Study of alternative regimes to analyze two-stage PFC converter

Although two-Stage PFC converter has nonlinear nature of behavior, linear models are implemented through design process. Recently, low frequency instability has been detected in the two-stage PFC converter circuit. This instability can not be detected by the linear models. Therefore, in the current work, a new methodology of the two-stage PFC converter design is proposed. In such new methodology, nonlinear models of the two-stage are implemented depending of the time-varying averaged state-space equations and without using any assumptions to move it to linear model. Three different nonlinear models are developed and detailed comparison between them is provided. Experiment confirms the proposed models with a good agreement.