Design of a bi-directional DC-DC converter for Solid-State Transformer(SST) application by exploiting the shoot through mode

Abstract

This paper concerns the design of a Solid-State Transformer (SST) based grid integrated battery charger with an isolated bi-directional dc-dc converter to maintain the overall system competitiveness. The proposed full bridge DC-DC converter exploits the shoot through mode in the V2G mode for the boosting purpose, which is the uniqueness of the proposed topology. The inclusion of SST in the design can exhibit substantially compact size and other potential functions such as reactive power flow control, bi-directional power flow etc. The design of the high frequency transformer along with the electrical equivalent circuit obtained from FEA analysis is presented, which is one of the key contributions of this paper. As a proof of concept, simulation results obtained from Matlab-Simulink tools are presented. In summary, design considerations in building the SST based DC-fast charger in a 1-kW power level are presented which can be scaled up to the desired power level according to the requirements.