Transient Analysis of Quasi-Resonant Converter Based on Equivalent Small Parameter Method Considering Different Time Scale

This paper proposes a modeling and transient analysis method for quasi-resonant converter (QRC) based on the equivalent small parameter method (ESPM), with different time scale features being considered. Due to the existence of resonant and filtered state variables with different time constants, time scale factors should be taken into account to accurately describe the transient characteristics of QRC. First in the process of modeling, the circuit was divided into several networks according to different time constant. Then the unified nonlinear mathematical model of networks with different scales can be achieved. Next use the improved method to study the above model and obtain analytic solutions. Finally, the simulation results are presented to verify the performance of the applied method for modeling and analysis of the circuit.