关键词: 内部温度, 热管理, 可变参数模型, 扩展卡尔曼滤波

Abstract: 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．

Key words: internal temperature, thermal management, variable parameter thermal model, extended Kalman filter