考虑ESR老化的支撑电容寿命评估方法研究

Life Evaluation Method of DC-Link Capacitor Considering ESR Aging

文中以高速列车的金属化薄膜支撑电容为研究对象,研究了一种考虑ESR老化及任务剖面的支撑电容寿命评估方法。首先从薄膜电容的物理结构及失效机理出发,分析了电容失效过程中的退化特征;然后对薄膜电容电应力、热应力进行了探讨;最后结合某线路的实车空载工况的测试数据,基于经验寿命模型、线性累积损伤理论以及等效串联电阻ESR的老化模型对支撑电容的寿命评估方法进行了分析。研究结果表明,随着运行年限的增长,ESR的老化会导致功率损耗以及热点温度的明显增加,从而导致电容的寿命损伤率逐步加快。

This paper takes the metallized film DC-link capacitors commonly used in high-speed trains as the research object,a DC-link capacitor lifetime evaluation method considering ESR aging and mission profile is studied based on the existing theory and research foundation.Firstly,starting from the physical structure and failure mechanism of film capacitors,the degradation characteristics of the capacitor failure process are analyzed;then the electrical stress and thermal stress of film capacitors are discussed;Finally,combined with the actual train test data of a certain line,the lifetime of the DC-link capacitor is evaluated based on the empirical life model,the linear cumulative damage theory and the aging model of the equivalent series resistance ESR.The research results will provide references for reducing the maintenance cost of traction converters and promote the optimization of high-speed train maintenance procedures.