基于充电方式的锂电池SOC 校准和估计方法

荷电状态(SOC)是动力锂电池的重要参数.针对安时法估计锂电池SOC存在累积误差,其他估计算法复杂度较高的问题,提出一种工程实用的SOC估计方法.该方法通过分析电池特性并结合安时法,建立了SOC初始值、总容量和累积误差的校准方法.通过建立终端电压与SOC之间的映射关系,利用恒流、恒压不同充电阶段的电池特性,实现了电池系统在一个放电周期内的SOC高精度估计.实验表明,该方法能够使得SOC的估计误差在5%以内.

Method to calibrate and estimate Li-ion battery state of charge based on charging method

The state of charge(SOC) is an important parameter of the power Li-ion battery. As there exists accumulation errors in the current integration method to estimate the SOC and some other methods are usually very complicated, a practical engineering method to calibrate the estimation of battery SOC is proposed. With the analysis of battery characteristics, some methods are established to calibrate the SOC initial value, the total capacity and the accumulated error by combining the current integration method. By establishing the relationship of the battery terminal voltage and SOC, the battery characteristics is analyzed in the different charging phase of the constant current and the constant voltage to obtain a high-precision estimation of the battery SOC in a discharging cycle. The experiment results show that an accurate estimation can be obtained and the estimation error is below 5%.