Analysis and Optimization of Insulation Resistance Detection Method for Electric Vehicle

In order to improve the speed and accuracy of the insulation resistance detection method of electric vehicle, and improve the high voltage safety of vehicle. The detection principles, advantages and disadvantages of the common active detection and passive detection methods of insulation resistance of electric vehicle power battery and high voltage system were compared and analyzed. The influence factors of insulation resistance detection accuracy were discussed, and the measures to improve the detection accuracy were pointed out. Finally, an integrated on-line detection method of electric vehicle insulation resistance was developed. The results show that the active detection method of insulation resistance can identify the insulation failure of positive and negative sides at the same time and calculate the insulation resistance value, but it takes a long time. The passive detection method of insulation resistance can judge the vehicle insulation state in real time, but can not identify the insulation failure of positive and negative sides at the same time, and insulation resistance value can not be detected accurately. The improved integrated insulation resistance detection method can give consideration to the accuracy of insulation resistance detection results in normal state and insulation fault, improve the accuracy of active detection method, and improve the high voltage safety performance of vehicle.