锂电池内部温度的准确估计是实现电池安全可靠热管理的关键，为准确估计锂 电池内部温度，针对现有电池热模型中各热电参数的辨识误差对内部温度估计精度的影 响，文中提出基于简化可变参数热模型的锂电池内部温度估计方法． 通过对不同环境温度 下锂电池内部热容与外部热阻进行辨识，建立可变内部热容与外部热阻估计模型，同时对 模型机理进行分析，详细描述了外部环境对于内部热容和外部热阻的影响，并通过实验验 证了模型的可靠性;最后结合扩展卡尔曼滤波(EKF)算法，实现对内部温度的估计． 不同 温度梯度下的恒流放电实验与仿真结果证明，所建模型适用于不同环境温度下的锂电池 热模型，提高了内部温度估计精度．

The accurate estimation of the internal temperature of lithium battery is the key to realize the safe and re- liable thermal management of the battery． In order to accurately estimate the internal temperature of the lithium battery，considering the influence of the identification error of each thermoelectric parameter in the existing battery thermal model on the internal temperature estimation accuracy，a method for estimating the internal temperature of a lithium battery based on a simplified variable parameter thermal model was proposed． By identifying the internal heat capacity and external thermal resistance of lithium battery at different ambient temperatures，a variable inter- nal heat capacity and external thermal resistance estimation model was established to analyze the model mechanism， and the influence of external environment on internal heat capacity and external thermal resistance． The reliablity of the model was verified by experiments． Finally，the extended temperature Kalman filter (EKF) algorithm was used to estimate the internal temperature． The constant current discharge experiment and simulation results under different temperature gradients prove that the model is suitable for the lithium battery thermal model under different ambient temperatures，and it has improved the internal temperature estimation accuracy．