Series fault arc detection method and system based on limited sampling data

Abstract

The invention discloses a series fault arc detection method and system based on limited sampling data, and the method comprises the steps of carrying out continuous sampling on a load current at a setsampling frequency, obtaining N pieces of sampling data as one frame of sampling data; based on the sampling data, calculating to obtain a plurality of virtual energy indexes; counting the maximum value, the minimum value, the mean value and the variance of the virtual energy index, and calculating a periodic fluctuation coefficient; and comparing the periodic fluctuation coefficient with a self-adaptive threshold value, and judging whether an arc fault occurs in the line where the load is located or not. The method has the beneficial effects that on the basis of the statistical information of the virtual energy indexes, a periodic fluctuation index, a dynamic threshold value, a fault judgment method and a dynamic threshold value updating algorithm are established; the periodic fluctuation index has good indication for the series arc fault, the index jumps to more than 3-8 times of the normal state when the fault occurs, and the fault and the normal working condition can be accuratelydistinguished.

Description

technical field [0001] The invention relates to the technical field of arc fault detection, in particular to a method and system for detecting arc faults in series based on limited sampling data. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Arc faults are generally high-temperature discharges caused by line aging, insulation damage or failure, loose connections, and poor contact. The series fault arc of the low-voltage power supply system has the characteristics of small loop current and strong fault concealment. Combustibles are a serious safety hazard. [0004] At present, current-based protection devices are widely used in power supply and distribution systems, which can be divided into two categories that act on phase current and act on residual current. When the effective value of the phase current or residual current exceeds th...

AI Technical Summary

Problems solved by technology

This kind of protective device can play a better protective role against faults and accidents such as overload, metallic short circuit, grounding and electric shock; but due to the current limiting effect of the load, the effective value of the series fault arc current is generally much smaller than the metallic short circuit and overload , the overcurrent release cannot operate reliably; while the series fault arc does not generate residual current, and cannot trigger the operation of the residual current release

It can be seen that the existing protection devices cannot detect the existence of series arcs in time, so that the fault arcs can be burned concealed for a long time, which is the main cause of serious electrical fires

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