Magnetically integrated isolated bidirectional three-port DC-DC converter

This paper presents a magnetically integrated isolated bidirectional three-port DC-DC converter (TPC) that includes an integrated dual active bridge converter (DAB) and non-isolated bidirectional DC-DC converter (NBC), each of which can be independently controlled. The proposed TPC simultaneously uses large, small, and magnetizing inductances, of which the small and magnetizing inductances are used for the DAB function, while the large inductance is used for the TPC function. The proposed magnetic component can function as any of the three inductances in the TPC. We constructed a 750 W, 175 kHz prototype of the proposed TPC along with an example of a conventional TPC and measured their respective efficiencies. The results show the efficiencies of the integrated TPC were all above 90% across the entire range of output power and were nearly equal to those of the conventional device. However, compared to the conventional type, the magnetic components in the proposed converter were 10% smaller, and the overall size of the converter was 33% smaller.