AC-DC ERCOT. Bill Bojorquez Dejan J. Sobajic ERCOT Grid Engineering LLC. June 6, 2005 Les Diablerets, Switzerland

Transcription

1 The 8 th Electric Power Control Centers Workshop June 5-8, 2005, Les Diablerets, Switzerland Panel Session "Monitoring and Control of Large Interconnections under Normal and Emergency Operating Conditions" AC-DC ERCOT Bill Bojorquez Dejan J. Sobajic ERCOT Grid Engineering LLC June 6, 2005 Les Diablerets, Switzerland

2 AC-DC Ties at ERCOT 2

3 Maximum Capacity of AC-DC Ties North DC tie --- ERCOT / SPP (EI) Voltage 345 kv Capacity 220 MW East DC tie --- ERCOT / SPP (EI) Voltage 345 kv Capacity 600 MW Eagle Pass DC tie --- ERCOT / CFE (Mexico) Voltage 138 kv Capacity 36 MW 3

4 Role of AC-DC Ties under normal and emergency operations Normal Operating Conditions There is a 189 MW transfer out of ERCOT for a generator in ERCOT that is owned by entities in the SPP. This transfer is treated as a long term sale in ERCOT reliability analyses. The remainder capacity with SPP is used primarily for commercial transactions. The tie with Mexico was built for reliability purposes Emergency Operating Conditions ERCOT can make use of the DC tie with Mexico for reliability reasons. This tie can provide voltage support and a limited amount of real power (36MW). The ties to EI are not used for voltage support and can only be used for reliability purposes on extreme system emergencies. 4

5 AC-DC Ties: Operations & Market Issues AC-DC Ties Operations AEP (Transmission Owner in ERCOT) operates these ties. The control area operator (ERCOT) has visibility over the status and level of operation but they are operated at the site following set hourly instructions Market Issues Hourly schedules. The 189 MW transfer out of ERCOT for a generator in ERCOT that is owned by entities in the SPP is the only long term obligation. There may be other bilateral agreements, but these are not disclosed to ERCOT. No trading in ancillary services (for load-following, secondary frequency control, spinning reserve) between ERCOT and EI/Mexico ERCOT RC counterparts are SPP (EI) and CFE (Mexico) 5

6 Future Plans Two new back-to-back ties between ERCOT and CFE are planned for Each of them is 150 MW. The first one is a reliability tie in Laredo TX to be built by AEP. The second one is for commercial purposes enabling new trade with Mexico near McAllen TX to be built by Sharyland Utilities. Both will be connected to the 138kV systems. Technologies have not been announced. 6

7 Q&A 7

8 Questions: What is the role of AC/DC links between ERCOT - EI/WI during normal operations? What is the role of AC/DC links between ERCOT - EI/WI during emergency operations? Who controls them? Are special communications needed? How quickly they can be reset if needed? What is the maximum capacity of the links? Are they on hourly/daily schedules? Do they facilitate markets across the interconnection boundaries? i.e. are firm obligations across significant? Are there any bilateral contracts between ERCOT and WI/EI utilities? Is there trading in ancillary services (for load-following, secondary frequency control, spinning reserve) between ERCOT and WI/EI? What EI/WI organization is the counterpart of the ERCOT Reliability Coordinator (on the other side of the links)? 8

9 Appendix: Independent System Operators Key Objectives Enhance interregional reliability through coordinated operations and planning. Facilitate broader competitive markets. Improve flow of information to market participants and the public. 9

10 Appendix: RTO Characteristics & Minimal Functions Characteristics Minimal Functions Independence Scope and Regional Configuration Operational Authority Short Term Reliability Tariff Administration Congestion Management Parallel Path Flow Ancillary Services OASIS and TTC/ATC Market Monitoring Planning and Expansion Interregional Coordination 10

11 Appendix: Existing and Proposed RTOs and ISOs 11

12 NERC Security Coordinators and Interregional Security Network Nodes HQ MARITIMES BPA MAPP OH NYPP NEPOOL MECS PJM PG&E WAPA- Loveland MAIN ECAR AEP APS VP SPP TVA Duke APS Southern Western Interconnection SEC. CTR. ERCOT Interconnection FP&L Eastern Interconnection Security Coordinator Interregional Security Network Node 12

13 NERC Control Areas 13

14 NERC Reliability Coordinators and Independent System Operators 14