Low-frequency modeling of three-phase, four-core, strip-wound transformers in high-power DC-DC converters

In this paper, a low-frequency model for a three-phase, four-core transformer geometry, which is commonly applied in amorphous core distribution transformer technology, is presented along with an experimental verification and additional simulation results. The model is intended for transformers operating as a part of three-phase dual active bridge converters in DC-based utility systems. Since the designed transformer has an unsymmetrical core configuration, the values of leakage and magnetizing inductances differ for each phase. The simulation results of asymmetries which influence the electrical and magnetic parameters of the transformer such as voltages and the core peak fluxes are presented. Simulative investigations of additional asymmetries are presented as well.