20 MW Wind
Generation
Impact Study
Presented by:
Chadd Jenkins and Trishia Swayne
Agenda
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Utility Background
Study Overview
Data and Assumptions
Analysis Conducted
Impacts and Solutions
Current interconnection status
Tipmont REMC Background Tipmont REMC Background Cont’d •
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Miles of Line Energized: 2,318 Number of Meters: 26,359 Meters per Mile of Line: 10.08 Number of Members: 21,880 Members per Mile of Line: 8.37 Power Supplier: Wabash Valley Power AssociaRon (WVPA) Number of Employees: 67 Tipmont REMC Background Cont’d •  WVPA ̶  All requirements contract  ̶ Partnership with Wind Farm Project  ̶ Point of Common Coupling – DistribuRon Plant ̶  Wind Farm Project – 20 MW Total ̶  (2) 10 MW Projects Study Overview •  20 MW Wind Farm (two 10 MW collector systems) •  Interconnected to 12.47 kV distribuRon •  Two alternaRves invesRgated Study Overview •  AlternaRve 1 Study Overview •  AlternaRve 2 Data and AssumpRons •  Followed IEEE 1547-­‐2008, “IEEE Standard for InterconnecRng Distributed Resources with Electric Power Systems.” •  Peak and minimum load for each substaRon and exisRng feeder •  New overhead construcRon 556 ACSR •  Ten-­‐minute wind speed from Octagon, Indiana •  Wind turbines operated at unity power factor Analysis Conducted Steady State Power Flows Voltage Flicker Risk of Islanding Short Circuit and ProtecRon Impacts and SoluRons •  Steady State –  AlternaRve 1 – conductor loading nearly 100% on both exisRng feeders. Upgrade 336 ACSR to 556 ACSR required. –  AlternaRve 1 and 2 – reverse flow through substaRon regulators. Upgrade controls to cogeneraRon required. –  AlternaRve 1 – high voltage on exisRng feeders. Collector system transformer required to have taps to miRgate. Impacts and SoluRons •  Steady State –  kVAR line losses •  AlternaRve 1 – 6,300 kVAR •  AlternaRve 2 – 10,700 kVAR –  PotenRal TREMC power factor penalRes –  SoluRon is wind turbines to operate off unity to absorb VARs Impacts and SoluRons •  Voltage Flicker –  IEC 61000-­‐4-­‐7 Standard for medium voltage systems •  Pst and Plt calculated •  Evaluates voltage flicker incorporaRng ramping effect of wind or solar •  10-­‐minute actual wind speed measurements used •  Results compared to WindMil study and IEEE 1453 Standard methodology as a base Impacts and SoluRons •  Voltage Flicker Allowable1 AlternaRve 1 AlternaRve 2 County Farm Klondike County Farm Klondike Pst 0.90 0.74 0.72 0.91 0.97 Plt 0.70 0.67 0.65 0.83 0.88 Notes: From IEC 61000-­‐3-­‐7 Table 2 for medium voltage systems Impacts and SoluRons Impacts and SoluRons •  Short Circuit and ProtecRon –  Solidly and effecRvely grounded evaluaRon –  Not solidly grounded with 12.47 kV delta– 0.69kV grounded wye transformers –  Each collector system includes a grounding bank as a soluRon to prevent potenRal overvoltages Impacts and SoluRons •  Short Circuit and ProtecRon –  Fault current contribuRon totals 51,204 amps for full 20 MW site at 690 V, which equates to 1,200 amps LLLG and 1,000 amps LG at 12.47 kV –  Total contribuRon less than 10% of maximum exisRng fault current at each exisRng feeder breaker –  Feeder fuse saving scheme, interrupRng raRngs, pick-­‐ups evaluated –  AlternaRve 1 CF – no protecRve devices between collector system and feeder breaker –  AlternaRve 1 KL – mid stream recloser will be relocated due to project Impacts and SoluRons UnintenRonal islanding The IEEE 1547 Standard states that for an unintenRonal island, the DG shall detect the island and cease to energize the area EPS within two seconds. Limited risk if: • The DR aggregate capacity is less than one-­‐third of the minimum load of the local EPS. • The DR is cerRfied to pass an applicable non-­‐islanding test. disconnect or isolate the DR if power flow from the Area EPS to the Local EPS reverses or falls below a set threshold. • The DR contains other non-­‐islanding means, such as (a) forced frequency or voltage shijing, (b) transfer trip, or (c) governor and excitaRon • The DR installaRon contains reverse or minimum controls that maintain constant power and power flow protecRon, sensed between the Point constant power factor. of DR ConnecRon and the PCC, which will Impacts and SoluRons •  UnintenRonal Islanding –  Analysis determined high risk –  Direct Transfer Trip (DTT) with fiber communicaRng required for both collector systems Impacts and SoluRons Comparison of AlternaRves Alterna(ve 1 – Interconnect to Exis(ng Feeders Alterna(ve 2 – New Direct, Express Feeders There is a reduc,on in the es,mated VAR losses. Increased distances from the substa2on to each collector system leads to higher costs and more VAR losses. The planning-­‐level limits for voltage flicker will be almost fully uRlized with the interconnecRon of each collector system. This Greatly reduces the impact of potenRal voltage flicker on customers served from the substaRon bus on other feeders. does not leave much margin for other industries to come online that could also contribute to voltage flicker. Protec,on scheme must be modified on Klondike 1 Protec2on scheme modified on Klondike feeder 1 for Alterna2ve 1 can be avoided. It will be challenging to upgrade the exisRng overhead on Upgrades to exisRng backbone feeder conductor for County Klondike feeder 1, which is underbuilt on a transmission line. Farm and Klondike, as in AlternaRve 1, can be avoided. Impacts and SoluRons Comparison of AlternaRves Alterna(ve 1 – Interconnect to Exis(ng Feeders Alterna(ve 2 – New Direct, Express Feeders High voltage on the customers near each collector system is expected, but can be mi,gated by each collector system transformer having adjustable taps. Poten,al high voltage for customers served near the interconnec,ons in Alterna,ve 1 can be avoided. EsRmaRng kW losses directly related to the interconnecRon EsRmaRng kW losses directly related to the interconnecRon based on metering to charge to the IC as part of the purchase based on metering to charge to the IC as part of the purchase power agreement will be a less daunRng task than in power agreement will be challenging AlternaRve 1. Exis,ng, available extra feeder bays at each substa,on will remain intact. The spare breaker at County Farm will be u,lized, but replaced with the interconnec,on. The last available bay will be u,lized at Klondike. Current InterconnecRon Status •  Study Complete •  Interconnect Agreement NegoRaRons Stopped QuesRons Trishia Swayne, P.E. Leidos Senior Consultant swaynet@leidos.com 615-­‐431-­‐3227 Chadd Jenkins Tipmont REMC OperaRons and Engineering Manager cjenkins@Rpmont.org (765) 269-­‐4804