This paper presents a design method of a solid-state transformer (SST) for medium-voltage direct current (MVDC) Application. The traditional low frequency transformer requires a huge volume and weight to adopt for high-power and medium-voltage application. With growth of the power electronics technology, the solid-state switch based DC transformer became attractive candidate for DC distribution field. In this paper, the classification of SST topologies are introduced and a novel SST architecture is presented which is composed of modular converters. The various simulation results verify the effectiveness of the proposed SST design and its control strategy.
ACKNOWLEDGMENT This research was supported by a grant (18RTRP-B146008-01) from Railroad Technology Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.