Arc fault detection method and protection device

Abstract

The invention relates to an arc fault detection method and a protection device. The arc fault detection protection device comprises a current transformer, an I/V conversion circuit, a rectifying circuit, an integral circuit and a microprocessor, wherein the I/V conversion circuit, the rectifying circuit, the integral circuit and the microprocessor are connected in sequence. The current transformer detects current signals of a protected circuit, current signals are converted into voltage signals through the I/V conversion circuit arranged at the secondary side of the current transformer, the voltage signals are sent into the rectifying circuit to be rectified through a voltage follower, wave signals obtained after rectification are provided for the integral circuit, the integral circuit provides the voltage level cumulant in a preset time period for the microprocessor, the microprocessor captures the periodical integral value through timing A/D conversion and stores the periodical integral value, the current waveform change of the protected circuit is detected through an arc fault detection algorithm, arc fault judgment is conducted, disturbance caused by arc fault, or caused by normal starting of a load or caused by power regulation can be effectively distinguished, mistaken disengagement actions of the device can be reduced, and reliability is higher.

Description

technical field [0001] The invention relates to the field of arc fault detection in low-voltage power distribution systems, in particular to an arc fault detection method and a protection device that are not easily disturbed by changes in normal operating current waveforms. Background technique [0002] With the rapid development of social economy and the continuous improvement of people's living standards, the degree of electrification is getting higher and higher, and the power consumption is also increasing. Electrical fire incidents occur more and more frequently, causing huge losses to personal and property. According to relevant statistics, fires caused by electrical causes top the list of all kinds of fires, accounting for about 30%. The occurrence rate of electrical fires and the property losses caused by them rank first among all kinds of fire causes, especially among these fires, serious and extraordinarily large electrical fires occur from time to time. Arc faul...

AI Technical Summary

Problems solved by technology

[0004] Although related products have been widely used abroad, which can detect and distinguish arc and normal load interference, false tripping still occurs

For example, dimmers, electric drills, vacuum cleaners, etc. generally generate the same number of arc events per half cycle during normal operation. tripping

And these conventional devices are often difficult to distinguish between certain load start-up, power regulation, shutdown and arc fault

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