Method for detecting and monitoring high-resistance ground fault by online zero setting and test device thereof

Abstract

The invention discloses a method for detecting and monitoring high-resistance ground fault by online zero setting and a test device thereof. A direct current (DC) sawtooth wave signal is applied to a fault equipment line; when at a low level, the signal is in a zero setting period, and when at a high level, the signal is in a test period; after a DC current signal receiver is clamped on the faulty line, the signal is received; DC online zero setting is performed in the zero setting period of the signal, and online test is performed in the test period of the signal; and therefore, the ground fault point (or line mixing, short circuit) can be determined directly without turning off the electric equipment (power supply), throwing line or releasing line bundle; moreover, the test device comprises a DC sawtooth wave signal generator and a DC current signal receiving tester, wherein the DC sawtooth wave signal generator can generate the DC sawtooth wave signal; an intelligent control module, a wireless transceiver and a wire signal transceiver module are arranged in each of the DC sawtooth wave signal generator and the DC current signal receiving tester; and the test method can be automatically realized. Through the method and the device, the online zero setting is performed in the zero setting period when the DC sawtooth wave is at low level and the online test is performed in the test period when the DC sawtooth wave is at high level after line clamp, and therefore personal error and DC signal shift are thoroughly eliminated.

Description

technical field [0001] The invention relates to a method for detecting a high-resistance grounding circuit fault through a waveform generator and a waveform receiver and the improvement of its device structure, especially a method for online zero-setting detection and monitoring of a high-resistance grounding fault and a testing device thereof. Background technique [0002] Equipment (power supply) grounding (or mixed line, short circuit) fault is a great hidden danger affecting the normal use and safety of equipment. There are currently known ways to find such faults as follows: ①Low-frequency signal injection method - After a ground fault occurs in the equipment (power supply), a low-frequency signal is injected between the grounded power supply and the ground, and the low-frequency current flows out from the signal generator and passes through The grounding point is returned from the ground, and the clamp-type current probe is used to detect point by point, trace the dire...

AI Technical Summary

Problems solved by technology

In the case of high-impedance faults, the influence of distributed capacitance cannot be overcome

④Phase method - On the basis of the frequency conversion detection method, a high-frequency signal is modulated to distinguish resistive and capacitive currents through phase changes. When a high-impedance fault occurs, the influence of distributed capacitance cannot be overcome.

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