Topology Design and Performance Analysis of a MMC Based Solid-State Transformer

As a very promising power electronic equipment, the solid-state transformer (SST) provides favorable interfaces for distributed generation, energy storage, and various types of power loads. The research on the SST's structural topology is of significance. In this paper, a three-stage SST based on the modular multilevel converter (MMC) technology is established, and the related topology design and mathematical modeling method are presented with an elaboration of the control strategy. Finally, a simulation model of the designed SST is constructed in Simulink, and the SST connecting with 10 kV and 380 V power grids is done. From the simulation results, it is concluded that the SST can satisfactorily complete the predictive functions, thus verifying the feasibility of the proposed SST topology.