Comparison of four power electronic transformer topologies on unbalanced load correction capacity

This paper compares the unbalanced load correction capacity between four different PET topologies: the SPC modular topology, the CPC modular topology, the modular self-balancing topology and a proposed MAB based self-balancing topology. The theoretical analysis show that the SPC and CPC can only achieve unbalanced load compensation within a limited range and both of them require additional power rating of the semiconductor devices to achieve the compensation. The modular self-balancing topology and the MAB based self-balancing topology can achieve full-range unbalanced load compensation without requiring additional power rating of the semiconductor devices, but they require additional number of transformers and semiconductor devices. Simulation results verifies the unbalanced load compensation methods and their limitation of all these four topologies. This paper also compares the efficiency between the two self-balancing topologies. Theoretical results show that the MAB based topology has higher efficiency and it is verified by experiment results.