PERFORMANCE IMPROVEMENT OF SOFT-SWITCHED PWM RECTIFIERS WITH INDUCTIVE LOAD

A new soft-switched ac/dc pulse width modulation (PWM) converter struc ture is presented, It is useful for current-fed inverters and PWM rect ifiers, Typical applications are magnet power supplies, high-power ac motor drives, and active power filters with magnetic energy storage, S oft switching is provided at the expense of a limited increase of the circuit complexity as compared to usual hard-switching solutions, A di scussion of the soft commutation process is presented, By a proper swi tching sequence, overvoltages across the converter switches can fully be eliminated, Moreover, light-load operation can be achieved, Both ty pical limitations of soft-switched current-fed topologies are therefor e overcome. Simulation and experimental results demonstrate the actual converter capabilities.