Research and Design of Three-Stage Power Electronic Transformer

With the development of smart grid and the advancement of renewable resource utilization technology, power electronic transformers have become an important energy conversion devices. Only AC ports are existed in traditional transformers. But power electronic transformers take into account both DC and AC ports, and have the advantage of facilitating the access of renewable energy compared with traditional AC systems. A three-stage power electronic transformer is proposed, which is composed of a three-phase PWM rectifier, a DAB DC-DC converter, and a three-phase inverter. And using the simulation platform based on MATLAB-SIMULINK to simulate and verify the proposed three-stage power electronic transformer. The verification results show that the power electronic transformer realizes the operation of unity-power factor on the grid side, the output voltage is controllable and it can be connected to the DC port.