The safety of battery system is compromised by the abusive operation and aging, potentially resulting in the abnormal voltage levels. Rapid detection and accurate diagnosis of voltage fault are crucial for ensuring the safety of battery packs. A battery voltage fault diagnosis method is proposed by using the mutual information in this work, which can identify faulty cells timely. Specifically, the voltage of battery pack in an electric vehicle is collected, and the mutual information of voltages between each paired-cells is calculated. The presence of faulty cells disturbs the original distribution of mutual information. Therefore, the Ryan Joiner (RJ) test is used to judge whether the normal distribution of calculated mutual information or not. The interquartile test is used to detect the outliers. The faulty cell is diagnosed by matching the cell corresponding to the outliers. The defaults resulting from an internal short circuit and mechanical vibration are analyzed and diagnosed. The method can avoid misdiagnosis caused by the mutual influence between different faults. Furthermore, the fault diagnosis capability of presented method is discussed under various states of aged cells. The experimental results verify the effectiveness, robustness, model-free, and easiest-to-implement of the presented method.

中文翻译：

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基于互信息的电动汽车电池组电压故障诊断


滥用操作和老化会损害电池系统的安全性，可能导致电压水平异常。电压故障的快速检测和准确诊断对于保证电池组的安全至关重要。本文提出了一种利用互信息的电池电压故障诊断方法，可以及时识别故障电池。具体地，采集电动汽车中的电池组的电压，并计算每对电池之间的电压的互信息。有缺陷的单元的存在扰乱了互信息的原始分布。因此，采用Ryan Joiner（RJ）检验来判断计算出的互信息是否服从正态分布。四分位数检验用于检测异常值。通过匹配与异常值对应的单元格来诊断故障单元格。对内部短路和机械振动引起的故障进行分析和诊断。该方法可以避免不同故障之间相互影响而造成的误诊。此外，还讨论了该方法在老化电池的各种状态下的故障诊断能力。实验结果验证了该方法的有效性、鲁棒性、无模型且最容易实现。