针对微电网多储能单元因荷电状态、额定容量和线路阻抗差异导致部分储能单元过充过放,影响其使用寿命进而使微网稳定性调节能力变差的问题,提出一种基于变调节因子的多储能荷电状态(state of charge,SoC)均衡策略,通过反余切函数将下垂系数与SoC、额定容量关联,并引入虚拟压降补偿环节,实现多组储能单元间SoC均衡。在此基础上设计变调节因子,提高SoC均衡速度。仿真结果验证了所提策略能实现多组储能单元间SoC均衡,有效提升SoC均衡速度,并消除线路阻抗对SoC均衡及电流分配精度的影响。
英文摘要:
In view of the overcharge and over-discharge of individual energy storage units due to differences in the state of charge (SoC), rated capacity and line impedance of the microgrid multi-energy storage units, which will affect its service life and make the stability adjustment ability of the microgrid deteriorate, this paper proposes a multi-energy storage SoC dynamic balance strategy based on the variable regulating factor. The arccotangent function is used to associate the droop coefficient with SoC and rated capacity, and the virtual voltage drop compensation link is introduced to achieve the balance of multiple sets of energy storage SoC. On this basis, variable regulating factors are designed to speed up the SoC equilibrium speed between ESU. Simulation results verify the proposed control strategy can achieve SoC equilibrium between multiple sets of energy storage units, effectively improve the SoC equilibrium speed and eliminate the effects of line impedance on the SoC equilibrium and current distribution accuracy.