Device for detecting resistive and capacitive currents of voltage-limiting surge protector

Abstract

The invention relates to a device for detecting the resistive and capacitive currents of a voltage-limiting surge protector. The device includes a commercial power sampling circuit, a leakage currentsampling circuit, a phase comparison circuit, a display drive circuit, and a state display circuit. The commercial power sampling circuit is connected with a commercial power supply line, and is usedfor sampling commercial power voltage. The leakage current sampling circuit is connected with a surge protector, and is used for sampling leakage current voltage. The input end of the phase comparisoncircuit is in circuit connection with the commercial power sampling circuit and the leakage current sampling circuit, and the phase comparison circuit is used for comparing the phases of the commercial power voltage and the leakage current voltage to get an output voltage. The input end of the display drive circuit is connected with the output end of the phase comparison circuit, and the output end is connected with the state display circuit. The display drive circuit is used for analyzing the output voltage of the phase comparison circuit and driving the state display circuit to display state. The resistive and capacitive currents of a voltage-limiting surge protector can be automatically detected, and the working condition of the voltage-limiting surge protector can be monitored in realtime.

Description

technical field [0001] The invention relates to a device for automatically detecting resistive and capacitive currents of a voltage-limiting type surge protector, which belongs to the field of lightning science and technology. Background technique [0002] The core device of the voltage-limiting surge protector is the zinc oxide varistor. The zinc oxide varistor is under the action of the line voltage for a long time. Due to the fluctuation of the line voltage and the effect of overvoltage, it will deteriorate and age. The deterioration and aging of the zinc oxide varistor lead to an increase in the leakage current, mainly due to the increase in the resistive current of the zinc oxide varistor. The reason why the resistive current becomes larger is that the reference voltage of the zinc oxide resistor and the insulation resistance become smaller. The leakage current of the voltage-limiting surge protector becomes larger, and the main component of the leakage current is resi...

AI Technical Summary

Problems solved by technology

The leakage current of the voltage-limiting surge protector becomes larger, and the main component of the leakage current is resistive current. The resistive current will cause the surge protector to heat up, and it will cause overheating damage under long-term action, resulting in a short circuit of the power supply line, making the power supply The system cannot operate normally, trips, power failures, and even fire accidents occur

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