Control of Bifurcation Behaviour of the Buck Converter via a Resonant Parametric Perturbation Circuit

Abstract

Nonlinear circuits and systems research has been growing very quickl y over the past two decades. Activel y pursued in almost every branch of science and engineering, nonlinear systems theory luis found wide applications in a variety of practical engineering problems. Engineers, scientists and mathematicians have similarly advanced from the passive role of simpl y anal yzing, or identifying chaos to their present, active involvement in controlling chaos — control directed not onl y at suppression, but also at exploiting its enormous potential. We now stand at the threshold ofmajor advances in the control and synchronization of cluios for new applications across the range of engineering disciplines. All feedback controlled power converters exhibit certain non-linear phenomena over a specific breadth of parameter values. Despite being commonly encountered hy power electronics engineers, these non-linear phenomena are by and large not thoroughl y understood by engineers. Such phenomena remaining somewhat mysterious and hardl y ever been examined in a formal way. As the discipline of power electronics becomes more matured, demand for better functionality, dependability and performance of power electronics circuits will inevitably force researchers to engage themselves in more detailed stud y and analysis of non-linear phenomena and complex behaviour of power electronics converters. The bifurcation behaviour of the back converter occurs when the input voltage is varied. In this study, the computer simulation scheme, PSPICE is employed to model the behaviour of the ideal back converter. For certain values of the input voltage Vin instability occurs. The resonant parametric perturbation method is then applied to control the bifurcation behaviour of the voltage-mode controlled back converter. Analysis and simulations are presented to provide theoretical and practical evidence for the proposed control method. As the back converter has wide industrial application, it would be deemed necessary for designers to know about its bifurcation behaviour and how to control such behaviour.