Prototype of smart energy router for distribution DC grid

Smart energy router (SER), also called as power electronics transformer (PET) or solid state transformer (SST), will serve as a critical component in the next-generation electric power system. Taking advantage of modular multilevel converter (MMC) and input series output parallel (ISOP) topologies, new type of smart energy router has been developed. Presented architecture using two stages with AC/DC conversion in the medium-voltage (MV) side, and ISOP type DC/DC conversion in the low-voltage (LV) side, thus allows interaction with DC grid and local renewable sources, etc. Compared to existing topologies, proposed SER uses less power switches and high-frequency transformers. The details related to the 2-MVA SER prototype, including the electrical design of the circuits and control system is presented in this paper. Simulation and experimental results on this prototype with distribution DC grid show validity of this SER.