Virtual inertia control strategy at energy-storage terminal in DC microgrid

Due to the low inertia of DC microgrid system, the DC bus voltage oscillation is easily resulted by the large power gap of the system. Therefore, the virtual inertia control strategy at the energy-storage terminal in DC microgrid is proposed. The strategy sets the droop coefficient at the battery terminal as a function, which takes the voltage variation rate as the variable; When the DC microgrid system is disturbed, the battery provides additional inertia power, equivalents to increasing the capacitance on the DC side. In addition, to meet the requirement for response speed of the DC microgrid system under different voltage variation rates, this paper proposed a virtual inertia control strategy with droop coefficient a piecewise function. Finally, to verify validity of the proposed strategy, simulations based on Matlab/simulink are conducted and the results verify the effectiveness of the strategy.