State-plane approach to the small signal model of parallel resonant converters

A small-signal analysis of a conventional parallel resonant converter operating in the continuous conduction mode is given. This analysis is based on the state-plane approach that has been successfully used to obtain the steady-state response for resonant converters. Applying perturbation directly to the steady-state trajectory, a discrete small-signal model for the converter can be derived in terms of the input voltage, switching frequency, and the converter state variables. Frequency responses of two transfer functions are obtained: input-to-output and control-to-output transfer functions. Computer simulation and experimental results are presented to verify the theoretical work