A three-phase integrated power electronic transformer with the capability of DC fault clearance

This paper presents a three-phase integrated power electronic transformer (PET) topology with the capability of DC fault clearance based on the investigation of PET topology. The proposed PET has three ports of high-voltage AC, high-voltage DC and low-voltage DC, which can achieve the flexible access of distributed energy resources. The power unit of the PET adopts a three-phase integrated topology, and the single-phase fluctuating power in the DC-link capacitor is reduced by a 4-port DC/DC converter, thereby reducing the capacitance of the DC-link capacitor; Meanwhile, the power unit uses the clamp double sub-module(CDSM) to allow for self-clearing of the short-circuit fault on the high-voltage DC side. Finally, this paper verifies the proposed PET through an EMT simulation and experimental prototype.