High-precision DC power distribution system insulation resistance monitoring circuit, detection device and monitoring method

Abstract

The invention discloses a high-precision DC power distribution system insulation resistance monitoring circuit, a detection device and a monitoring method. The detection circuit comprises a measurement resistance network and a voltage measurement circuit. The measurement resistance network comprises a first variable resistance unit and a second variable resistance unit which are sequentially connected in series between the positive electrode and the negative electrode of the direct-current distribution power supply, a first switch K1 unit which is connected in parallel with the first variable resistance unit, and a second switch unit which is connected in parallel with the first variable resistance unit; and the voltage measurement circuit is connected with a voltage value measurement circuit connected between the positive electrode and the negative electrode of the direct-current distribution power supply and the ground. When the insulation resistance is changed, the resistance value of the measurement resistance network can be adjusted to track the change of the insulation resistance in real time and always keep about two times of the insulation resistance, so that the insulation level of the whole system cannot be reduced by the measurement circuit, and the monitoring precision of the insulation resistance can be improved.

Description

technical field [0001] The invention relates to a high-precision DC power distribution system insulation resistance monitoring circuit, a detection device and a monitoring method. Background technique [0002] In low-voltage DC power distribution systems, especially in road DC long-distance power supply systems, due to the harsh working conditions of cables and converters, vibration, corrosion, changes in temperature and humidity, etc., may cause rapid aging of lines and other insulating materials or even insulation. Damaged, endangering personal and equipment safety. [0003] At present, there are many methods of insulation monitoring technology for DC systems in power plants, substations, electric vehicles, etc., but there are some shortcomings, such as the low sensitivity of the relay detection method, and the balanced bridge method cannot accurately and timely alarm when the insulation of the positive and negative poles is reduced at the same time. , the AC signal injec...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a high-precision DC power distribution system insulation resistance monitoring circuit, detection device and monitoring method to solve the problem that the current monitoring means cannot guarantee the monitoring accuracy when the insulation resistance changes

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