Abstract:Aiming at the problems of unbalanced state of charge, poor current distribution accuracy and DC bus voltage deviation in DC microgrid energy storage system, this paper proposes an accelerated SOC balance control strategy for DC microgrid distributed energy storage to improve current sharing accuracy. Firstly, the variable acceleration convergence factor based on exponential function is introduced into the adaptive droop control based on hyperbolic tangent function, which can accelerate the SOC balance between energy storage while limiting the droop coefficient range. In order to reduce the influence of line impedance on current distribution, the virtual voltage equalization control is carried out for each converter, and the compensation amount is adjusted adaptively to reduce the influence of line impedance on SOC balancing effect. Finally, the bus voltage is compensated by secondary voltage to solve the problem of bus voltage deviation caused by droop inertia. In addition, the stability analysis based on the