城轨列车车载超级电容寿命预测研究

Life prediction of vehicle supercapacitors for urban rail trains

城轨列车运行过程中,会对储能系统进行充放电,储能系统的超级电容组承受着周期性循环的结温波动,结温频繁变化会损伤超级电容,是列车储能系统中最易发生故障的器件之一。为了在线计算超级电容的结温状况,首先建立等效热网络模型;然后将热模型获得的结温曲线通过实时雨流计数法提取结温特征,结合所提寿命预测模型实现超级电容组的寿命预测。另外,以三维图的形式展示各平均温度和温度波动条件下超级电容组的循环寿命,为预测更多工况条件下超级电容组的寿命提供参考,以便进一步提高储能系统的可靠性和安全性。

The energy storage system of the urban rail train is charged and discharged during operation. The supercapacitor banks of the energy storage system are subject to cyclical fluctuations in the junction temperature. Frequent fluctuation of junction temperature in periodic cycle can damage the supercapacitor, which makes the supercapacitor component one of the most vulnerable devices in train energy storage system. In order to calculate the junction temperature of the supercapacitor online, the equivalent thermal network model was established firstly. Then the junction temperature curve obtained by the thermal model was extracted by real-time rainflow counting method, and combines with the proposed life prediction model, realizing life prediction of supercapacitor banks. In addition, the cycle life of the supercapacitor group under different average temperature and temperature fluctuation conditions was shown in the form of a three-dimensional graph, which provides a reference for predicting the life of the supercapacitor group under more working conditions, so as to further improve the reliability and security of the energy storage system.