Adaptive droop control for high-performance operation in low-voltage DC microgrids

The most well-known means for the integration of various renewable energy resources is DC microgrids (DCMGs). Different control algorithms have been proposed to regulate the current and voltage of parallel energy sources. Droop control, a method for controlling DC microgrids, does not require a communication link. However, droop control has some constraints, such as not properly sharing the load among parallel converters and deteriorating voltage regulation. This paper proposes an adaptive droop controller to mitigate the problems of conventional droop control. The droop parameters are evaluated online and are adapted utilizing the primary current sharing loops to decrease the deviation in the load current sharing. In addition, the droop lines are shifted by the second loop to eliminate the bus voltage deviation of DCMGs. The proposed algorithm is assessed under various input voltages and load resistances. The simulation and experimental results illustrate the good performance of the introduced technique compared to classic control.