Realizing Phase Selection Method for Line Grounding Fault Using Current Phase Characteristics of Fault Point

Abstract

The invention discloses a line grounding fault phase selection method realized by means of fault point current phase characteristic. According to the method of the invention, phase relationship between a fault point zero-sequence current and a fault point A-phase negative-sequence current and phase relationship between the fault point zero-sequence current and a fault point A-phase positive-sequence current are sued for forming a power transmission line grounding fault phase selection criteria, thereby accurately determining the type of a power transmission line grounding shortcircuit fault. When high-resistance grounding shortcircuit fault of a power transmission line occurs on condition that a relatively large change of a weak power supply side and system operation mode occurs, the method of the invention has advantages of realizing a high-enough phase selection sensitivity in whole fault 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 correct 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 method for realizing line grounding fault phase selection by utilizing the current phase characteristics of fault points. 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 is ...

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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