Unified approach to modeling, synthesizing, and analyzing quasi-resonant converters

This paper presents a general method of modeling, synthesizing, and analyzing quasi-resonant converters (QRC's), including actively clamped QRC's. First, the concept of the pulse-width modulation (PWM) switch model is generalized to encompass all PWM (nonisolated) converters. Then, by adding inductor-capacitor (LC) elements and auxiliary switches into the PWM switch, QRC families are synthesized. DC and small-signal analyses can be carried out based on these switch models. Furthermore, the duality relationship between zero-voltage-switching (ZVS) and zero-current-switching (ZCS) QRC's is established systematically and rigorously.