Integrated magnetics for interleaved DC-DC boost converter for fuel cell powered vehicles

The conception, analysis and experimental demonstration of an integrated magnetics (IM) core structure for a 3-phase interleaved DC-DC boost converter for fuel cell powered vehicles are presented in this paper. The benefits of current interleaving in reducing inductor current switching ripple at low switching frequency and with low inductance are well known. The IM core structure enables volume and weight reduction of the magnetics over a discrete implementation while providing further ripple reduction of inductor currents and improved efficiency. The effect of magnetic coupling between the interleaving phases in the IM core is described. A novel composite IM core structure, which minimizes inductor current ripple, is introduced. Comparative analysis with a discrete implementation is presented. The advantages of matched duty cycles in reducing resistive power loss and simplifying the converter transfer functions are presented. The impact of parameter variation on the performance capabilities of the converter is described. Average and small signal models of the converter with the IM core are derived. Experimental results are presented to validate the operation and performance advantages of the proposed core structure.