|Control of Chaos in SEPIC DC-DC Converter
Anbukumar Kavitha and Govindarajan Uma
International Journal of Control, Automation, and Systems, vol. 8, no. 6, pp.1320-1329, 2010
Abstract : DC-DC converters are widely used in power electronic systems where there is a need for stabilizing a given dc voltage to a desired value. It has been reported that DC-DC converters exhibit different non-linear phenomena including bifurcations, quasi-periodicity and chaos under both voltage mode and current mode control schemes. In this work, current mode controlled SEPIC converter operating in continuous conduction mode is considered and by varying the reference current Iref, the converter exhibits chaos. It has been observed that the system changes from a stable buck-like operation to an unstable boost-like operation by varying Iref. Bifurcation diagram is plotted for control signal and capacitor voltage with Iref as bifurcation parameter. Resonant parametric perturbation control tech-nique has been applied to suppress chaos. Effects of phase shift and frequency mismatch are also analyzed. With phase shift, control power required for suppressing chaos has been reduced. Also intermittent chaotic stages are suppressed with the effect of frequency mismatch at the expense of increasing control power. The stability analysis in SEPIC converter is performed by means of discrete model and is validated through the simulated and experimental results.
Keyword : Bifurcation, chaos, current programmed control, resonant parametric perturbation and SEPIC DC-DC converter.