动力电池组绝缘电阻检测与故障定位

动力电池组在正常运行中需要符合绝缘安全性要求,以保障高压供电系统的正常运行。针对当前动力电池组绝缘电阻检测精度低、可靠性差、无法定位电池组内部绝缘故障点等问题,提出一种改进的绝缘电阻在线检测与故障点定位方法。该方法结合平衡电桥和非平衡电桥进行测量,改进绝缘电阻计算方法,能快速、准确的实现动力电池组绝缘电阻检测,并可估计电池组内部发生绝缘故障的位置。根据改进测量方案,利用微控制器、光耦继电器、差分模数转换器、数字信号隔离、隔离电源等设计了检测系统硬件及软件,实现了绝缘电阻检测与故障点定位。实验测试表明,改进的检测方法和检测系统能够准确检测出绝缘电阻值,检测误差在5%以内,绝缘故障点定位准确,为动力电池组绝缘电阻检测与故障定位提供了一种实用的方法。

Insulation resistance detection and fault location for power battery pack

In order to ensure the normal operation of the high-voltage power supply system, the high-voltage power battery pack needs to meet insulation safety requirements during normal operation. An improved method for on-line detection of insulation resistance and fault point location is proposed to solve the problems of low accuracy and poor reliability of insulation resistance detection of power battery packs, and inability to locate the internal insulation fault location of the battery pack. This method combines balanced bridge and unbalanced bridge to measure, improves the calculation method of insulation resistance, can quickly and accurately realize the insulation resistance detection of power battery pack, and can estimate the location of insulation fault inside the battery pack. According to the improved measurement principle, the hardware and software of the detection system are designed using microcontrollers, optocoupler relays, differential analog-to-digital converters, digital signal isolation, isolated power supplies, etc., to achieve insulation resistance detection and fault location. Experimental test show that the improved detection method and detection system can accurately detect the insulation resistance value, the detection error is within 5%, and the insulation fault point is located accurately, which provides a practical method for the insulation resistance detection and fault location of the power battery pack.