Phase Selection Method for Line Grounding Fault Using Sequence Current Phase Characteristics

Abstract

The invention discloses a line grounding fault phase selection method by means of a sequence current phase characteristic. According to the method of the invention, a zero-sequence current, an A-phase negative-sequence current and an A-phase positive-sequence current jump value are firstly measured. Then phase relationship between a zero-sequence current and an A-phase negative-sequence current and phase relationship between the zero-sequence current and the A-phase positive-sequence current jump value are utilized for forming a 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 relatively large change of a weak power side and system operation mode occurs, the method of the invention has advantages of realizing high-enough phase selection sensitivity, 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 method for realizing line grounding fault phase selection by utilizing sequence current 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 is insufficien...

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

Images