Abstract:
To improve the inertia support of DC microgrid control containing distributed energy storage system, a control strategy centered on VDCM is designed. Firstly, it is analyzed that the VDCM itself has sagging characteristics without integration in the voltage loop, and then for the problem of
SOC equalization control, this paper proposes a control strategy with an adaptive VDCM armature resistance coefficient, which realizes that the coefficient is adaptively adjusted under the action of the
SOC deviation index, and achieves the goal of
SOC equalization control and power equalization. To realize the plug-and-play nature of the distributed energy storage unit while realizing the voltage loop and
SOC equalization control needs, a dynamic consistency algorithm is introduced to iterate out the average value of the
SOC and energy storage output voltage. The control strategy proposed in this paper globally simplifies the conventional control strategy while introducing additional inertia and damping to the system to enhance the robustness of load switching and photovoltaic uncertainty. Simulation tests demonstrate the effectiveness of the method in coping with the problems of line impedance, power distribution,
SOC equalization, and bus voltage droop.