A Solid State Transformer Model for Proper Integration to Distribution Networks

With the advancement in power electronic semiconductor switches such as silicon carbide and gallium nitride, it is possible to develop power electronics converters for high voltage, high power and high frequency applications. One such application is a power electronics based distribution solid-state transformer (SST). In this paper, a PSCAD based simulation model of the SST is proposed to have smooth integration to distribution network and smooth disconnection from distribution network. Smooth integration is required during start up and re-connection of the SST. Smooth disconnection of the SST is required during islanding of a part of distribution network. SST model must remain stable during both the processes. A distribution test system is used to evaluate the performance of the proposed SST model during start up and disconnection processes. Simulation results are provided to validate the proposed SST model.