Resonant grounding system single-phase grounding fault line selection method based on spatial information entropy

Abstract

The invention provides a resonant grounding system single-phase grounding fault line selection method based on spatial information entropy, and relates to the technical field of power system relay protection. The resonant grounding system single-phase grounding fault line selection method based on the spatial information entropy comprises the steps of recording waves and extracting a transient low-frequency zero-sequence current sequence of each line of a distribution network; and carrying out symbol and digital conversion on the transient low-frequency zero-sequence current sequence under multiple time scales, generating a three-dimensional fault space after data verification, defining a spatial information entropy, and comparing entropy difference degrees to complete fault line selection. Compared with the prior art, the technical scheme has the advantages that when a single-phase high-resistance grounding fault occurs, correct line selection can be realized under the condition that a large amount of sampling data is distorted or lost without increasing extra construction cost and operation control difficulty; the spatial information entropy is defined to unfold the single-phase high-resistance grounding fault features in a three-dimensional space domain, so that the fault features are more stereoscopic and richer, and symbol sequence difference description is more accurate.

Description

technical field [0001] The invention relates to the technical field of power system relay protection, in particular to a line selection method for a single-phase grounding fault of a resonant grounding system based on spatial information entropy. Background technique [0002] In the prior art, there are two types of grounding methods for the neutral point of the medium and low voltage distribution network: ungrounded and resonant grounding. With the continuous expansion of the distribution network scale, the system capacitance current also increases, so the resonance grounding method is often used to reduce the short-circuit current. However, because the grounding method introduces the compensation current of the arc suppression coil, when the single-phase grounding fault occurs in the system, the amplitude of the fault information is small, and it is difficult to identify the faulty line. Not only that, there are many distribution network lines, flexible operation methods,...

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Problems solved by technology

[0005] The purpose of the embodiment of the present invention is to provide a single-phase grounding fault line selection method for a resonant grounding system based on spatial information entropy, so as to solve the single-phase grounding fault in the resonant grounding system without increasing additional construction costs and operational control difficulties When a large amount of data distortion affects the correct rate of line selection

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