High-impedance fault detection using third-harmonic current. Final report
The automatic detection of high-impedance faults on distribution lines is one of the serious problems facing the electric utility industry today. Many utilities depend on phase overcurrent relays and a ground relay to detect downed phase conductors. Overcurrent detection alone is often inadequate because of the high impedance of the ground circuit. A high-impedance fault detector, based on the change of a third-harmonic current, has been developed. Both the phase and amplitude of the third-harmonic current change when a high-impedance fault occurs because of the non-linearity of the earth and arc impedance. The detectors have been successfully field tested on 12-kV distribution circuits and are capable of discriminating between high-impedance faults and other system normal and abnormal events. The performance of the detector has been demonstrated by staged fault tests and ongoing field tests which have accumulated more than 20,000 h of operation at three utilities.
- Research Organization:
- Hughes Aircraft Co., Malibu, CA (USA)
- OSTI ID:
- 5343620
- Report Number(s):
- EPRI-EL-2430; ON: DE82905781
- Country of Publication:
- United States
- Language:
- English
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EHV & UHV-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
AC SYSTEMS
ACCIDENTS
DATA
DESIGN
DETECTION
ELECTRIC GROUNDS
ELECTRICAL FAULTS
ENERGY SYSTEMS
EXPERIMENTAL DATA
INFORMATION
MEASURING INSTRUMENTS
NUMERICAL DATA
OPERATION
PERFORMANCE
POWER DISTRIBUTION
POWER SYSTEMS
POWER TRANSMISSION LINES