Analysis and selection of switch for double modes inverter in micro-grid system

Double modes inverters, as the interface devices between the microgrid system and public grid, plays an important role in the distributed generation system. In order to realize the connection and disconnection between double modes inverter and public grid, an intelligent switch is necessary. The switch is used to detect the status of grid and inverter, adjust the frequency, amplitude and phase of inverter, realize seamless transition. Three types of switch were introduced in this project, CB-based, SSR-based, and IGBT-based switch. The configuration, performance and application of these switches are analyzed in this paper. The state machine which was used to control the transitions operation between grid-connected mode and stand-alone mode also was illustrated.