Analysis of Piecewise Constant Models of Current Mode Controlled DC-DC Converters

Buck, boost, and buck-boost converters constitute large class of dc-dc converters used in practice and are interesting nonlinear dynamical systems. It has been shown earlier that various nonlinear phenomena including subharmonics and chaos can be observed in these converters. In this paper we show that with the simplifying assumption that voltage regulation is achieved in high frequency modulation, a very simple dimensionless model can be derived that explains the dynamic phenomena in both continuous conduction mode as well as the discontinuous conduction mode. Using this model, we analyze some peculiar aspects of the dynamics in discontinuous conduction mode like the occurrence of superstable orbits.