电动汽车动力电池温度在线估计方法

电动汽车动力电池内部复杂的电化学反应容易受到环境温度的影响,造成电池功率和容量特性的衰减。为了准确估计电池温度变化,提出基于热平衡方程的电池温度在线估计方法,生热部分考虑可逆的熵变生热和不可逆的过电势生热对总体生热的影响,散热部分考虑电池与外界环境的热交换。采用一阶等效电路模型结合扩展卡尔曼滤波实时在线估计模型参数,并利用热平衡方程获得的电池温度递推公式,根据前一时刻电池温度估计当前时刻电池温度。采用联邦城市行驶工况(FUDS)实验对所提方法进行验证,结果表明,所提出的电池温度在线估计方法在电池运行过程中能够实时准确估计电池温度,估计误差在1℃以内。

Online Temperature Estimation Method for Electric Vehicle Power Battery

The complex electrochemical reaction inside the power battery of electric vehicle tends to be influenced by the environment temperature,which causes the attenuation of the power and capacity.In order to estimate accurately the temperature of battery,this paper presents the battery temperature online estimation method based on the thermal balance equation.The heat generation considers the reversible entropy change and irreversible overpotential,besides,the heat exchange is between battery and the external environment.The one order equivalent circuit model combined with extended Kalman filter in real-time is used to estimate model parameters online,and the battery temperature recursive formula is obtained using thermal balance equation.The battery temperature of the current sample time is estimated according to that of the last sample time.The proposed method is verified by federal urban driving schedule(FUDS) test.The proposed method can estimate battery temperature in real time,and the estimation error is within 1 ℃.