电动汽车绝缘电阻检测方法分析及优化

Analysis and Optimization of Insulation Resistance Detection Method for Electric Vehicle

为了提高电动汽车绝缘电阻检测方法的速度和检测结果的精度,提高车辆高压安全性,对比分析了常见的电动汽车动力电池及高压系统的绝缘电阻主动检测和被动检测方法的检测原理和优、缺点,讨论了绝缘电阻检测精度的影响因素,并指出提高检测精度的措施,最终开发出了一种集成式的电动汽车绝缘电阻在线检测方法。结果表明:绝缘电阻主动检测方法可以识别到正、负双侧同时发生绝缘失效的工况并计算出绝缘电阻值,但其耗时较长;绝缘电阻被动检测方法可以实时判断车辆绝缘状态,但无法识别正、负两侧同时发生绝缘失效的情况,且无法准确检测出绝缘电阻值;改进后的集成式绝缘电阻检测方法可以兼顾车辆正常状态和发生绝缘故障时的绝缘电阻检测结果的精度,提高了主动检测方法的精度,进而提高了车辆的高压安全性能。

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.