Detection circuit and power supply circuit

Abstract

An embodiment of the application provides a detection circuit and a power supply circuit, relates to the field of power, and can detect a ground resistance of a cable on-line in a power supply systemhaving a neutral ground point. The solution is that the detection circuit comprises a variable voltage circuit and a current measuring circuit, wherein the variable voltage circuit comprises a first voltage source and a second voltage source, one end of the first voltage source is grounded through the current measuring circuit and the other end is used for connecting a first cable, the first cableis connected to the negative pole of a first diode in the power supply circuit, the positive pole of the first diode is connected to the positive output end of the power supply circuit, and the firstvoltage source is used to make the output current of the positive output end change to zero; one end of the two voltage source is grounded through the current measuring circuit and the other end is used for connecting a second cable, the second cable is connected to the positive pole of a second diode in the power supply circuit, the negative pole of the second diode is connected to the negativeoutput end of the power supply circuit, and the second voltage source is used to make the output current of the negative output end change to zero. The embodiment of the application is used for measuring ground resistances.

Description

technical field [0001] The embodiments of the present application relate to the field of electric power technology, and in particular, to a detection circuit and a power supply circuit. Background technique [0002] With the widespread use of power cables, the detection of the health status of the cables at the power supply end and the equipment end is becoming more and more important. Sudden power outages and leakage events caused by cable faults often pose serious threats to life and property safety, and cause adverse social impacts. Conduct regular health checks on cables in engineering, and early detection of faults is an important guarantee for safe operation of cables. [0003] In the early days, due to technical reasons, most of the off-line methods were used to detect the health status of cables, that is, regular power outages for maintenance, which would have a greater impact on normal work and life, and it was also difficult to make early judgments on cable faults...

AI Technical Summary

Problems solved by technology

In a power system with a floating power supply, the leakage resistance of the cable can be detected by using bridge balance, DC superposition method or AC injection; while in a power system with a power supply circuit with a neutral ground point, these methods are usually Unable to detect the resistance of the cable to ground

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