MMC-based solid-state transformer model including semiconductor losses

This paper presents the model of a solid-state transformer (SST) for distribution system studies with some advanced features. The model is based on a previous work in which a bidirectional SST with a MV-side modular multilevel converter (MMC) configuration was proposed. The new model incorporates the representation of semiconductor losses and some improvements in the control strategies of some SST stages. As the previous model, the new model has been implemented in Matlab/Simulink, and its behavior has been tested by carrying out several case studies under different operating conditions when the SST is connected to a radial distribution system. The paper also includes a discussion of the main model limitations and the future work.