Decoupled load sharing of multiple distributed generators in DC microgrids

DC Microgrids have been promoted due to their advantages of higher efficiency, higher reliability, and easier connection. The traditional droop based control can obtain fair performance of voltage regulation and load sharing when the dynamics of distributed generators are out of consideration. However, in practical cases, the distributed generators have different dynamics. This makes the DC Microgrid to be a multi-time scale system. The corresponding modeling and load sharing control need to be re-examined. In this paper, a multi-time scale model is introduced by adding virtual inductances. Then the interaction of load sharing control loops among different distributed generators is investigated by relative gain array method. A Dynamic Decoupling Control based on Adaptive Disturbance Injection Control is proposed to solve the coupling problem. Simulations in Matlab/Simulink and experimental tests are conducted to verify the effectiveness of the proposed method in multi-time scale DC Microgrids.