Bidirectional Boost Converter based Solid State Transformer for AC/DC Micro-Grid Application

In the existing electric power distribution network, a large number of AC/DC Micro-Grids are playing their role independently to provide the desired power supply to all the consumers. However, under short time outages, natural disasters, or sudden changes in system parameters, this AC/DC Micro-grid needs to interface with the existing power grid or with each other or to be disconnected from each other to help out for seamless power supply to all the consumers in the distribution network. Conventional, low-frequency transformer used in such network, is having so many drawbacks such as low power density, poor voltage regulation, and no control over power flow with poor power quality. Sold State Transformer (SST) is a viable solution for such applications. This paper presents a structure of SST for AC/DC Micro-Grid converter (MGC). A bidirectional boost converter and a stacked half -bridge inverter are integrated with the AC/DC Micro-Grid converter. The designed 6 KW Micro-Grid Converter has a bidirectional power flow controllability with a soft switching feature to improve the overall efficiency of the converter. The designed AC/DC MGC is simulated in PSIM/Simulink co-environment to verify it's performance indices under different operating conditions.