An Integrated Magnetic Structure for Bi-Directional Two-Channel Interleaved Boost Converter with Coupled Inductor

The channel current in an interleaved boost converter consists of circulating Differential Mode (DM) current and Common Mode (CM) boost current. Inverse-coupling between inductors, compared with the uncoupled case, offers reduced channel current ripple. However, its leakage inductance, that serves as boost inductor, is difficult to control. Hence, a cascade of two perfectly coupled inductors, inverse (DM inductance) and direct (CM inductance), is preferred. The DM and CM currents and their ripples depend on these inductances. Nonetheless, this approach results in increased size of magnetics. In this paper, an integrated inductor, based on gapped EE-core is proposed, that combines both CM and DM inductances in a single core. The CM and DM inductances are independent and can be controlled separately by their winding turns. A reluctance model is derived, and a design procedure is developed where core parameters are expressed in terms of converter parameters. Finally, the proposed concept is validated through a 330W, 100 V to 168 V prototype.