分布储能直流微电网中多储能荷电均衡控制策略

Charge balance control strategy for multiple energy storage in a distributed energy storage DC microgrid

在分布式储能孤岛直流微电网系统中,针对传统下垂控制策略无法实现荷电状态均衡、功率分配不精确和母线电压跌落的问题,提出了一种自适应下垂控制策略。首先将双曲正切函数与荷电状态相结合,利用双曲正切函数的特性,限制下垂系数的范围并且快速进行调整。然后通过调节补偿量,使下垂系数对应的电压相等,设计了功率分配的补偿策略。最后计算线缆阻抗,设计了二次母线电压补偿策略。Simulink仿真实验结果表明,所提控制策略可以实现荷电状态的均衡和功率的精确分配,并且使母线电压能够准确维持在额定值。

For a distributed energy storage island DC microgrid system,an adaptive sag control strategy is proposed to solve the problems whereby traditional sag control strategy cannot achieve the balance of charge state,the power distribution is not accurate and the bus voltage drops.First,by combining the hyperbolic tangent function with the charged state,the range of sag coefficient is limited and adjusted quickly through the characteristics of the hyperbolic tangent function.Then,by adjusting the compensation amount,the voltage corresponding to the sag coefficient is equal,and the compensation strategy of power distribution is designed.Finally,the cable impedance is calculated and a secondary bus voltage compensation strategy is designed.Simulink simulation results show that the proposed control strategy can achieve the balance of the charged state and the precise distribution of power,and the bus voltage can be maintained at the rated value accurately.This work is supported by Jilin Science and Technology Development Project(No.20220203066SF).