Distribution network fault line selection method based on zero sequence current variable quantity waveform correlation coefficient matrix

Abstract

The invention discloses a distribution network fault line selection method based on a zero sequence current variable quantity waveform correlation coefficient matrix. According to the distribution network fault line selection method disclosed by the invention, a row off-diagonal element of each feeder zero sequence current variable quantity waveform correlation coefficient matrix and feeders in minimum corresponding before and after switching of a parallel resistance are utilized to carry out line selection for a fault line principle; and zero sequence voltage of a distribution network bus is larger than 15% phase voltage, the parallel resistance is switched by keeping arc suppression coil parameters invariable, a zero sequence current sampling value of each feeder flowing before and after switching of the parallel resistance is measured, the zero sequence current variable quantity waveform correlation coefficient matrix is further calculated, and the row off-diagonal element of each feeder zero sequence current variable quantity waveform correlation coefficient matrix and the feeders in minimum corresponding are selected as fault lines. With the adoption of the method, a line selection result is not influenced by factors such as transition resistance, line parameters, line length, distribution network running mode and fault position, the line selection principle is simple, and the line selection result is high in reliability and strong in practicability.

Description

technical field [0001] The invention relates to the technical field of power system distribution network fault line selection, in particular to a distribution network fault line selection method based on zero-sequence current variation waveform correlation coefficient matrix. Background technique [0002] After a single-phase fault occurs on the distribution network feeder whose neutral point is grounded through the arc-suppression coil, the inductive current provided by the arc-suppression coil compensates the capacitive current at the ground point of the fault line. The zero-sequence current is still small, so that the distribution network fault line selection method based on the zero-sequence current method (such as "New Criteria for Small Current Grounding Line Selection Based on Zero-Sequence Current Transient Maximum Value" published by Zhang Fan, Pan Zhencun, and Zhang Huifen) ) The line selection results are not reliable enough. Due to the compensation effect of the...

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Problems solved by technology

However, the fault signal in the small current grounding system is very weak, and the fault wave head of the fault waveform is difficult to identify, which makes it difficult for the online application of the traveling wave method

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