Decentralized current sharing in dc microgrids considering normal and disturbed operation modes

Abstract

The accurate ratio-based current sharing, which is one of the desired features of the droop controlled dc microgrid, might be affected by the system impedance. Several strategies have been presented in the literature to achieve precise current sharing. This paper proposes a new controller reconfiguration algorithm that is capable to achieve enhanced operation during normal conditions and after system disturbances. For this purpose, the proposed algorithm allows the converter to follow the set-points determined by a higher-level controller when there is no disturbance in the system. After a system disturbance, when the necessity for the current sharing arises, the proposed controller enables accurate ratio based current mismatch sharing between the droop controlled converters. The time-domain simulation conducted in Matlab/ Simulink environment demonstrates the effectiveness of the proposed approach.