'Zero'-ripple EMI input filter concepts for application in a 1-U 500 kHz Si/SiC three-phase PWM rectifier

The basic principles of operation and the dimensioning of 'zero'-ripple filter concepts, as known for DC/DC boost converters, is discussed. Based on this a novel 'zero'-ripple input filter for a three-phase PWM rectifier system is proposed. The differential-mode characteristics of the filter and the influence of the filter on the selection of the unity gain bandwidth of the input current control is analyzed by simulations.