Single-phase grounding fault line selection method based on discrete orthogonal S transform and information divergence

Abstract

The invention discloses a single-phase grounding fault line selection method based on discrete orthogonal S transform and information divergence. The method includes the following steps that: voltagecollecting devices are installed on lines respectively so as to collect the transient voltage signals of each feeder line during a line fault; a data processing module is connected with the voltage collecting devices and converts the transient voltage signals into zero-mode voltage components; the data processing module sends fault starting signals to an upper computer, and a zero-sequence currentcollecting module installed on the lines collects the zero-sequence current signals of each feeder line and sends the zero-sequence current signals to the upper computer, discrete orthogonal S transform is performed on the zero-sequence current signals, so that the information divergence of each feeder line is obtained, a line with the largest information divergence is a single-phase grounding fault line. With the method of the invention adopted, the information divergence is solved through initial-half-wave zero-sequence current parameters, so that the selection of a single-phase grounding fault line in power distribution lines can be realized; the capacity of the discrete orthogonal S transform to divide the frequency bands of the transient signals and the capacity of the information divergence to distinguish the small differences of the signals are comprehensively considered, and therefore, the reliability of line selection is improved.

Description

technical field [0001] The invention belongs to the technical field of power grids, in particular to a single-phase ground fault line selection method based on discrete orthogonal S transform and information divergence. Background technique [0002] In my country's 6-66kV medium and low voltage distribution network, most of them adopt the operation mode of ungrounded neutral point or resonant grounding, collectively referred to as small current grounding system. Among distribution network faults, single-phase ground faults have the highest probability of occurrence, accounting for more than 80% of the total. After a single-phase metallic grounding occurs in the distribution network system, the fault phase-to-ground voltage is zero, and the non-fault phase voltage rises to the line voltage. The three-phase line voltage is still symmetrical and does not affect the load power supply. The relevant regulations allow the system to run for 2 hours with a fault. Therefore, it must ...

AI Technical Summary

Problems solved by technology

Although various line selection algorithms have certain line selection accuracy, there are inevitably action dead zones

Therefore, the single line selection method is increasingly unable to meet the requirements of single-phase fault line selection in the distribution network.

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