Revised Generation Interconnection Impact Study Report. For. Queue Position 31 ( Interconnection Customer )

Transcription

1 Revised Generation Interconnection Impact Study Report For Queue Position 31 ( Interconnection Customer ) September 22,

2 Generation Interconnection System Impact Study Report I. Revision of Original Impact Study This Impact Study is revised from its original version dated July 28, 2004 due to a need to revise the interconnection point with PacifiCorp s system. II. Project Description Interconnection Customer plans to interconnect a new wind farm that borders highway 74 and is located in Morrow and Gilliam County, Oregon, in the vicinity of Township 2 N, Range 23 E. The expected commercial operation date is May 1, The proposed point of interconnection is at the 34.5 kv voltage of PacifiCorp s existing Dalreed Substation. The Substation consists of three 230/115 kv transformers with a combined capacity of 70 MVA. The summer load on the Station is about 35 MVA, the winter load is 10 MVA. BPA s 230 kv Santiam McNary line connects to the Substation. The wind farm will use two step-up transformers, each with three wind turbine-generator feeders. The study assumes that General Electric 1.5 MW wind turbines would be used. Interconnection Customer plans to install 48 GE wind turbines with a peak output capability of 72 MW. Interconnection Customer s interconnection request is for 85 MW. However, transformer capacity upgrades at Dalreed will be required should the wind farm capacity be greater than 72 MW. III. Study Objective The objective of the Generation Interconnection System Impact Study Report is to provide a high level definition of system modifications and additions required for generation interconnection. Design detail, schedule and costs will be dealt with next, in the Facilities Study. The scope of the modifications for this Interconnection Impact Study does not include modifications required to deliver power beyond the point of interconnection. Such modifications are considered in a Transmission Service Impact Study. The Generation Interconnection Impact Study is required by PacifiCorp s FERC Tariff, 5 th Revised Volume No 11. ] IV. Study Results A. Modifications and Additions to Facilities at PacifiCorp Interconnection Location The following one line diagram shows the substation equipment that will be needed for connecting your generation facility to Dalreed Substation. 2

3 Santiam 230kV McNary DALREED SUB Simtag Feeder #2 Boeing Feeder #1 10 Miles INTERCONNECTION CUSTOMER S SUB 34.5kV COLLECTOR #1 COLLECTOR #2 The clouded area on the one line diagram shows the new equipment at Dalreed Substation. A 34.5kV breaker and a half bus arrangement would be installed at Dalreed Substation to accommodate the two new 34.5kV lines from Interconnection Customer s substation and to make it possible to operate Dalreed Substation in the configuration that will be needed to handle the additional power flow. Dalreed Substation currently has three kV transformers but the three transformers are not operated in parallel. To accommodate the power from the wind farm the three transformers will need to operate in parallel. A change in the 34.5kV bus arrangement will be needed for this change in operation. Seven additional 34.5kV breakers will be needed. Two of these breakers are replacing existing breakers that do not have the current interrupting capability to handle the 3

4 increase in fault duty. Additional property may need to be acquired to accommodate the additional bus work and structures. The control house will need to be added on to, to accommodate the additional protection and control equipment. Pilot line protective relays will be installed on both ends of the two 34.5kV lines between Dalreed Substation and Interconnection Customer s Substation. These relay systems will detect line faults and trigger the isolation of the faulted line. To provide the communication needed for the transmission lines protection a fiber optic cable should be installed on at least one of the new transmission lines. A line protection package will be installed at Dalreed Sub to detect faults on the 230kV lines. This line protection package will be connected to current transformers on the 230kV side of the power transformers and a new set of 230kV potential transformers. If there is a fault on the 230kV lines these relays will trip the breakers at Dalreed Sub on the 34.5kV lines to Interconnection Customer s Substation. This will disconnect Interconnection Customer s generator infeed to the 230kV line fault and permit the restoration of the 230kV system for a nonpermanent line faults condition. This line protection package will communicate to the line relays on the other two terminals of the line through the microwave system. The 230kV neutral bushings of the kV transformers are currently not grounded. To facilitate the detection of ground faults on the 230kV line by the new line relay package it will be beneficial to ground those neutral bushings. Besides the protective relaying for the line protection under/over voltage and under/over frequency relaying at the wind farm, noted in PacifiCorp s Interconnection and Operating Requirements, will also be needed. A new RTU will be needed at Dalreed Substation. This RTU can be of a distributed design to bring back the status and analog data needed from Interconnection Customer s Substation to PacifiCorp Control Center, as well as provide control, indication and analog signals for Dalreed Substation. The following data will be needed from Interconnection Customer s Substation: Status of the position of all 34.5kV breakers, including wind turbine feeder breakers and supplemental shunt capacitor breakers. MW and MVar flow on each of the 34.5kV wind turbine feeder breakers Total MVar flow on the supplemental shunt capacitor banks. 34.5V voltage at Interconnection Customer s Substation Wind velocity at the wind farm MWh pulse accumulators for energy flow through each of the 34.5kV breakers 4

5 Telemetering equipment will be installed at Interconnection Customer s Substation to communicate to PacifiCorp s EMS the level of power being produced by the wind farm. For the SCADA and telemetering a communication path will be needed between Interconnection Customer s facility and PacifiCorp s Portland Control Center. B. Other Modifications to Existing Facilities 1. Short Circuit Analysis A fault analysis was performed using the computer software Aspen GE 1.5 MW wind turbines connected through the 34.5kV collector system was added to the latest Aspen One-liner Base Case. The 34.5kV collector system was modeled using the information supplied by the developer. Classical faults were simulated at several key locations. These faults were simulated to determine if the existing breakers had sufficient interrupting capacity. The following table lists the in fault duty on buses in the vicinity of the new generation facility. Interconnection Customer Generation Addition Substation Bus 3 phase fault Single line to ground fault Dalreed 230kV 5181 A 4056 A Dalreed 34.5kV 9214 A A Santiam 230kV A A The study showed that two out of the four 34.5kV circuit breakers at Dalreed Sub will need to be replaced due to increased fault duty caused by the addition of the generation facility. 2. Protection & Controls 5

6 The protective relay system s at BPA s McNary Sub on the line to Dalreed and at BPA s Santiam Sub on the line to Dalreed will need to be modified. 3. Communications V. Potential Third Parties Impacted Bonneville Power Administration A new GE ES D20 RTU will be installed at Dalreed Sub, configured to accept a distributed input. The distributed portion of the RTU will be installed at Interconnection Customer s sub. The distributed RTU will communicate directly with the D20 master over dedicated fiber between the Interconnection Customer substation and Dalreed Sub. Two telemetry transmitters and a shelf will be installed at the Interconnection Customer sub to send tones for MW and MVar quantities back to PCC and Keys Road. For meter and relay dial-up, as well as voice communication, a Line Sharing Switch will be installed at the Interconnection Customer Sub. Circuits required to access these systems, as well as any additional requests from Interconnection Customer, will be brought into the Interconnection Customer Sub through a channel bank installed at the substation. T1 fiber modems will be installed to communicate over the fiber between the Interconnection Customer Sub and Dalreed Sub. The six-channel analog microwave currently connecting Dalreed Sub to PacifiCorp s communication system will be replaced with a DS3 digital Harris Constellation radio link to Roosevelt comm site. An Integrated Access Device will be installed at Dalreed Sub and Roosevelt comm site to channelize circuits from Interconnection Customer and Dalreed to PCC, Yakima, and Kennewick comm site. Protective Relaying circuits for BPA McNary and BPA Santiam will be channelized to Kennewick comm site and handed to BPA. At PCC, the EMS database will be modified to add the Dalreed/Interconnection Customer points. Telemetry Receivers will be installed to input MW and MVar values into EMS. At Keys Road, telemetry receivers will be installed to input MW and MVar vaules into EMS. Any new voice circuits will be channelized into the Keys Rd PBX. 6

7 VI. VII. Possible Additional Studies Required During Facilities Study Phase None anticipated Exclusions/Disclaimers The impacts and modifications discussed in this report are those required to interconnect the generating facilities to PacifiCorp s transmission system. They are not sufficient to deliver power beyond the point of interconnection. As soon as PacifiCorp receives a request for transmission service from the Interconnection Customer, or its agent, and/or has been notified that it is an affected system for a transmission service request received by another utility, PacifiCorp will conduct a transmission service impact study to determine if additional modifications are required to deliver power beyond the point of interconnection. The study will include power flow and transient stability analyses. The stability analysis will require that the Interconnection Customer provide a model of the wind turbines it intends to use, in a format compatible with PacifiCorp s PTI software. VIII. Conclusions and Recommendations 1. Reconfigure PacifiCorp s 34.5 kv Dalreed Substation yard to accommodate the paralleling of the Substation s three existing 230/34.5 kv transformers, two new 34.5 kv interconnecting lines from Interconnection Customer s Substation and service to three other locations. Five new 34.5 kv breakers and corresponding switches are required. The existing control house will need to be expanded to accommodate the the additional protection and control equipment. Additional property may need to be acquired to accommodate the expansion. 2. Both of the ten mile interconnecting 34.5 kv lines will be protected with pilot line protective relays. Fiber optic cable will be installed on the new transmission line to allow for protection system communication. To facilitate the detection of ground faults on the 230 kv system, by the new relay package, it will be beneficial to ground the neutral bushings on the 230/34.5 kv transformers. 3. Two existing 34.5 kv breakers at Dalreed must be replaced due to increased fault duty caused by the addition of the generation facility. 4. Interconnection Customer must install voltage and frequency protection that will delay tripping wind turbines feeder breakers until frequency or voltage swings outside WECC prescribed limits and time delays. 5. The protective relay systems at BPA s McNary and Santiam substations will need to be modified. 6. A new RTU will be installed at Dalreed Substation. This RTU should use a distributed design to bring back status and analog data from the wind farm, including: status of all 34.5 kv breakers, including wind turbine feeder breakers and 7

8 supplemental shunt capacitor breakers; MW and MVar flow on each of the 34.5kV wind turbine feeder breakers; total MVar flow on the supplemental shunt capacitor banks; 34.5V voltage at Interconnection Customer s Substation; Wind velocity at the wind farm; and MWh pulse accumulators for energy flow through each of the 34.5kV breakers. 7. Analog microwave equipment connecting Dalreed to PacifiCorp s communication system will be replaced by digital microwave equipment. Communication equipment will also be installed at Roosevelt Comm Site, PCC, Yakima, Kennewick Comm Site and Keys Road. 8. Protective relaying circuits for BPA McNary and BPA Santiam will be channelized to the Kennewick Comm Site. 8