A new family of zero-current-switching PWM converters and a novel HPF-ZCS-PWM boost rectifier

This work presents a new family of DC to DC converters based on a new zero-current-switching (ZCS) pulse-width-modulated (PWM) soft-commutation cell. Two transistors (main and auxiliary switches), two diodes, two small resonant inductors and one resonant capacitor compose this commutation cell, appropriated to operate with insulated-gate bipolar transistors (IGBTs) as the power switches. This new ZCS-PWM cell provides a zero-voltage (ZV) turn-on to the diodes, a zero-current (ZC) turn-on and a zero-current-zero-voltage (ZCZV) turn-off to the transistors. The new family of converters, originated from the proposed ZCS-PWM cell, offers conditions to obtain isolated converters, as example: derived buck-boost, Sepic and Zeta converters. An application of the new commutation cell in a new ZCS-PWM boost rectifier is developed, obtaining a structure with power factor near unity, high efficiency at wide load range and low total harmonic distortion (THD) in the input current. The principle of operation, the theoretical analysis and the design procedure are presented. A design example is developed and experimental results to the new high-power-factor (HPF) ZCS-PWM boost rectifier are presented to verify the theoretical analysis.