A ZVS-PWM Three-Phase Current-Fed Push-Pull DC-DC Converter

In this paper, a ZVS-PWM three-phase current fed push–pull dc–dc converter with reduced harmonics is proposed. When compared to single-phase topologies, the three-phase dc–dc conversion increases the power density, uses the magnetic core of the transformer more efficiently, reduces the stress on switches, and requires smaller filters since the frequency for its design is higher. The proposed converter employs an active clamping technique by connecting the primary side of the transformer to a multi level inverter and a clamping capacitor and secondary side with three-phase full wave rectifier. This circuit allows the energy from the leakage inductances to be reused, increasing the efficiency of the converter. If appropriate parameters are chosen, soft-commutation of the switches (ZVS) can also be achieved. The softcommutation improves the efficiency even further, allows higher switching frequencies is to be used, and reduces the electromagnetic interference significantly. Applications such as fuel cell systems, transportation, and uninterruptable power supplies are some examples that can benefit from the advantages presented by this converter.