High-voltage DC insulation detection system and detection method

Abstract

The invention relates to a high-voltage DC insulation detection system and detection method, and the system comprises two insulation resistance detection circuits, and each insulation resistance detection circuit comprises a DC power supply anode to-ground fixed arm, a DC power supply anode to-ground movable arm, a DC power supply cathode to-ground fixed arm, a DC power supply cathode to-ground movable arm, and a high-voltage optocoupler. A bridge arm of the detection circuit is made to be unbalanced by controlling switching connection or disconnection of the high-voltage optocoupler U1 and the high-voltage optocoupler U2, and insulation resistance values R + and R-of the to-be-detected high-voltage DC bus are calculated by reading voltage values of the analog-digital converter AD1 and theanalog-digital converter AD2. The system is small in size and powerful in function, two paths of insulation resistance can be detected at the same time, response is fast, and rapid changes can be detected in real time; lightning surge and leakage current are controllable, and the safety level is high; installation and use are convenient, and maintenance is easy; and the application prospect in the field of new energy high-voltage DC charging is wide.

Description

technical field [0001] The present invention relates to the technical field of new energy charging and swapping, in particular to fields such as insulation resistance detection of DC output terminals of DC charging piles, insulation detection of DC output terminals of vehicle-mounted chargers, and insulation resistance detection of DC output terminals of battery pack discharge; specifically, it relates to a A high voltage direct current insulation detection system and detection method. Background technique [0002] For high-voltage DC charging and discharging in the field of new energy, the environment for outdoor installation or vehicle use is relatively harsh, and the cable aging speed is fast. Once the cable ages, the insulation resistance value decreases, and flashover and short circuit breakdown are very likely to occur under high voltage and high current conditions, endangering the lives of users and causing serious property losses. In order to avoid serious accidents...

AI Technical Summary

Problems solved by technology

However, the bridge arm switch uses ordinary electronic relays. When the DC+ and DC- ground voltages change rapidly, because the ordinary electronic relays adopt mechanical opening and closing, the response speed is slow, and the insulation resistance cannot be detected in real time.

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