【摘要】 充电机是动车组直流供电系统的核心环节，而直流支撑电容是充电机中的关键元件，如何准确评估直流支撑电容的寿命状态对充电机的故障预测及修程修制的合理安排具有十分重要的意义。针对此问题，对动车组充电机直流支撑电容失效机理进行分析，研究不同失效模式对电容退化程度的影响及对应的失效判据；在此基础上，提出一种基于阿伦尼斯模型的电容双应力加速寿命模型；为验证所提模型的正确性，开展基于不同纹波电流和温度的加速寿命实验，通过加速寿命实验确定电容实际失效时间，其与电容双应力寿命模型计算所得的电容理论失效时间相比，误差小于8.7%,验证了所提电容双应力加速寿命模型的正确性。在此基础上，进一步提出动车组充电机直流支撑电容寿命评估方法，实现动车组充电机直流支撑电容在实际运营工况下寿命的准确评估。更多还原

【Abstract】 The battery charger is the core link of the DC power supply system of the electric multiple units(EMUs), and the DC capacitor is a key component of the battery charger. Accurate evaluation of the life state of the DC capacitor is of great significance to the fault prediction and reasonable maintenance process arrangement of the battery charger. Aiming at this problem, this paper studied the influence of different failure modes on the degree of capacitor degradation and the corresponding failure criteria by analyzing the failure mechanism of the DC capacitor of the battery charger. On this basis, a double-stress accelerated life model of the DC capacitor based on Arrhenius model was proposed. A series of accelerated life experiments were carried out based on different ripple currents and temperatures to verify the correctness of the proposed model. The errors between the actual failure time of the capacitor determined by accelerated life experiments and the theoretical failure time of the capacitor calculated by the double-stress accelerated life model are less than 8.7%, which verify the correctness of the proposed double-stress capacitive accelerated life model. Finally, a life evaluation method for the DC capacitor of the EMU battery charger was further proposed based on the double-stress accelerated life model for the DC capacitor, realizing the accurate life evaluation of DC capacitor of the EMU battery charger under actual operating conditions.更多还原