Parallel operation of converter interfaced multiple microgrids

This paper proposes methods to control utility connected multiple microgrids. Microgrids with renewable energy sources and autonomous operations do not have high reliability while the smart grid vision demands a highly reliable and efficient grid. Thus the connections of the microgrids to the main grid have to be smart itself. A back to back (B2B) converter connection can provide a reliable interface and also can provide isolation between utility and microgrids. However, with multiple microgrids connected through B2B converter connections can lead to system instability. In this paper, a method to coordinate the B2B connections without losing the possibility of autonomous operation of the microgrids is proposed. The system stability is improved first with a decentralized control of the B2B converters. Then with smart grid scenarios in mind, an application of communication is proposed and simulated. The proposed control strategy demonstrates stable system operation with multiple microgrids connected to utility through B2B converters. The mathematical model of the system with analysis and closed loop simulation of power network and communication network are presented to validate the claim.