Actively clamped zero-current-switching quasi-resonant converters using IGBT's

Conventional zero-current-switching quasi-resonant converters (ZCS-QRC's) suffer from the disadvantages of high switch current stress and variable switching frequency. This paper proposes the use of a "current-clamping circuit" to overcome these disadvantages, By incorporating such a circuit into the family of ZCS-QRC's, a new family of actively clamped ZCS-QRC's using insulated gate bipolar transistors (IGBT's) is derived. These converters feature high land constant) switching frequency and zero-current turn-off (without increased current stress), which are particularly useful for high-power applications where minority-carrier semiconductor devices (such as IGBT's and bipolar junction transistors) are used as power switches, The design criteria, simulation, and experimental results are reported.