A review on solid-state transformer: A breakthrough technology for future smart distribution grids

•First, we summarize the concept of SST with design principles, including converters, switches, and other components.•In addition, the applications of SST for power distribution systems, traction locomotives, and electric vehicles are discussed.•The various topologies of SST are also discussed and reported in tabular forms.•Further, SST outcrop suchlike reliability, resiliency, and stability using SST are presented. The modern power systems have now prompted the practice of power electronics-based converters for power conversion purposes, which has emerged a solid-state device named as solid-state transformer (SST). It provides the isolation between low/medium-voltage ports with a high-frequency transformer (HFT), and in addition, it facilitates controlling the active and reactive power automatically through power converters. With this objective, the SST is projected as an essential device for smart/microgrids, particularly in multi-microgrid systems, to enhance modern distribution systems' resiliency. This study explores how it is beneficial to the distribution systems in regards to the reduction of size, controllability, reliability, resiliency, and end-use applications. Moreover, the different component types and broad applications have also been discussed pertaining to their characteristics. Lastly, the conclusion gives a brief summary, and the possible direction of future research is presented, which will be useful for researchers and engineers working in future microgrids and smart grids.This review will guide to select appropriate components to develop an SST for a particular application.