基于开路电压预测的SOC估算方法

SOC estimation method based on the prediction of open-circuit voltage

为了得到电池的荷电状态(SOC),提高其测算精度,更广泛适用于电动汽车能量管理系统,通过对锂电池进行恒流充、放电实验方法得到SOC和锂电池开路电压的曲线关系,然后将放电后的电池充分静置得到电压自恢复曲线的分析,再结合锂电池等效电路模型,应用Matlab拟合出锂电池开路电压曲线,从而推导出开路电压的计算公式,完成开路电压的预测。最后将实验结果与理论分析进行了对比,进一步验证了理论和仿真建模的正确性。这种方法克服了开路电压法测量时间长的缺点,能够准确地计算SOC,对电池管理系统有重要意义。

In order to get the state of charge（SOC）of the battery and improve the accuracy of calculation,suiting to the energy management system of electric vehicle more widely,the lithium battery curve of the open circuit voltage（UOCV）and SOC is obtained by charging and discharging battery with constant current,as well as the curve of self-recovery after discharging.The formula for estimating the open-circuit voltage is based on Matlab software for curving fitting,which is combined with the equivalent circuit model of lithium battery.Then the open circuit voltage is predicted.The shortcomings of let-stand time is solved by using the method.By comparing the experimental results with theoretical analysis,the correctness of the theory and simulation models has been further verified.Experiment result shows that this algorithm can accurately estimate the SOC and has certain significance on the research of battery management system.