Benefit analysis of using multi-port and multi-function power electronic transformer connecting hybrid AC/DC power grids

This study proposes a generalised configuration of the multi-port and multi-function power electronic transformer (MPMF-PET) based mixed AC/DC power grids, and the equivalent circuit and mathematical model of the MPMF-PET are established. To illustrate the benefits of using MPMF-PET to improve the integration and power control ability of a distributed energy resource in an existing distribution network, an iterating evaluation algorithm is proposed for system power flow calculations. Case studies are carried out on a real distribution system modified with MPMF-PET. Results show that the performance of the hybrid AC/DC distribution system is increased by MPMF-PET through proper control and optimal operation, which realised the renewable energy in the AC system to power the DC system and increased the renewable energy acceptance.