Fault arc detection method and protection device adopting same

Abstract

The invention discloses a fault arc detection method which comprises the following steps of: sampling a current signal to acquire a sampling signal, then separating a high-frequency part from the sampling signal, identifying electric arcs by detecting the energy mutation of the high-frequency part and recording the appearance frequency of the electric arcs, and finally identifying a fault arc by detecting the frequency of the electric arcs. By utilizing the characteristic that the fault arc waveform contains high-frequency disturbance as a judgment condition for identify the electric arcs, the method effectively detects the alterative-current resistant load and the direct-current fault arc. The invention also discloses a protection device adopting the method, which can effectively recognize various fault arcs and takes corresponding protection measures.

Description

technical field [0001] The invention belongs to the field of circuit protection equipment, and in particular relates to a method for detecting fault arcs in a power distribution terminal system and a protection device using the method. Background technique [0002] Electrical lines and equipment in the house, such as: electrical wiring, sockets, wires inside household appliances or power lines of electrical appliances, etc., due to long-term overload operation, or poor electrical connections, etc., the insulation layer of the wires is aging , the insulation effect is reduced, or the insulation layer is damaged, a fault arc may occur. Arc sparks ignite the wiring and cause a fire. Currently commonly used circuit protection devices such as fuses and ground fault circuit interrupters cannot effectively detect fault arcs and form open circuit protection. AFCI (ArcFault Circuit Interrupter) technology is the latest circuit protection technology, which can provide arc fault prot...

AI Technical Summary

Problems solved by technology

Because, most of the AFCI detection methods and protection circuits now judge whether the derivative of the current waveform (di / dt, that is, the steepness of the waveform) or the flat shoulder of the arc, the asymmetry of the positive and negative half waves and other characteristics exceed the set threshold and Whether the accumulated arc cycle exceeds the threshold value is used to identify the fault arc current; however, for the automobile 42v DC power supply arc, or the load is resistive AC arc, such as Figure 7 , Figure 8 As shown, the flat shoulder of the arc, the positive and negative half-wave asymmetry and other characteristics are not very obvious, which exceeds the traditional AFCI detection method and the fault judgment principle of the protection circuit, so the arc protection device cannot operate correctly and effectively Detects AC resistive loads and DC fault arcs

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