Distributed Power Sharing Strategy for Islanded Microgrids without Frequency and Voltage Deviations

This paper introduces a distributed power sharing strategy for the droop-controlled microgrids in which the power sharing errors and frequency/voltage deviations are completely eliminated based on the distributed cooperative control. The proposed strategy requires only a spare communication network in which the DG unit uses local and its neighbors' information to execute the control algorithm. In the proposed strategy, a virtual-impedance-regulator based on the consensus algorithm is developed to eliminate the power sharing errors in the islanded microgrid in spite of the load condition changes, and a modified droop controller based on the neighbors' power information is also introduced to cope with the frequency and voltage deviation issue. The proposed method does not use any information such as the feeder impedances, or the detailed microgrid configuration. The feasibility and effectiveness of the proposed method are also verified through digital simulation on an islanded microgrid system.