An Improved Droop Control Method for Accurate Power Sharing and Bus Voltage Restoration in DC Microgrid

Generally, the droop control is used to realize the sharing of load power in DC microgrid. Considering the influence of line resistance on sharing accuracy and the problem of the drop of the DC bus voltage, in this paper, an accurate power sharing method and a voltage restoration method based on information sharing are proposed. By defining the "unit current" of the distributed generators (DGs), the reference voltage compensation of each DG is deduced, so that the accurate power sharing is achieved. Based on this, a feasible method is proposed to transform the above voltage compensation into the droop coefficient compensation. In addition, a distributed DC bus voltage restoration method is proposed, which does not need to add centralized PI controller. Finally, the simulation results of MATLAB/Simulink verify the effectiveness of the proposed control method.