transformer scheme and TR 2 is orare connected implemented. its by supply two open fails. tie breakers. TR 1 TR 2 FDR 1 Legend De-energized Line Transformer Bus FDR 3 Diagram 1: EMS Substation X One-Line FDR 4 Breaker (open) Breaker (closed)

EMS LAYOUT BUS_A BUS_B BUS_C BUS_D Fault In the event of a fault in circuit CD, all the feeders served by TR 2 will be offline. They will remain offline until the tie breakers close to roll the load on transformer TR 1 Feeders 1 and 2 offline FDR 2 TR 2 FDR 1 Legend De-energized Line Transformer Bus FDR 3 Diagram 1: EMS Substation X One-Line FDR 4 Breaker (open) Breaker (closed)

EMS LAYOUT BUS_A BUS_B BUS_C BUS_D Fault By closing the tiebreakers, NOTE: Circuit AB will pickthe up load the offline feeders can be safely load from feeders 1 and 4 in the carried until power eventbyofcircuit a fault. AB in circuit CD. is restored in circuit CD. TR 1 TR 2 FDR 1 Legend De-energized Line Transformer Bus FDR 3 Diagram 1: EMS Substation X One-Line FDR 4 Breaker (open) Breaker (closed)

EMS LAYOUT BUS_A BUS_B BUS_C BUS_D Fault NOTE: Similarly, circuit CD will pick up the load from feeders 2 and 3 in the event of a fault in circuit AB. TR 1 TR 2 FDR 1 Legend De-energized Line Transformer Bus FDR 3 Diagram 1: EMS Substation X One-Line FDR 4 Breaker (open) Breaker (closed)

PSS/E MODEL EMS LAYOUT BUS_A BUS_C BUS_B Tap BUS_D Tap BUS_A Load 1 Branch A 1 TR 1 BUS_B Branch 1 B TR 2 FDR 2 BUS_1 FDR 1 Multi-section line AB BUS_C FDR 3 Load 2 BUS_D FDR 4 Diagram 1: EMS Substation X One-Line Branch C 2 Branch 2 D BUS_2 NOTE: PSSE Similarly, The models tap line tohas the substation to differences substation Xasfrom X by X 2 The A PSSE multi-section model istap adefined few For example, the multi-section line a buses circuit (Bus_1 from ABcircuit isand modeled Bus_2 modeled as )atalayout. the bustaps as (Bus_1) alocation. bus grouping compared several to. CD theispreviously EMS defined For AB hasofbranches A 1 and 1 B. The carrying (Bus_2) substation a carrying load equal is a load referred to the equal sum to to the of the circuit the sum instance, branches ininto PSSE, one long both circuits AB Similarly, multi-section line CDhaving is and ABCD and of losses the CD losses in voltage TR 1 in and TR 2 levels the and (including load the carried in TR 1 several are modeled sub-sections as multi-section or lines. composed of branches C 2 segments. and 2 D. and TR 2 feeders in losses, feeders 2 respectively). and 1 and 3. 4. Multi-section line CD Diagram 2: PSS/E Multi-section lines Legend Load 2 1 = TR 2 TR 1 Losses + FDR 1 FDR 2 ++FDR 3 FDR 4 De-energized Line Bus

EMS LAYOUT BUS_A PSS/E MODEL BUS_C BUS_B BUS_D BUS_A TR 1 Load 1 BUS_B TR 2 FDR 2 BUS_1 FDR 1 BUS_C FDR 3 Load 2 BUS_D FDR 4 Diagram 1: EMS Substation X One-Line BUS_2 NOTE: Recall that circuit AB will pick up the load from feeders 1 and 4 in the event of a fault in circuit CD. Diagram 2: PSS/E Multi-section lines Legend Load Bus_1 Load = TR 1 Losses + FDR 1 + FDR 2 + FDR 3 + FDR 4 De-energized Line Bus

EMS LAYOUT BUS_A PSS/E MODEL BUS_C BUS_B BUS_D BUS_A TR 1 Load 1 BUS_B TR 2 FDR 2 BUS_1 FDR 1 BUS_C FDR 3 Load 2 BUS_D FDR 4 Diagram 1: EMS Substation X One-Line BUS_2 NOTE: Similarly, circuit CD will pick up the load from feeders 2 and 3 in the event of a fault in circuit AB. Diagram 2: PSS/E Multi-section lines Legend Load Bus_2 Load = TR 2 Losses + FDR 1 + FDR 2 + FDR 3 + FDR 4 De-energized Line Bus