LAUSR

Abstract Droop control is commonly adopted method for sharing load current among parallel-operated DC–DC converters in DC microgrid. However, when different power ratings converters are parallel connected, it gives rise to circulating currents, which deteriorates current sharing. This paper proposes consensus-based distributed secondary control for voltage regulation and current sharing with different rating converters connected. A modified droop control is presented by employing average circulating current control strategy for mitigation of circulating currents. Moreover, to compensate the voltage deviation caused by droop control, a dynamic consensus-based average voltage control is designed. The proposed algorithms can achieve proper current sharing ratio among converters and also guarantee low voltage regulation. The effect of line resistance and communication delay is also considered and better performance is achieved. Simulation and experimental tests on two DC–DC parallel buck converters based microgrid systems show the effectiveness of the proposed method.