An Effective DC Microgrid Operation Using a Line Impedance Regulator

Droop control is a widely used technique for load sharing in DC microgrids (MGs). However, it has its limitations due to the MG voltage deviating from its rated level and, more importantly, it suffers from possible poor current sharing accuracy. Voltage drops across coupling line impedances is the main factor that causes these limitations, which is further deteriorated by the virtual impedance introduced by droop action. This paper studies the possibility of canceling the effect of this coupling line voltage drop to enhance the performance of droop control. In that regard, a line impedance regulator (LIR) has been developed to compensate for the coupling line voltage drops. The effectiveness of the proposed method is verified through simulations and experiments, performed on MATLAB/Simulink, and DC MG test bench, respectively.