Basic study of transient breakdown voltage in solid dielectric cables
A comprehensive review of publications relating to cross linked polyethylene (XLPE) and ethylene propylene rubber (EPR) insulated cables revealed that there is very little known with respect to the life expectancy, the final factory voltage test background and the mechanism of voltage breakdown of these cables. In this study a new methodology was developed which depends on the investigation of breakdown voltages at various voltage transients such as unipolarity pulses and dual-polarity pulses, and ac voltage at power and high frequency. Also, a new approach to statistical testing was developed which allows one to establish a correlation among the breakdown voltages obtained with various voltage transients. Finally, a method for the determination of threshold voltage (true partial discharge inception voltage) regardless of the magnitude of apparent charge was developed. Extensive statistical testing of breakdown voltages was conducted using: impulses with front durations from approximately 1.5 to 1000 ..mu..s and times to half-values from 40 to 3000 ..mu..s; dual-polarity pulses consisting of dc voltage and standard impulse of opposite polarity; combined ac and dc voltages; and ac voltages at power and high frequencies. Based on the results of this testing, a model of breakdown and electrical aging of XLPE and EPR insulated cables was developed as well as life expectancy characteristics for high voltage stress XLPE insulated cables operated in a dry environment at room temperature and at 90/sup 0/C. Life expectancy characteristics for EPR insulated cables are approximated. A test procedure including requirements for full-reel factory voltage withstand and partial discharge testing of finished XLPE and EPR insulated cables is proposed. Cables that pass the proposed tests will exhibit a smaller rate of failure in service than cables tested in accordance with present practices.
- Research Organization:
- Cable Technology Labs., Inc., New Brunswick, NJ (USA)
- DOE Contract Number:
- AC01-78ET29303
- OSTI ID:
- 5278903
- Report Number(s):
- DOE/ET/29303-1; ON: DE82012377
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
EHV & UHV-- (-1989)
200302 -- Power Transmission & Distribution-- DC Systems-- (1989-)
24 POWER TRANSMISSION AND DISTRIBUTION
AC SYSTEMS
AGING
BREAKDOWN
CABLES
CONDUCTOR DEVICES
DATA
DC SYSTEMS
DIELECTRIC MATERIALS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
ENERGY SYSTEMS
EQUIPMENT
ETHYLENE PROPYLENE DIENE POLYMERS
EXPERIMENTAL DATA
FAILURES
HVAC SYSTEMS
HVDC SYSTEMS
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OVERVOLTAGE
PERFORMANCE TESTING
POLYETHYLENES
POLYMERS
POLYOLEFINS
POWER SYSTEMS
TESTING