Modeling of a single-switch quadratic buck converter

Ready-to-use nonlinear and linear averaged models for a single-switch quadratic buck converter are given. The nonlinear model is obtained from an averaged equivalent circuit model of the converter using the PWM-switch (pulsewidth modulation) model. The linear model is obtained by applying a small-signal perturbation to the corresponding averaged state-space description. The result shows that this quadratic converter exhibits the transfer characteristics of a fourth-order system. The resulting models are only valid in the continuous conduction mode (CCM). The validity of the proposed models was verified by computer simulation using PSPICE and MATLAB/SIMULINK for a specified converter. Experimental results on a prototype converter are also presented.