A Three-Phase Interleaved DC–DC Converter With Active Clamp for Fuel Cells

In this paper, a three-phase interleaved dc-dc converter with an active clamp and three-phase pulsewidth modulation (PWM) method are proposed. The proposed converter has a three-phase interleaved boost converter, which consists of three input inductors, three active clamp switches, three-phase high frequency transformer, and diode rectifiers. Interleaved operation of a three-phase boost converter reduces overall ripple current, which is imposed into fuel cells and realizes smaller sized filter components, increasing effective operating frequency, and leading to higher power density. Each output current of the three-phase boost converter is combined by the three-phase transformer and flows in the continuous conduction mode, which leads to a reduction of rms current through switches and transformer windings. A peak efficiency of above 95% is achieved by a reduction in the conduction losses resulted by continuous current conduction and switching losses reduced by the action of active clamp branches, as well. The proposed converter and three-phase PWM strategy are analyzed, simulated, and implemented in hardware. Experimental results are presented to verify the feasibility of the proposed converter.