A New Five Level Dual Active Bridge DC-DC Converter for Solid State Transformer

Abstract

Solid State Transformer (SST) is the main focus of research in recent years. Bidirectional Isolated Dual Active Bridge is an important component in SST. When conventional control scheme such as Single Phase Shift (SPS) is used it reduces the system efficiency due to circulating power and has high dv/dt across switches. It has only one degree of freedom which confine its ability to regulate power flow. In this paper, 5-level Dual Active Bridge is proposed with three degree of freedom which improves its ability to regulate power flow. Moreover due to increase in voltage levels, dv/dt across switches reduces significantly and it also reduces the circulating power which improved the efficiency of system. Performance of the proposed topology has been varified in MATLAB.