【摘要】 围绕轨道交通牵引变流器内主回路功率器件的老化规律测试及其损伤评估方面开展研究。首先,针对既有开关器件的寿命模型无法反映续流二极管(FWD)对功率开关器件总体老化水平的加速效应这一问题,提出采用基于双向老化测试电流的老化试验方法,并在双向老化测试的结果分析过程中,提出带加权的修正最小二乘法以提高老化结果的数学拟合精度的解决方案,从而基于实验数据得到了对应的加速效应表达因子。提出功率开关器件中IGBT与FWD的电流重构方法,同时也给出了考虑电流传感器容错条件下的电流重构表达式,进而基于在线等效老化电流的辨识过程实现功率开关器件的在线老化水平评估,最终通过二阶灰色模型实现了功率开关器件的损伤预测。更多还原

【Abstract】 This paper aims at damage characteristic test and evaluation of a switching device in urban transit traction converter. A novel accelerated aging test with bidirectional aging test current is proposed, which enables the test results to relieve the acceleration effect of free-wheeling diode(FWD)on the service lifetime of the overall switching device. Such effect is expressed by an acceleration factor, whose value is calculated by fitting procedures. The weighted least squares method is proposed to improve the mathematical fitting accuracy of the aging results. The aging characteristic between cycling lifetime and aging current amplitude is given in an equation, which considers ambient temperature influence with an Arrhenius modifying factor. The paper builds an analytical model for IGBT and FWD currents observation, and then the aging current of switching device is obtained. The damage level is evaluated by the proposed fitted equation and finally damage increments at given time intervals are subjected to a high-order Gray prediction model, for final prediction.更多还原