Three-phase current-fed zero current switching phase-shift PWM DC-DC converter

A new topology of current-fed zero current switching (ZCS) three-phase DC-DC converter is proposed in this paper. The converter architecture is composed of a current-fed three-phase three-leg IGBT bridge, three single-phase high frequency transformers with star-connected primary, and three single-phase rectifier bridges with paralleled outputs. Primary IGBTs of the proposed modular phase converter are controlled with constant frequency phase-shift pulse width modulation technique. ZCS for all primary IGBTs is realized using transformer leakage inductance and small auxiliary AC capacitors connected in parallel to secondary side of single-phase transformers. The proposed converter is well-suited for current-fed high voltage alternative energy systems. Interval by interval analysis of steady state operation of the converter is discussed. Digital simulation and experimental test results are presented to investigate the converter design and operation.