Analysis and design of extended soft-switching current-fed three-phase dc/dc converter with simple modulation technique and magnetizing inductance effect

Three-phase current-fed dc/dc converter with active-clamp is analyzed with magnetizing inductance effect employing a novel simple modulation technique. Magnetizing current extends soft-switching range of power semiconductor devices. The topology is suitable for high current applications. Steady-state analysis and design of converter has been presented. Active-clamp circuit limits the bridge switch turn-off voltage overshoot and enables higher energy storage in the transformer´s phase leakage inductances to achieve zero-voltage-switching (ZVS) turn-on of the semiconductor devices. Active-clamp switch also maintains ZVS over wide operating range of source voltage and output power. Zero-current switching (ZCS) of rectifier diodes is achieved. Simulation and experimental results are demonstrated to verify the steady-state operation, analysis, and design as well as to test the converter performance.