Design and Evaluation of A Magnetically-loosely-coupled Inductor for A Four-phase Interleaved Boost Chopper

An interleaved boost chopper is used between the battery module and the traction inverter in electric vehicles including fuel cell vehicles and hybrid electric vehicles as one of the applications. However, this circuit requires the increased number of components such as inductors and switching devices in comparison with a general chopper. This paper proposes a new type of magnetically-loosely-coupled inductor for a four-phase interleaved boost chopper and compares the characteristics between the proposed and non-coupled inductors used in the chopper. As a result in the experiment, it is shown that the magnitude of the current ripple in the proposed inductor is 74~83 % smaller than that of the non-coupled inductor. In addition, the power conversion efficiency of the chopper using the proposed inductor is higher than that using the non-coupled inductor in a case where the inductor current flows continuously.