Trapezoid current modulated DCM AC/DC DAB converter for two-stage solid state transformer

Solid state transformer topologies (SST) have gained great attention because of having features such as reactive power compensation, output voltage regulation and smart grid operation etc. Among SST topologies, three-stage topologies have been mainly focused because there are many appropriate topologies for each conversion stages. However, conventional three-stage topologies may bring complex closed loop control methodologies, high value inductances and capacitances and hard switching losses. In this study, we proposed trapezoid current modulated DCM AC/DC DAB converter for two-stage SST. The proposed converter achieves soft switching; hence it can have high efficiency. Moreover, it can be operated by open loop control with eliminating high-frequency current sensors. In this paper, the analysis of the proposed converter is presented and theoretical analyses are validated by simulations.