An adaptive high and low impedance fault detection method

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · IEEE Transactions on Power Delivery (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/61.329514· OSTI ID:6868848

Yu, D C ^[1]; Khan, S H ^[2]

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1. Univ. of Wisconsin, Milwaukee, WI (United States)
2. Puget Sound Power and Light Co., Bellevue, WA (United States)

An integrated high impedance fault (HIF) and low impedance fault (LIF) detection method is proposed in this paper. For a HIF detection, the proposed technique is based on a number of characteristics of the HIF current. These characteristics are: fault current magnitude, magnitude of the 3rd harmonic current, magnitude of the 5th harmonic current, the angle of the third harmonic current, the angle difference between the third harmonics current and the fundamental voltage, negative sequence current of HIF. These characteristics are identified by modeling the distribution feeders in EMTP. Apart from these characteristics, the above ambient (average) negative sequence current is also considered. An adjustable block out region around the average load current is provided. The average load current is calculated at every 18,000 cycles (5 minutes) interval. This adaptive feature will not only make the proposed scheme more sensitive to the low fault current, but it will also prevent the relay from tripping during the normal load current. In this paper, the logic circuit required for implementing the proposed HIF detection methods is also included. With minimal modifications, the logic developed for the HIF detection can be applied for the low impedance fault (LIF) detection. A complete logic circuit which detects both the HIF and LIF is proposed. Using this combined logic, the need of installing separate devices for HIF and LIF detection can be eliminated.

• OSTI ID: 6868848
• Journal Information: IEEE Transactions on Power Delivery (Institute of Electrical and Electronics Engineers); (United States), Journal Name: IEEE Transactions on Power Delivery (Institute of Electrical and Electronics Engineers); (United States) Vol. 9:4; ISSN 0885-8977; ISSN ITPDE5
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
240100* -- Power Systems-- (1990-)
CURRENTS
ELECTRIC CURRENTS
ELECTRIC IMPEDANCE
ELECTRICAL FAULTS
ENERGY SYSTEMS
HARMONICS
IMPEDANCE
OSCILLATIONS
POWER SYSTEMS