Robust sigma-delta generalised proportional integral observer based control of a 'buck' converter with uncertain loads Article uri icon

abstract

  • This article describes the design of an observer based robust linear output feedback controller for the regulation and output reference trajectory tracking tasks in switched %27buck%27 converter circuits feeding a completely unknown time-varying load. The state-dependent perturbation effects of the unknown load resistance are on-line estimated by means of a generalised proportional integral (GPI) observer, which represents the dual counterpart of GPI controllers introduced in Fliess, Má rquez, Delaleau and Sira-Ramí rez (Fliess, M., Má rquez, R., Delaleau, E., and Sira-Ramí rez, H. (2002), %27Correcteurs Proportionnels-inté graux Gé neralisé s%27, ESAIM: Control, Optimisation and Calculus of Variations, 7, 23-41). The reconstructed perturbation complements the controller in a cancellation effort which allows the core of the feedback controller to become a traditional proportional derivative (PD) controller. The designed average feedback controller is then implemented via a sigma-deltamodulator, which effectively translates the designed continuous average feedback control input signal into a discrete valued switched input signal driving the converter%27s input switch and preserving all relevant features of the average design. The Appendix collects some generalities about GPI observers. © 2010 Taylor %26 Francis.
  • This article describes the design of an observer based robust linear output feedback controller for the regulation and output reference trajectory tracking tasks in switched 'buck' converter circuits feeding a completely unknown time-varying load. The state-dependent perturbation effects of the unknown load resistance are on-line estimated by means of a generalised proportional integral (GPI) observer, which represents the dual counterpart of GPI controllers introduced in Fliess, Má rquez, Delaleau and Sira-Ramí rez (Fliess, M., Má rquez, R., Delaleau, E., and Sira-Ramí rez, H. (2002), 'Correcteurs Proportionnels-inté graux Gé neralisé s', ESAIM: Control, Optimisation and Calculus of Variations, 7, 23-41). The reconstructed perturbation complements the controller in a cancellation effort which allows the core of the feedback controller to become a traditional proportional derivative (PD) controller. The designed average feedback controller is then implemented via a sigma-deltamodulator, which effectively translates the designed continuous average feedback control input signal into a discrete valued switched input signal driving the converter's input switch and preserving all relevant features of the average design. The Appendix collects some generalities about GPI observers. © 2010 Taylor %26 Francis.

publication date

  • 2010-01-01