Complicated residual current detection method based on magnetic core working state switch

Abstract

The invention relates to a residual current detection method using magnetic core working state switch. Since the DC leakage signal does not fluctuate and the coil cannot induce the signal, it is necessary to superimpose the signal on an alternating signal. The method provided by the invention uses a chip to realize two states of the positive and negative square waves of the H-bridge circuit to achieve an external magnetic field, the bidirectional saturation excitation square wave signal enters the bidirectional saturation region of the magnetic core, the different characteristics are generatedby the DC in different regions of the magnetization curve, and the DC leakage detection and protection are completed by extraction and distinguishing with an algorithm. The AC leakage itself has fluctuations and works in the linear region of the magnetic core, so that the coil can directly sense signals including 50Hz, high-frequency AC 400Hz, 1kHz, 20kHz, 150kHz, etc. At this time, the coil is no excitation signal, and the data are extracted and calculated through the algorithm to complete AC leakage detection and protection. Three states of forward excitation, reverse excitation and no excitation are switched to complete the detection of complex residual current.

Description

technical field [0001] The invention belongs to the field of electric leakage detection, and mainly relates to a method for detecting complex residual current by switching the working state by using the different responses of the magnetic core to the AC and DC residual current in different regions of the magnetization curve Background technique [0002] With the development of the economy, the power industry is developing rapidly, and the scale of various household appliances is becoming more and more abundant. How to ensure the safety of households' electricity consumption becomes particularly important. It is necessary to detect various complex wave signals, including AC, DC, and high-frequency signals. etc.; AC residual current is extremely harmful to the human body, 50mA / s is ventricular fibrillation, and with the increase of power consumption types, the problem of DC residual current detection has also become more important. The current DC current is widely used, includi...

AI Technical Summary

Problems solved by technology

[0003] At present, the market is aimed at B-type and higher-standard residual current detection products. Electromagnetic current transformers, Hall current sensors, and magnetic modulation current transformers are mostly used for residual current detection. defects such as full residual current waveform coverage, therefore, it is necessary to develop a method that can effectively solve both problems

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