A scheme of connecting microgird to AC grid via flexible power electronics interface

Based on the synthetic control of microgrid, a flexible power electronics interface is developed in this paper. Considering distributed generation types and storage devices, different control strategies are adopted in controller design for different distributed generation units. The interface comprises a couple of back-to-back VSC converters, and exports variable active power and reactive power in order to maintain the power balance inside the microgrid. Apparently, the interface separates the microgird from the AC grid, prevent harmonic component transmitting from one side to the other side and control the active power precisely flowing between microgrid and main grid. Besides, it´s also in charge of reactive power compensation and keeping the microgrid voltage stable. Simulation results can approve its superiority and validity comparing with direct connection.