Observability and observer design for hybrid multicell choppers

Francisco Bejerano (1) , Malek Ghanes (2) , Jean-Pierre Barbot (1, 2)

1 NON-A - Non-Asymptotic estimation for online systems
2 ECS-Lab - Électronique et Commande des Systèmes Laboratoire

Multicell choppers are part of a class of hybrid systems in which the continuous state vector is always unob- servable, in the sense that the observability matrix has never full rank. Due to their hybrid behavior, the recent concept of Z(TN)-observability can be applied and analyzed in the context of multicell choppers; which allows to give conditions, in terms of the switching sequence, under which the voltage across each capacitor can be reconstructed, not instantly, but after some number of switchings. It is also considered the case when a DC- motor is coupled to the multicell chopper. In this case, it is shown, that under certain admissible assumptions, the voltages across the capacitors and the speed of the motor can be acceptably estimated. Two observers, one based on the super-twisting algorithm and the other one based on an adaptive approach, are designed. Additionally, we design an observer for the partial state observation. Simulations are given where the proposed observers are compared and their effectiveness is shown.

Mots clés: Hybrid systems; Observability; Multicell choppers

Domaines: Automatique

Francisco Bejerano, Malek Ghanes, Jean-Pierre Barbot. Observability and observer design for hybrid multicell choppers. International Journal of Control, 2010, 83 (3), ⟨10.1080/00207170903334821⟩. ⟨hal-00640515⟩