一种基于能量建模的锂离子电池电量估算方法

A Method to Estimate the Capacity of the Lithium-ion Battery Based on Energy Model

锂离子电池放电起动瞬间电压陡降以及放电停止后电压回升使开路电压和实时电压关系难以确定,进而导致常规方法无法准确估算荷电状态(State of Charge,SOC)。从能量角度提出一种应用于电池放电过程中估算SOC的新方法。首先构造带有非线性受控源的双电源模型,然后根据电池电量特性进行模型参数辨识。通过对锂离子电池进行恒流、变流和模拟工况放电过程中的SOC预测,对比模型预测和实测SOC可看出,该方法能够准确模拟电池电量特性,精准估算电池SOC。

The Lithium-ion battery has a steep drop of the real-time voltage at the start of the discharge and a rise of the real-time voltage at end of the discharge, which makes it difficult to determining the relationship between the open circuit voltage and the real-time voltage and also causes difficulties for estimating the state of charge （SOC） accurately with conventional methods. In response to this, a new method based on energy model for estimating the SOC of the lithium-ion battery during the discharge is put forward. Firstly, the dual-source model with nonlinear controlled sources is proposed, and then the parameters of this model are identified according to the capacity characteristics of the battery. The SOC is forecasted under the condition of the constant current discharge, the variable current discharge, and the simulated working condition. The comparison of the predicted and the measured SOC proves that the method can accurately simulate the capacity characteristics of the battery and estimate its SOC.