A Two-Stage Improved Droop Control Method for Economic Operation of Islanded DC Microgrids

The traditional droop control method applied to DC microgrids causes undesirable steady voltage deviations and it does not consider the economic operation. To overcome these drawbacks, this paper proposes a two-stage improved droop control method for the economic operation of islanded DC microgrids in the light of equal incremental cost principle. A time-delay feedforward path of cost incremental value is deployed in the droop control strategy, which can eliminate the steady voltage deviation while ensuring efficient power sharing. In addition, a plug-and-play strategy based on the proposed control is presented to enhance the system reliability. Simulation results verify the effectiveness of the proposed control method.