【摘要】 为提高新能源汽车的整车动力性、经济性以及安全性,需要准确估计动力电池的SOC值。因电池SOC存在非线性特性且受许多因素影响,提高准确性的关键在于建立准确的模型并与适当的估算算法相结合。首先对三元锂离子电池建立了二阶RC等效电路模型,之后采用平方根无迹卡尔曼滤波法与改进的安时法相结合,综合考虑了充放电倍率、温度以及循环次数的影响。通过Simulink仿真,分别在SOC初值不准确和因老化引起的容量衰减的条件下对比该算法与传统安时法,仿真结果显示,参数扰动造成的估算误差得到了快速的修正。改进的平方根无迹卡尔曼滤波算法具有较高的鲁棒性及SOC估计精度。更多还原

【Abstract】 In order to improve the power performance,the economy and safety of new energy vehicle,the SOC of power battery should be estimated accurately. Due to the nonlinear characteristics of the battery SOC,which affected by many factors,the key for improving its accuracy is to establish an accurate model and combine with the appropriate estimation algorithm. First,we established a second-order RC equivalent circuit model for ternary lithium-ion battery,then combined the square root unscented Kalman filter( SRUKF) with the improved current integral method,and comprehensively considered the influence of the battery charge and discharge rate,temperature and cycle times.Compared this algorithm with traditional current time integral under the condition of inaccurate SOC initial value and capacity fading caused by aging through Simulink simulation,the simulation results show that the estimation error caused by parameter perturbation is rapidly corrected. The improved square root unscented Kalman filtering algorithm has higher robustness and SOC estimation accuracy.更多还原