Design and Validation of A 2MW 10KV Medium-voltage Solid State Transformer

The solid-state transformer (SST), a power electronics-based voltage transformation equipment, has caught much attention in the last decade. This paper presents the design, development, and validation of a silicon carbide (SiC) based 2MW SST with 10kVac input and 800Vdc output. The SST system employs an input serial and output parallel (ISOP) topology, with cascaded H-bridges (CHB) used as active front end (AFE), and dual active bridges (DAB) used as isolated dc-to-dc converters. A distributed control architecture is applied with fiberoptics based star-type communication network. The SST passes insulation test of 42kV withstand voltage and 75kV lightning impulse. The power density of the developed SST is 223kW/m². Two full SST prototypes were built and validated to full voltage and full power in laboratory, with peak efficiency measured at 98.3%.