Solid-state transformers using silicon carbide-based modular building blocks

Solid-state transformers (SSTs) that process power through power electronics and high frequency transformers are an interesting alternative to line-frequency transformers. In addition to weight and possibly size reduction, solid-state transformers can provide enhanced controllability. Emerging silicon carbide (SiC) power devices that can block higher voltages, conduct current more efficiently, and switch faster than silicon power devices are providing a new impetus to the development of SSTs. This paper discusses several versions of MVA-scale SSTs designed for medium voltage AC or DC applications using modular power electronic building blocks. The building blocks are based on 1.7kV to 10 kV SiC MOSFETs and 20 kHz–200 kHz transformers. Test results from prototypes are presented.