基于PID控制的SOC估算方法研究

SOC Estimation Method Research Based on PID Control

常用安时积分法在对电动车载锂电池荷电状态(state-of-charge,SOC)估算过程中存在初始、累积误差问题,而卡尔曼等闭环智能算法,因算法复杂度问题在实际电池管理系统(Battery Management System, BMS)中较难执行且系统响应速度相对较慢。针对上述问题,利用PID闭环反馈对被控量进行校正的原理,在锂电池动态Thevenin模型的基础上实现对锂电池容量进行补偿的同时,通过端电压误差调节器生成SOC的补偿量,实现对安时积分SOC估计结果的修正和补偿。仿真和实验结果表明,基于闭环补偿原理的SOC估算方法具有较高的估算精度和较好的实时性。

The general method of the ampere-hour integral has the initial and accumulative error in estimating the state-of-charge (SOC) of lithium battery in the electric vehicle. However, Kalman and other intelligent closed-loop algorithms are more difficult to execute and response in the actual Battery Management System (BMS) is relatively slow, because of the complexity of the algorithm. In view of the above problems, the principle of closed-loop feedback used in correcting the controlled quantity is used to compensate the capacity of lithium battery on the basis of the dynamic Thevenin model of lithium battery, and the compensation of SOC that is generated by the terminal voltage error regulator can realize the correction and compensation of estimation results in the SOC of ampere-hour integral. Simulation and experimental results show that the SOC estimation method based on the closed-loop compensation principle has higher estimation precision and better real time performance.