动力锂电池荷电状态估算的改进方法

为了解决传统安时-开路电压法荷电状态(state of charge,SOC)初值SOC_0误差大,忽略了估算过程中温度等影响因素对估算精度的影响等问题,提出了改进的安时积分-开路电压法:根据不同温度、循环使用次数下的实验数据,拟合出SOC与开路电压(open circuit voltage,OCV)、温度、使用次数的函数关系,从而获取准确的SOC_0;结合实验分析温度、放电倍率、使用次数对于安时积分的影响,并对其进行修正和优化。实验表明,改进的安时-开路电压法可将估算精度提高至97%。

Improved SOC Estimation Method of Power Lithium Battery

In order to solve the problem that the large error in the SOC0 obtained by the traditional ampere-hour-integral and open-circuit-voltage method, and the influence of temperature and other influencing factors on the estimation accuracy is neglected in the estimation process, this paper proposes an improved ampere-hour-integral and open-circuit-voltage method: According to the data with different temperatures and cycles, we can get the function between SOC and OCV, temperature and cycles, and accurate initial value of SOC can be given. The influence of temperature, discharge rate and cycles on ampere-hour-integral is analyzed combining experimental data. Experiments have shown that this method can increase the accuracy of estimation to 97%.