Hybrid Energy Storage Coordinated Control of DC Microgrid Based on Virtual Inertia

As a small inertia system, DC microgrid has poor anti-interference ability. When disturbance occurs, the bus voltage is difficult to maintain stability. In order to improve this shortcoming, a coordinated control strategy for hybrid energy storage of DC microgrid based on virtual inertia is proposed. Based on the complementary advantages of hybrid energy storage, this strategy introduces the virtual inertia control at the converter side of the battery, connecting the DC bus voltage with the control coefficient in the converter, so that it can provide the corresponding inertia for the system according to the voltage fluctuation, so as to improve the weak grid characteristics of the DC microgrid. The simulation model of DC microgrid system is established based on Matlab. The simulation results verify that the proposed control strategy can effectively suppress voltage fluctuation when the system power is unbalanced, which can achieving the purpose of improving the quality of the DC bus voltage.