Design and development of Generation-I silicon based Solid State Transformer

The Solid State Transformer (SST) is one of the key elements proposed in the National Science Foundation (NSF) Generation-III Engineering Research Center (ERC) ¿Future Renewable Electric Energy Delivery and Management¿ (FREEDM) Systems Center. The SST is used to enable active management of distributed renewable energy resources, energy storage devices and loads. In this paper, the Generation-I SST single-phase 20 kVA, based on 6.5 kV Si-IGBT is proposed for interface with 12 kV distribution system voltage. The SST system design parameters, overall system efficiency, high frequency transformer design, dual active bridge converter, auxiliary power supply and gate drives are investigated. Design considerations and experimental results of the prototype SST are reported.