Substation voltage upgrading

Technical Report · Wed Apr 01 00:00:00 EST 1992

OSTI ID:5458217

Panek, J; Elahi, H; Lux, A; Imece, A F ^[1]; LaPanse, R A; Stewart, J R ^[2]

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1. General Electric Co., Schenectady, NY (United States). Power Systems Engineering Dept.
2. Public Service Co. of Colorado, Denver, CO (United States)

This report addresses specific issues to support sound yet not unduly conservative uprating practices for substations. The main parts of the report cover the insulation withstand and overvoltage protection aspects, environmental measurements, reliability criteria, and industry experience. First the insulation design concerns are addressed. Substation stress by a backflashover of the line insulation due to lightning in the vicinity of the substation is recognized as a critical stress. A representative part of a 550 kV BIL substation was erected at the EPRI High Voltage Transmission Research Center, where also a special test circuit was assembled to produce a fast front, slow tail (0.2/200 {mu}s) wave. The substation as well as some special configurations were tested for line-to-ground and line-to-line withstand. Computer studies were performed to complement the test results. A number of important conclusions was reached. The most prominent result in that the high frequency oscillations, as caused by reflections within the substation, do not effect the Critical Flashover Voltage (CFO). The present practice, based on the highest peak is therefore very conservative. The slow tail of the wave appears to dictate the CFO. An arrester model for computer studies to represent very fast as well as slow phenomena was derived. It is based on full scale arrester test data, made available in this project. The computer program to calculate arrester model parameters is also a part of the report. The electric environmental measurements are reported for the tested substation at the HVTRC and for the uprated substation of Public Service Company of Colorado, both before and after the uprating. The performance is satisfactory when corona free hardware is used. Insulation design criteria are analyzed based on substation reliability, the system viewpoint and consequences of the failure. Utility experience with uprated substations is reviewed.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); General Electric Co., Schenectady, NY (United States). Power Systems Engineering Dept.; Public Service Co. of Colorado, Denver, CO (United States)
• Sponsoring Organization: EPRI; Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 5458217
• Report Number(s): EPRI-EL-6474-Vol.2
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
POWER SUBSTATIONS
ELECTRICAL INSULATION
AC SYSTEMS
CORONA DISCHARGES
ENVIRONMENTAL IMPACTS
EQUIPMENT PROTECTION DEVICES
FLASHOVER
LIGHTNING
OPTIMIZATION
OVERVOLTAGE
POWER SYSTEMS
SAFETY
STABILIZATION
CURRENTS
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
240201* - Power System Networks
Transmission & Distribution- AC Systems- (1990-)