高压动力电池组绝缘性能的实时监测研究

摘要

This paper proposed an active insulation detection method into which low-frequency AC signal was injected. And the method was partitioned into two detection stages:fault detection and insulation resistance calculation.In the fault detection stage,by measuring the “measurement resistance”voltage and then calculating the positive-negative parallel resist-ance value,the insulation resistance fault status of the insulation resistance can be determined.In the insulation resistance calculation stage,by disconnecting the load circuit and the AC signal source and then respectively connecting two resistors in parallel with positive and negative insulation resistance,two resistors terminal voltage can be measured and the positive and negative insulation resistance values can be calculated.Simulation results show that the failure rate of false positives is less than 2.1 5% of fault detection,and it can basically achieve a function of real-time detection in the insulation resistance detec-tion by injecting the low-frequency AC signal.%传统的绝缘电阻监测方法不具备实时检测的功能，特定条件下无法监测，且抗干扰能力差。具有一定的局限性。本文在分析传统绝缘电阻监测方法的基础上，提出一种注入低频交流信号的有源式绝缘电阻监测方法，基本实现了绝缘电阻的故障实时监测.该检测方法分为两个阶段：故障检测、绝缘电阻计算。其中，故障检测：通过测量“测量电阻”两端电压，计算出正、负绝缘电阻的并联电阻值，并由此判断绝缘电阻故障状态；检测出绝缘电阻故障后，进行绝缘电阻的精确测量：断开负载、交流信号源，分别与正负极绝缘电阻并联接入两个电阻并测量其两端电压，计算出正负极绝缘电阻值。仿真结果表明，故障误报率小于2.15%，基本实现了绝缘电阻的故障实时监测。这项技术能够有效保证微电网蓄电池储能电站的绝缘性能，一旦事故发生，能够及时的发现故障，排除隐患，继续安全、稳定的运行。因此对高压电池组在实际生产中有较大的应用价值和意义。