High power DC/DC converter using extreme close-coupled inductors aimed for electric vehicles

The DC-DC converter using coupled inductors is known as one of the topologies that achieve higher power density. This paper focused on this topology especially using extreme close-coupled inductors (ECCI). Following the elucidation of design guidelines for the coupled inductor theoretically, the superiority of the interleaved converter using ECCI in terms of reducing the size and losses in the magnetic components is demonstrated clearly through comparison with an interleaved converter using a set of looser-coupled inductors and a conventional single inductor converter. The effect of increasing a magnetic coupling factor of a set of coupled inductors from 0.980 to 0.999 is investigated by comparing it with other inductors of interleaved converters. The high power prototype converter with the coupling factor of 0.999 provides excellent performance with a time rating power density of 25.6 kW/liter.