Atom sparse evidence fusion-based adaptive fault line selection method of small current grounding faults

Abstract

The invention relates to an atom sparse evidence fusion-based adaptive fault line selection method of small current grounding faults. The method comprises the following steps: firstly, zero sequence current of each line is decomposed by a sparse decomposition method to obtain four optimum atoms, correlation coefficient between the four optimum atoms of each branch line and the optimum atom 1 is calculated by a correlational analysis method, and three atoms which have the highest correlation to the optimum atom 1 are selected as evidence atoms and the three atoms are sorted according to energy from large to small; secondly, energy entropy of each evidence atom is calculated, and an ascertainable fault measure value of each evidence atom is solved by an ascertainable fault measure function; thirdly, the ascertainable fault measure function is corrected to obtain a fault belief function of each evidence atom, and fault belief degree of each evidence atom is solved; and finally, each evidence fault belief degree value is fused to obtain each line fault comprehensive belief degree, a line corresponding to the maximum fault comprehensive belief degree value is selected as a fault line, and a line selection result is output.

Description

technical field [0001] The invention relates to an adaptive line selection method for small current grounding faults based on atomic sparse evidence fusion, and belongs to the technical field of power system fault line selection. Background technique [0002] At present, the problem of fault line selection for small current grounding systems has not been well resolved. When a single-phase ground fault occurs, the transient signal features are abundant, which makes the analysis method based on the transient signal widely concerned. Commonly used transient signal fault analysis methods include: transient energy method, S transform, Prony algorithm , correlation analysis, wavelet decomposition, empirical mode decomposition, etc. [0003] The transient energy method is used for fault line selection. When a large resistance grounding fault occurs, due to the compensation effect of the inductive current of the arc suppression coil on the instantaneous zero-sequence current of the...

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Problems solved by technology

[0002] At present, the problem of fault line selection for small current grounding systems has not been well resolved

[0005] (1) Trying to use limited basis functions to represent a wide variety of power fault signals, the feature extraction process is not adaptive, resulting in unexplainable decomposition items, which is very unfavorable for subsequent fault analysis and identification

[0006] (2) When the existing signal processing methods establish the mathematical model of the fault signal, they all assume that the characteristic components in the fault signal continue to exist, but the characteristic components in the actual fault signal do not have this characteristic. Obviously, this assumption is not appropriate

[0007] (3) The existing signal processing methods are insufficient in the effective storage of fault characteristic data in the era of "big data"

[0009] In addition, for fault line selection criteria, a single line selection criterion often cannot cover all grounding conditions, and it is difficult to fully adapt to various grid structures and complex fault conditions.

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