Modeling and analysis of PWM converters with a new GSSA method

Due to the switching operation, the pulse-width modulation (PWM) converters are inherent time-variant systems with comprehensive dynamics. The generalized state-space averaging (GSSA) method is an approach to model them as time-invariant systems, defined by a set of differential equations and capable of representing circuit waveforms. This paper proposes a new generalized state-space averaging model to model the converters with variations in input voltage, which can give accurate ripple estimations and also helps for the control design without complicated calculation. The model can be treated as a basic modeling framework of some specific converters, such as the power factor correctors (PFC). As examples, the models of buck and boost circuits are analyzed and simulation results are presented.