基于线性Wiener过程的Ni-Cd蓄电池寿命预测

Life prediction of Ni-Cd battery based on linearWiener process

对动车组Ni-Cd蓄电池进行寿命预测,不仅可以提高蓄电池的安全性和可靠性,还可以降低动车组运营成本。为此,本文提出基于线性Wiener过程的寿命预测方法,该方法不仅适用于单调和非单调变化的退化系统,还具有良好的效果。首先,建立一元线性Wiener退化模型,利用最大期望(EM)方法估计得到模型未知参数,再得到蓄电池剩余使用寿命(RUL)及其分布。然后,利用Copula函数描述容量和能量的相关性,建立二元线性Wiener退化模型,利用马尔科夫链蒙特卡洛(MCMC)方法估计得到模型未知参数,得到蓄电池RUL及其分布。实验结果表明,基于容量和能量的二元线性Wiener退化模型比一元线性Wiener模型具有更高的精确度。

Predicting the life of Ni-Cd battery for electric multiple units(EMU)can not only improve the safety and reliability of battery,but also reduce the operating costs of EMU.For this reason,a life prediction method based on linear Wiener process is proposed,which is suitable for both monotonic and non-monotonic degraded systems with accurate results.Firstly,a unary linear Wiener degradation model is established,and the parameters of the model are estimated by using the expectation-maximization algorithm(EM).With the established model,the remaining useful life(RUL)of Ni Cd battery and its distribution are obtained.Then based on the unary Wiener process degradation model,the correlation between capacity and energy is analyzed through Copula function to build a binary linear Wiener degradation model,where its parameters are estimated using Markov Chain Monte Carlo(MCMC)method.Finally,according to the binary Wiener process model,the battery RUL and its distribution are acquired.The experimental results show that the binary linear Wiener degradation model based on capacity and energy possesses higher accuracy than the unary linear wiener process degradation model.