微电网中多储能电池组电压-SOC分段均衡控制策略研究

Study on Voltage-SOC Segmented Equalizing Control Strategy for Multiple Stacks ofEnergy Storage Batteries in Microgrids

针对直流微电网中多储能电池组在充放电末端以荷电状态(SOC)为均衡变量时电压误差大的问题,提出了一种多储能电池组电压-SOC分段均衡控制策略。根据开路电压与SOC的关系变化曲线进行分段,充分利用电压均衡计算量少、SOC均衡效果好的优点,在充放电始末端以电压作为均衡变量,在电压平台期以SOC作为均衡变量,采用下垂控制实现多电池组间的均衡控制。为验证均衡策略的有效性,在MATLAB/Simulink中搭建仿真模型,仿真结果表明电池组充放电完成后能同时保持电压和SOC良好的均衡效果,有效提高多电池组间的一致性。

Aiming at the problem of large voltage error of multiple stacks of energy storage batteries in a DC microgrid when the state of charge(SOC)is used as the equalizing variable at charging and discharging ends,a segmented voltage SOC equalizing control strategy is proposed.Segmentation is performed based on the relationship between open circuit voltage and SOC,achieving full potential of the advantages including less voltage balancing calculation and good SOC balancing effect.Voltage is used as the balancing variable at beginning and end of charging and discharging,and SOC is used as the balancing variable at voltage platform stage.Sag control is used to achieve equalizing control between multiple stacks of batteries.To verify the effectiveness of the proposed strategy,a simulation model was built in MATLAB/Simulink.The simulation results showed that the battery stacks can maintain good voltage and SOC equalization effects after charging and discharging,effectively improving the consistency among multiple stacks.