HVDC wall bushing studies
- General Electric Co., Lenox, MA (USA)
This report describes research conducted to determine the performance of HVDC wall bushings in different wetting conditions. The in-service behavior of these wall bushing on HVDC systems at voltages of {plus minus}450 kV and above is first described to establish the conditions under which flashovers have occurred. Laboratory tests made at the EPRI High Voltage Transmission Research Center confirm that wall bushings may flash over at rated operation voltage under conditions which are intended to be representative of those experienced on operating transmission systems. Methods for improving performance are discussed, and results of tests with several types of mitigation techniques are described. The major emphasis is placed on the application of room temperature vulcanized (RTV) silicone rubber. Clean fog is used to evaluate the characteristics of this material on post insulators. The encouraging performance of the post insulators coated with RTV is the basis for further evaluation on full scale wall bushings tested in nonuniform rain. In addition to tests on RTV coated wall bushings without pre-doposited contamination, attempts at achieving reasonable contamination layers on RV are described. By means of resistance measurements on horizontal insulators, the critical conditions which may lead to flashover on surfaces with different materials and coatings are investigated 15 refs., 39 figs., 11 tabs.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (USA); General Electric Co., Lenox, MA (USA)
- Sponsoring Organization:
- EPRI
- OSTI ID:
- 7080771
- Report Number(s):
- EPRI-EL-6923
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
240202* -- Power System Networks
Transmission & Distribution-- DC Systems-- (1990-)
36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
360603 -- Materials-- Properties
ATMOSPHERIC PRECIPITATIONS
COATINGS
CONTAMINATION
CURRENTS
DC SYSTEMS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATORS
ELECTRICAL PROPERTIES
ENERGY SYSTEMS
EQUIPMENT
FLASHOVER
FUNCTIONS
HVDC SYSTEMS
LEAKAGE CURRENT
MAINTENANCE
MEASURING METHODS
OPERATION
PERFORMANCE
PHYSICAL PROPERTIES
PORCELAIN
POWER SUBSTATIONS
POWER SYSTEMS
POWER TRANSMISSION
PULSES
RAIN
RESPONSE FUNCTIONS
SURFACE PROPERTIES
VARIATIONS