A Bidirectional Droop Control Strategy for the Hybrid Microgrid with AC/DC Distributed Generation Integration

In hybrid microgrid with AC/DC distributed generation integration, the bidirectional converters take charge of the power balance among AC subgrid and DC subgrid. For the droop-controlled distributed generations both in the two subgrids, the bidirectional converters should manage these two different kinds of power droop characteristic. In this paper, the two kinds droop control are described as the droop characteristic of AC bus and DC bus of the bidirectional AC/DC converters. Then a novel active power control strategy for the converters based on the bidirectional droop characteristic is proposed to realize the power balance and independent sharing. Along with the droop control in both AC and DC subgrid, the power balance and independent sharing in the hybrid microgrid can be realized and the plug-and-play feature of the distributed generations is ensured. Small signal modeling and analysis of the bidirectional converter are conducted to evaluate the characteristics of the proposed control with different parameters. Simulation results based on PSCAD/EMTDC show the validity and efficiency of the proposed control strategy.