Solid-state transformers (SSTs) typically use a front-end rectifier followed by a high frequency transformer-isolated DC-DC converter, and an inverter. These multiple stages increase component count and complexity. In contrast, this paper presents a novel topology for AC SSTs that solely uses isolated DC-DC converters and does not require additional rectification/ inversion stages. Simulation and experimental results from a three-phase AC prototype using series resonant DC-DC converter blocks are presented. The proposed SST can be used as a highly compact substitute for line-frequency transformers in space-constrained applications such as EV charging stations, wind turbine nacelles, and shipboard power distribution.
