Discrete Time Modeling of Variable Frequency Pulse Width Modulation Controlled Single Stage Three-Level Resonant AC/DC Converters

In this paper a generalized discrete time modeling approach, suitable for the prediction of both steady state and transient performance of different single stage three level resonant AC/DC converters under VFPWM control, is proposed. This method is based on a quantized combination of averaging and multiple frequency modeling. Effects of nonlinearities and parasitic effects will also be described by this model. The proposed model is effective for digital controller design and implementation. The proposed model is verified through a 2.3 kW, 48 V three-level, single stage LCC converter with input voltage varying from 90-265 Vrms.