Concepts, Configurations, and Challenges of Solid-State Transformer: A Review

Rapid and sudden increase in the use of small Distributed Renewable Energy Resources (DRER) and Distributed Energy Storage (DES), reduced compact dynamic electrical power consumer-like electrical vehicle loads, the requirement of a bidirectional power flow communication network to exchange critical information, other ancillary services, etc. has to be envisaged and fulfilled by a future smart distribution grid system. A solid-State Transformer (SST) has more potential solutions to provide stable and efficient distribution system operation to overcome the above problem. From various designs of converter control schemes, the solid-state transformer concept has been evaluated and summarized. The benefits and downsides of converters in the AC/DC, DC/DC, and DC/AC stages are studied for the best configuration. The High-Frequency Transformer (HFT) is a main part of SST. The design and optimization of an HFT are approached to minimize the weight and size of the SST. Researchers also face several challenges in the prototype design and implementation of SST before operating effectively in the distribution system which is presented. Some expected solutions and future recommendations for the establishment of the solid-state transformer for future smart electrical distribution systems are discussed.