Small current line selection method utilizing wavelet analysis

Abstract

The invention discloses a small current line selection method using wavelet analysis. Wavelet transform and modulus maximum representation thereof can accurately score fault characteristics of transient traveling waves; the method has a step of extracting grounded traveling wave information to form effective grounding line selection criterion; initial transient traveling waves of a fault line anda sound line have obvious characteristic difference. Therefore, the modulus maximum value of wavelet transform is used for representing the amplitude and polarity characteristics of the initial traveling wave on each line; according to the method, the fault line selection criterion can be formed according to the amplitude and polarity difference of the modulus maxima of the initial traveling wavesof all the lines, and line selection is accurate and high in speed according to the amplitude and polarity difference of the modulus maxima of the initial traveling waves of all the lines by means ofthe wavelet analysis small current line selection method.

Description

technical field [0001] The invention relates to the technical field of a small current line selection method using wavelet analysis, in particular to a small current line selection method using wavelet analysis. Background technique [0002] Existing line selection technologies only use part of the useful information of faults, so they all have certain limitations and cannot be applicable to all fault situations. In the past three years, the research on line selection for small current grounding faults has set off a climax again. Scholars at home and abroad have introduced wavelet analysis, Prony method, ANN method, information fusion, fuzzy methods, etc. into small current grounding fault protection. However, if you rely too much on mathematical analysis tools and ignore the thorough analysis of the fault characteristics itself, the solution to the problem is tantamount to sacrificing the basics. The current line selection device uses zero-sequence voltage to start the line...

AI Technical Summary

Problems solved by technology

However, if you rely too much on mathematical analysis tools and ignore the thorough analysis of the fault characteristics itself, the solution to the problem is tantamount to sacrificing the basics. The current line selection device uses zero-sequence voltage to start the line selection program, and many single-phase ground faults It is a gradual process. The zero-sequence voltage exceeds the limit after the initial transient process of the fault occurs for a period of time. At this time, the recorded waveform does not meet the premise of fault transient signal line selection.

In addition, only one line selection increases the possibility of misselection. Therefore, an improved technology is urgently needed to solve this problem in the prior art

Images