Hybrid cancellation of ripple disturbances arising in AC/DC converters

Andrea Bisoffi (1) , Luca Zaccarian (2, 3) , Mauro da Lio (1) , Carnevale Daniele

1 UNITN - Università degli Studi di Trento = University of Trento
2 Dipartimento di Ingegneria Industriale [Trento]
3 LAAS-MAC - Équipe Méthodes et Algorithmes en Commande

In AC/DC converters, a peculiar periodic nonsmooth waveform arises, the so-called ripple. In this paper we propose a novel model that captures this nonsmoothness by means of a hybrid dynamical system performing state jumps at certain switching instants, and we illustrate its properties with reference to a three phase diode bridge rectifier. As the ripple corrupts an underlying desirable signal, we propound two observer schemes ensuring asymptotic estimation of the ripple, the first with and the second without knowledge of the switching instants. Our theoretical developments are well placed in the context of recent techniques for hybrid regulation and constitutes a contribution especially for our second observer, where the switching instants are estimated. Once asymptotic estimation of the ripple is achieved, the ripple can be conveniently canceled from the desirable signal, and thanks to the inherent robustness properties of the proposed hybrid formulation, the two observer schemes require only that the desirable signal is slowly time varying compared to the ripple. Exploiting this fact, we illustrate the effectiveness of our second hybrid observation law on experimental data collected from the Joint European Torus tokamak.

Mots clés: tokamak plasma; ripple; hybrid dynamical system; power system; hybrid observer

Domaines: Automatique / Robotique

Andrea Bisoffi, Luca Zaccarian, Mauro da Lio, Carnevale Daniele. Hybrid cancellation of ripple disturbances arising in AC/DC converters. Automatica, 2017, 77, pp.344-352. ⟨hal-01851132⟩