A Simple Large-Signal Nonlinear Modeling Approach for Fast Simulation of Zero-Current-Switch Quasi-Resonant Converters

A nonlinear modeling approach for zero-currentswitch (ZCS) quasi-resonant converters (QRC) is proposed which can be derived easily using simple analytical techniques. The converter model obtained is readily absorbed by MATLAB for analysis and design of both the openand closed-loop configurations in fast speed. Simulations have shown its accuracy, even for large-signal transient responses. Applications of this modeling approach to the three basic topologies of buck, boost, and buck–boost converters are given as illustrative examples. The condition for zero-current switching is identified from the model. The feasibility of applying this proposed modeling approach to the extended period QRC topologies is to be discussed. Simulation results for the three basic topologies are given to show the merits of the proposed modeling approach.