Pulsating DC (direct current) aftercurrent protector and running method thereof

Abstract

The invention provides a pulsating DC (direct current) aftercurrent protector and a running method thereof. The protector comprises a switching device, a microprocessor, a zero sequence current transformer, an aftercurrent signal amplifying circuit and a power supply, wherein the output of the zero sequence current transformer is connected with the aftercurrent signal amplifying circuit; the output of the aftercurrent signal amplifying circuit is connected with the microprocessor; the switching device is connected with the microprocessor; the input of the power supply is connected with a power grid; and the output of the power supply and the microprocessor are connected with the switching device. The protector can distinguish the types of aftercurrent waveforms and adopts the different protective measures in accordance with the different types of the aftercurrent waveforms, thus improving the protection accuracy; and the protector is suitable for the aftercurrent protection of the power grid with different frequencies or can be used for realizing the accurate aftercurrent protection when the frequency of the power grid is changed, thus expanding the application occasions of the protector. The protector is simple in structure, small in volume and very low in power consumption.

Description

technical field [0001] The invention belongs to the field of electrotechnical technology, and the technical proposal relates to an automatic disconnection emergency protection circuit device which directly responds to unexpected changes deviated from normal electrical working conditions, specifically a pulsating DC residual current protector and its run method. Background technique [0002] The residual current protector is an important device in the low-voltage power grid, which plays an important role in preventing electrical fires and protecting people from electric shock. With the development of power technology, the application range of residual current protection technology is getting wider and wider, and the requirements are getting higher and higher. The current residual current protection technology is mainly developed for the sinusoidal residual current, and the protection technology is relatively mature. The AC type residual current protector used in daily life c...

AI Technical Summary

Problems solved by technology

A "type A leakage circuit breaker" disclosed in CN 101477926A realizes the detection of pulsating DC residual current through an analog circuit, and the protection accuracy is low; a "multifunctional leakage circuit breaker" disclosed in CN 101436496A adopts a dedicated chip M54123L, which cannot effectively Protection against pulsating DC residual current

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