Phase selection method for ground fault of transmission line based on phase characteristics of sequence voltage difference

Abstract

The invention discloses a power transmission line grounding fault phase selection method based on a sequence voltage difference phase characteristic. According to the method of the invention, phase relationship between a zero-sequence voltage difference and an A-phase negative sequence voltage difference and phase relationship between the zero-sequence voltage difference and an A-phase positive sequence voltage difference are utilized for forming a power transmission line grounding fault phase selection criteria, thereby accurately determining grounding short-circuit fault type of the power transmission line. When a high-resistance grounding short-circuit fault occurs at a weak power supply side on condition that relatively large system operation mode change occurs, the power transmission line grounding fault phase selection method has advantages of realizing high-enough phase selection sensitivity in the whole process of the power transmission line grounding fault, accurately determining a particular grounding fault phase, and supplying accurate and reliable fault phase information for distance protection and accurate action of an autoreclose circuit breaker.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a phase selection method for grounding faults of transmission lines based on sequence voltage difference phase characteristics. Background technique [0002] Phase selection methods for transmission line faults mainly include phase selection of phase current mutation, phase selection of phase voltage mutation and comprehensive phase selection of voltage and current mutation. On the weak power supply side, the phase selection sensitivity of phase current mutation is not high enough; on the strong power supply side, the phase selection sensitivity of phase voltage mutation is insufficient; although the comprehensive phase selection method of voltage and current mutation has relatively high The sensitivity of phase selection is good, but the sensitivity of three-phase short-circuit fault phase selection and high-resistance grounding short-circuit fault...

AI Technical Summary

Problems solved by technology

On the weak power supply side, the phase selection sensitivity of phase current mutation is not high enough; on the strong power supply side, the phase selection sensitivity of phase voltage mutation is insufficient; although the comprehensive phase selection method of voltage and current mutation has relatively high Good phase selection sensitivity, but insufficient sensitivity in phase selection for three-phase short-circuit faults and high-resistance grounding short-circuit faults

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