An improved zero voltage transition PWM boost converter with an active snubber cell

Abstract

This study presents an improved zero voltage switching (ZVS) boost converter with an active snubber cell providing soft switched operation for all semiconductors. The active snubber cell reduces the reverse recovery loss of the boost diode and also provides the zero voltage transition (ZVT) Turn-on and ZVS Turn-off for the boost switch. The zero current switching (ZCS) Turn-on and ZVS Turn-off for the snubber switch is also achieved. All diodes in the converter can be operated with soft switching (SS). In the snubber cell, SS energy can be transfered effectively to the output by the use of a snubber inductor and a capacitor. This energy transfer allows the use of additional parallel connected capacitor to the boost switch to provide ZVS turning off. There is no additional voltage and current stress on the boost switch and boost diode. The voltage stress of the snubber switch is also limited by the output voltage and the current stress of the snubber switch is reduced by the energy transfer to the output. SS operating of the semiconductors is maintained at very wide load ranges. The operation of the proposed converter is presented with a detailed steady state analysis. The predicted theoretical analysis is validated by a prototype with 500W output power and 100kHz operating frequency. The measured maximum efficiency values are obtained as approximately 97% and 85.4% at full load and 10% load conditions, respectively. © 2016 World Scientific Publishing Company.