Power distribution network outgoing feeder fault route selecting method by S transform amplitude detection

Abstract

The invention relates to a power distribution network outgoing feeder fault route selecting method by S transform amplitude detection, namely, when the power distribution network generates single-phase ground fault, the bus zero sequence voltage before and after the fault can be performed for S transform to find out the moment corresponding to a module maximal value on the S transform highest frequency component position for accurately calibrating the fault moment; the each line zero sequence current before and after the fault moment can be performed for S transform to obtain the S transform complex matrix of each line zero sequence current; the amplitudes of highest frequency component at fault moment in the each line zero sequence current S transform complex matrix can be worked out, andthe amplitude difference can be worked out; the integrative amplitude difference of each line zero sequence current can be worked out; the fault route selecting can be implemented by comparing the size of the integrative amplitude difference. The invention can avoid the route selecting failure caused by CT saturation and phase alternation, the invention implements the route selecting by using high-frequency components, without being influenced by arc-suppression coil compensation degree. The accurate route selecting under different fault conditions comprising small fault angle can be implemented.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a faulty line selection method for distribution network feeder lines using S-transform argument detection. Background technique [0002] Single-phase-to-ground fault line selection in resonant grounding system is a difficult point in distribution network single-phase-to-ground fault line selection. When a single-phase ground fault occurs in the resonant grounding system, the inductance current of the arc suppression coil compensates the capacitive current generated by the fault, so that the fault steady-state current in the fault line is very small, even smaller than the sound line, so the traditional detection based on fault steady-state information The method is not satisfactory for the line selection effect of the resonant grounding system. Using the transient component after the fault to select the fault line has great advantages compared with ...

AI Technical Summary

Problems solved by technology

When a single-phase ground fault occurs in a resonant grounding system, the inductance current of the arc suppressing coil compensates the capacitive current generated by the fault, so that the fault steady-state current in the fault line is very small, even smaller than the sound line, so the traditional detection based on fault steady-state information The method is not satisfactory for the line selection effect of the resonant grounding system

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