Interleaved association of ZVS-PWM three-phase current-fed push-pull DC-DC converters with series output connection

This paper proposes an association of two ZVS-PWM three-phase current-fed push-pull DC-DC converters. The ZVS-PWM three-phase current fed push-pull DC-DC converter is already known in literature and can be used to reduce the volume, weight and consequently the cost in many applications when compared to single phase topologies. The proposed association allows the division of the input current between the two converters and the sum of the individual output voltages to obtain the total output voltage. The proposed association presents benefits when is compared with the individual converter in applications with low input voltage and high input current. The main benefits of this association in relation to the individual converter for the same power are: reduction of the RMS current through the switches - decreasing the losses, reduction the input current ripple and half the voltage stress across diodes and capacitors of the output rectifier stage. The analysis of the proposed association, a design example, and the simulation results for an output power of 1 kW with an input voltage of 50 V, an output voltage of 400 V and a switching frequency of 40 kHz are presented to validate the analysis.