Transmission Reliability. BCUC Workshop 15 January 2004

Transcription

1 Transmission Reliability BCUC Workshop 15 January 2004

2 Overview British Columbia Transmission Corporation (BCTC) is responsible for planning, operating and managing BC Hydro s transmission system pursuant to the Transmission Corporation Act. BCTC scope of responsibilities includes all components from the generator step-up transformer to the substation fence, including control and telecommunications systems. Transmission Reliability BCUC Workshop 15 January 2004 Page 2

3 Overview (cont d) A key element of BCTC s responsibility is to ensure reliability and security of the bulk transmission network and reliability at delivery points serving distribution systems and direct-connected transmission voltage customers. The Revenue Requirement Filing identifies system reliability as one of BCTC s key cost drivers. Transmission Reliability BCUC Workshop 15 January 2004 Page 3

4 Overview (cont d) BCTC is operating, maintaining and expanding a transmission system that is aging and subject to increasing use due to load growth and trade volume. The majority of transmission assets were installed between the 1940 s and 1980 s and are nearing end-of-life. Vegetation management is more extensive because trees on transmission corridors have matured. Given the economic costs of system failure, maintenance and investment programs have been adjusted to reflect the current state of the system. Transmission Reliability BCUC Workshop 15 January 2004 Page 4

5 Considerations Reliability Standards The transmission system is planned and operated in accordance with reliability criteria and standards established by the Western Electricity Coordinating Council (WECC) and the North American Electric Reliability Council (NERC). These standards ensure high reliability and safe operation of the bulk system, while limiting the impact of disturbances in one utility on adjacent utilities. Transmission Reliability BCUC Workshop 15 January 2004 Page 5

6 Compliance Programs In 1999, with BCUC approval, BC Hydro adopted WECC s voluntary Reliability Management System, the only such program in place among North American reliability councils. The program involves monitoring, reporting and sanctions for non-compliance. BC Hydro performance under this program has been very positive. Transmission Reliability BCUC Workshop 15 January 2004 Page 6

7 BCTC Standards Maintenance Standards All maintenance work is completed to standard, in a timely manner, cost effectively, safely and in an environmentally sensitive manner. Maintenance Standards are reviewed and updated regularly enabling continuous improvement of the maintenance process. Design Standards The transmission system is designed to withstand individual component failures as well as system impacts from other utilities, fluctuations in load, voltage and interutility transfers. This is accomplished through engineering studies and application of rigorous design standards. Transmission Reliability BCUC Workshop 15 January 2004 Page 7

8 Operational Issues Recognizing the critical role of system operators, BCTC invests in training facilities and programs. All system operators and supervisors have achieved WECC and NERC certification. System operators utilize advanced analytical tools to maximize grid utilization while maintaining reliability. Bulk system performance has been excellent during extreme conditions, most recently in 1996 when major disturbances occurred in the Western interconnection. Transmission Reliability BCUC Workshop 15 January 2004 Page 8

9 Delivery Point Reliability In addition to bulk system reliability, the transmission system is planned, operated and maintained to meet customer service expectations and to avoid the economic consequences of delivery point outages (also known as source outages). Transmission Reliability BCUC Workshop 15 January 2004 Page 9

10 Transmission Reliability Measurements ASAI Average Service Availability Index - % of time service is available. CAIDI Customer Average Interruption Duration Index - total customer hours of interruption per total customer interruption. SAIDI System Average Interruption Duration Index - total customer hours of interruption per total customer served. SAIFI System Average Interruption Frequency Index - frequency of interruptions per delivery point. SARI System Average Restoration Index Per Delivery Point - average time to restore service. Transmission Reliability BCUC Workshop 15 January 2004 Page 10

11 Delivery Point Reliability (cont'd) The contribution of transmission delivery point outages to total customer hours lost: Distribution 85% Transmission 57% 15% Substation 39% Source Other 4% Transmission Reliability BCUC Workshop 15 January 2004 Page 11

12 Breakdown of 2002/03 Substation Source Outages by Cause Animal 37.8% Equipment Failure 10% Human Element 3.0% MVA 2.8% Planned Outages 0.2% Unknown 9.8% Other 6.5% Birds 23.5% Adverse Weather 6.5% Transmission Reliability BCUC Workshop 15 January 2004 Page 12

13 Breakdown of 2002/03 Transmission Outages by Cause Trees 34.2% MVA 10.2% Lightning 0.8% Equipment Failure 5.0% Adverse Weather 25.6% Planned Outages 7.2% Flood, Mud/ Snow Slide 8.4% Pole Top Fire 5.6% Other 3.1% Transmission Reliability BCUC Workshop 15 January 2004 Page 13

14 Benchmarking Canadian and international benchmarks are used to evaluate performance and practices, and to identify areas for improvement. PA Consulting Benchmark Results, 2002/03 Survey 2002 Performance All Participants BCH Transmission Mean 1 st Quartile Value Quartile Cost Measures Transmission Expenditures per struct-mile ($US) 28,437 12,557 11,915 1 st T&D Substation Expenditures ($US / MVA) 2,347 1,372 1,350 1 st Reliability Measures Transmission Line Sustained Forced Outage Events nd per 100 circuit miles Transmission Line Momentary Forced Outages per st 100 circuit miles T&D Substation Contribution to SAIDI (Minutes) rd Transmission Reliability BCUC Workshop 15 January 2004 Page 14

15 Canadian Electricity Association 3.50 SAIDI- Total Interruption Duration That a Delivery Point Experiences Per Year SAiDI Total Duration Forecast value predicted from 5- year historical data BCH-BES SAIDI CEA-BES SAIDI Y ear Transmission Reliability BCUC Workshop 15 January 2004 Page 15

16 Benchmarking Analysis Geography, terrain and weather contribute to second quartile performance for transmission sustained forced outages. Technology applications and improved asset management strategies are being pursued to improve this performance. Substation contributions to customer reliability are in third quartile. Major contributors include radial feeds in remote areas, aging infrastructure and animal-related outages. Strategies are being pursued to reduce animal outages, improve equipment health, and reduce personnel errors. Transmission Reliability BCUC Workshop 15 January 2004 Page 16

17 Implications for Asset Management Programs Aging equipment and encroaching vegetation are raising reliability concerns. This is driving BCTC s revenue requirement for increased maintenance OMA and increased sustaining capital expenditures in the test periods and beyond. This perspective is supported by the benchmarking results which reflect a relatively low-cost asset management program in the past, but emerging reliability concerns. The revenue requirement filed reflects only the cost of dealing with the issues known to us at this point. A full audit of the system inventory has begun to determine the state of the system accurately. The result will be reflected in future applications. Transmission Reliability BCUC Workshop 15 January 2004 Page 17

18 Expenditure Summary Expenditures required to address transmission reliability issues are reflected in the following OMA and Capital Plan summaries: Operating, Maintenance and Administration Costs* F2004 (in millions of dollars) F2003 Actual Forecast F2005 Plan F2006 Plan Transmission System Operation Asset Management and Maintenance General and Administration BC Hydro Rights Management, Properties, and Asset Retirement Obligation Total Deduct: Cost Recoveries (6.4) (6.5) (5.1) Total per Financial Statements * F2003 costs are not available in the same categories as subsequent years due to accounting and restructuring changes that occurred post F2003. Transmission Reliability BCUC Workshop 15 January 2004 Page 18

19 Expenditure Summary (cont'd) Transmission Capital Plan F F2006 $ Millions F04 F05 F06 Sustaining BCHydro Transmission BCTC Total Sustaining Capital Growth BCHydro Transmission BCTC Total Growth Capital Total Capital Expenditures Transmission Reliability BCUC Workshop 15 January 2004 Page 19