A method for preventing misoperation of zero-sequence directional components

Abstract

The invention discloses a zero-sequence direction element maloperation prevention method. The method comprises the following steps that (1) the phase current at a line protection mounting position is acquired; (2) the fault components of the phase current are extracted; (3) whether a maloperation prevention algorithm is started or not is judged according to the starting criteria of the maloperation prevention algorithm, and if yes, the step (4) is executed; (4) the similarity of all phase fault component current waveforms is compared; (5) a perfect circuit is selected according to the similarity comparison result. If the three-phase fault component current waveforms are basically the same, namely the similarity is high, the circuit is judged to be the perfect circuit, and zero-sequence direction elements are locked; if the three-phase fault component current waveforms are large in difference, namely the similarity is low, the circuit is judged to be a fault circuit, and the zero-sequence direction elements are not locked. According to the method, the perfect circuit and the fault circuit can be identified only by circuit single-end currents, the maloperation accidents of the perfect circuit zero-sequence direction elements due to mutual inductance between the circuits are avoided, and the action performance of the zero-sequence direction elements is effectively improved.

Description

【Technical field】 [0001] The invention relates to the field of relay protection for power system transmission lines, in particular to a method for preventing misoperation of zero-sequence directional elements. 【Background technique】 [0002] The application of multi-circuit lines on the same tower is relatively common, especially in Japan and some European countries with developed economy and dense population. In Germany, in order to effectively use the line corridor, the government stipulates that all new lines must be erected more than twice on the same tower. Among its high-voltage and ultra-high-voltage lines, the four circuits in the same tower are conventional lines, with a maximum of six circuits. Due to the shortage of land resources in Japan's Tokyo Electric Power Company, in order to reduce the land use of line corridors, it is possible to use multi-circuit parallel towers. Most of the 110kV and above lines have four circuits on the same tower, and the 500kV line...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a zero-sequence directional element anti-misoperation method to solve the problem of zero-sequence directional protection misoperation of sound lines caused by mutual inductance

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