高速列车接触器非线性退化模型建立及寿命预测

The establishment of non-linear degradation model and life prediction of high-speed train contactor

高速列车电磁接触器的可靠性直接关系到列车的安全可靠运行,合理优化接触器更换周期不仅确保列车安全运行,而且降低检修与更换成本。该文对具有高可靠性的接触器进行加速试验设计,通过失效机理分析,选取超程时间作为特征参数表征接触器性能退化;并选取超程时间退化量作为失效判断特征物理量,基于非线性Wiener过程建立寿命预测模型。提出极大似然估计结合变步长遗传退火算法的方法对模型参数进行估计,计算出接触器剩余寿命分布的概率密度函数。通过加速模型将试验数据映射至常规工况后对3种寿命预测模型的拟合结果进行对比分析,结果表明基于幂函数非线性Wiener模型对接触器剩余寿命预测效果最佳,最后通过误差分析证明该预测方法的准确性符合工程应用。

The reliability of electromagnetic contactor in high-speed train is directly related to the safe and reliable operation of the train. Reasonable optimization of contactor replacement period not only ensures the safe operation of trains, but also reduces the cost of maintenance and replacement. In this paper, based on the acceleration theory, the contactor with high reliability is designed for acceleration test. Through the failure mechanism analysis, the super-path time is selected as the characteristic parameter to represent the contactor performance degradation. Super-path time degradation is selected as the characteristic physical quantity of failure judgment, and prediction models of residual life are established based on the nonlinear Wiener process.The maximum likelihood estimation method and the variable step size genetic annealing algorithm are proposed to estimate the model parameters, and the probability density function of the contactor residual life distribution is calculated. The results show that the nonlinear model based on the power function has the best prediction effect on the residual life of contactor. Finally, the accuracy of the prediction method is proved to be in line with the engineering application by error analysis.