Robust nonlinear generalized predictive control of a permanent magnet synchronous motor with an anti-windup compensator

This paper presents a robust nonlinear generalized predictive control (RNGPC) strategy applied to a permanent magnet synchronous motor (PMSM) for speed trajectory tracking and disturbance rejection. The nonlinear predictive control law is derived by using a newly defined design cost function. The Taylor series expansion is used to carry out the prediction in a finite horizon. No information about the external perturbation and parameters uncertainties are needed to ensure the robustness of the proposed RNGPC. Moreover, to maintain the phase current within the limits using saturation blocks, a cascaded structure is adopted and an anti-windup compensator is proposed. The validity of the proposed control strategy is implemented on a dSPACE DS1104 board driving in real-time a 0.25 kW PMSM. Experimental results have demonstrated the stability, robustness and the effectiveness of the proposed control strategy regarding trajectory tracking and disturbance rejection

Robust nonlinear predictive controller for multivariable nonlinear systems with different relative degree

This paper presents a robust nonlinear generalized predictive control (RNGPC) strategy applied to a permanent magnet synchronous motor (PMSM) for speed trajectory tracking and disturbance rejection. The nonlinear predictive control law is derived by using a newly defined design cost function. The Taylor series expansion is used to carry out the prediction in a finite horizon. No information about the external perturbation and parameters uncertainties are needed to ensure the robustness of the proposed RNGPC. Moreover, to maintain the phase current within the limits using saturation blocks, a cascaded structure is adopted and an anti-windup compensator is proposed. The validity of the proposed control strategy is implemented on a dSPACE DS1104 board driving in real-time a 0.25 kW PMSM. Experimental results have demonstrated the stability, robustness and the effectiveness of the proposed control strategy regarding trajectory tracking and disturbance rejection

Robust nonlinear generalised predictive control for a class of uncertain nonlinear systems via an integral sliding mode approach

In this paper, a robust nonlinear generalised predictive control (GPC) method is proposed by combining an integral sliding mode approach. The composite controller can guarantee zero steady-state error for a class of uncertain nonlinear systems in the presence of both matched and unmatched disturbances. Indeed, it is well known that the traditional GPC based on Taylor series expansion cannot completely reject unknown disturbance and achieve offset-free tracking performance. To deal with this problem, the existing approaches are enhanced by avoiding the use of the disturbance observer and modifying the gain function of the nonlinear integral sliding surface. This modified strategy appears to be more capable of achieving both the disturbance rejection and the nominal prescribed specifications for matched disturbance. Simulation results demonstrate the effectiveness of the proposed approach

Robust nonlinear generalized predictive control of a permanent magnet synchronous motor with an anti-windup compensator

This paper presents a robust nonlinear generalized predictive control (RNGPC) strategy applied to a permanent magnet synchronous motor (PMSM) for speed trajectory tracking and disturbance rejection. The nonlinear predictive control law is derived by using a newly defined design cost function. The Taylor series expansion is used to carry out the prediction in a finite horizon. No information about the external perturbation and parameters uncertainties are needed to ensure the robustness of the proposed RNGPC. Moreover, to maintain the phase current within the limits using saturation blocks, a cascaded structure is adopted and an anti-windup compensator is proposed. The validity of the proposed control strategy is implemented on a dSPACE DS1104 board driving in real-time a 0.25 kW PMSM. Experimental results have demonstrated the stability, robustness and the effectiveness of the proposed control strategy regarding trajectory tracking and disturbance rejection

Offset-free feedback linearisation control of a three-phase grid-connected photovoltaic system

In this study, a state feedback control law is combined with a disturbance observer to enhance disturbance rejection capability of a grid-connected photovoltaic (PV) inverter. The control law is based on input-output feedback linearisation technique, while the existing disturbance observer is simplified and adopted for the system under investigation. The resulting control law has a proportional-integral (PI)/almost PI-derivative-like structure, which is convenient for real-time implementation. The objective of the proposed approach is to improve the DC-bus voltage regulation, while at the same time control the power exchange between the PV system and the grid. The stability of the closed-loop system under the composite controller is guaranteed by simple design parameters. Both simulation and experimental results show that the proposed method has significant abilities to initiate fast current control and accurate adjustment of the DC-bus voltage under model uncertainty and external disturbance

Contribution à la commande prédictive non linéaire d'une machine synchrone à aimants permanents

Le travail de recherche présenté dans cette thèse est consacré à la commande non linéaire associée à la commande prédictive en temps continu pour la machine synchrone à aimants permanents. Cette machine est connue pour sa grande puissance massique, ce qui lui confère une place importante dans des applications embarquées. Cependant, son modèle multivariable et non linéaire, ces paramètres qui peuvent varier dans le temps et sa dynamique rapide rendent sa commande plus compliquée. Le défi majeur de notre travail de recherche est de concevoir une loi de commande pour la machine synchrone à aimants permanents plus performante au niveau de la poursuite de trajectoires, du rejet de perturbations, de la stabilité, de la robustesse vis-à-vis des incertitudes paramétriques, du respect des contraintes physiques et du temps de calcul, et ce, tout en conservant l'aspect non linéaire. Dans ce cadre, la commande prédictive se présente alors comme une solution idéale. Toutefois, les contrôleurs prédictifs non linéaires conçus à partir du modèle à temps discret requièrent un temps de calcul important, ce qui limite leurs applications à des systèmes non linéaires à dynamique lente. Le développement des nouvelles techniques de commande prédictive non linéaire basées sur le modèle à temps continu a permis de réduire considérablement le temps de calcul. Parmi ces techniques, l'utilisation de l'expansion en séries de Taylor pour concevoir un modèle de prédiction à partir du modèle à temps continu. Les contrôleurs obtenus sont alors analytiques et faciles à implanter sur des processeurs numériques de signaux. Cependant, il est connu que cette stratégie souffre du manque de robustesse vis-à-vis des perturbations externes et des imperfections du modèle. À cet effet, nous avons proposé un observateur permettant d'estimer toutes les perturbations qui peuvent affecter la régulation des sorties. La combinaison de la commande prédictive non linéaire avec l'observateur de perturbations permet de garantir la robustesse par rapport à la variation de tous les paramètres de la machine et à celle du couple de charge. D'un autre côté, il arrive fréquemment que les variables manipulées soient limitées par des blocs de saturation. En effet, la prise en compte des blocs limiteurs dans la conception des estimateurs de perturbation conduit systématiquement à l'apparition d'un schéma anti- saturation dans la boucle de commande. Nous proposons, de plus, une nouvelle loi de commande prédictive non linéaire permettant d'assurer la robustesse de systèmes non linéaires, et ce, en s'affranchissant de l'utilisation des estimateurs de perturbations. Pour chaque type de commande, deux variantes sont proposées. Une commande directe pour le contrôle de la machine avec la vitesse de rotation et la composante directe du courant comme sorties, et une commande en cascade basée sur l'imbrication d'une boucle interne de courants et une boucle externe de vitesse. La validation expérimentale de ces lois de commandes non linéaires a permis de tester leurs performances réelles en matière de suivi de trajectoires, de robustesse et de respect des contraintes électromagnétiques, et d'approuver la faisabilité et l'originalité de l'approche. Nous pensons que ce travail de recherche contribuera d'une façon non négligeable à l'avancée de la recherche dans le domaine de la commande prédictive non linéaire des machines électriques

Nonlinear predictive controller for a permanent magnet synchronous motor drive

A nonlinear predictive controller (NPC) for a permanent magnet synchronous motor (PMSM) is proposed in this paper. Its objective is high performance tracking of the rotor speed trajectory while maintaining the d-axis component of the armature current at zero. The load torque and the mismatched parameters are considered to be unknown perturbations. To ensure robustness against these perturbations, a disturbance observer is designed using a new gain function, and integrated into the control law. The combination of the nonlinear predictive controller and the disturbance observer works as a nonlinear controller. The overall closed-loop system is proved to be globally asymptotically stable depending on the design parameters. The validity of the proposed controller was tested by simulations. Satisfactory results were obtained with respect to the tracking of the speed trajectory and disturbance rejection

Robust continuous generalized predictive control of a permanent magnet synchronous motor drive

A robust generalized predictive controller (GPC) with a disturbance observer for a permanent magnet synchronous motor (PMSM) is presented. The proposed GPC controller combines the linear predictive control techniques together with the disturbance observer, which is designed to take into account the load torque variations and uncertain electrical and mechanical parameters. Stability of the closed-loop system is guaranteed and the controller is easy to implement. The system performance is tested with an experimental setup consisting of a PMSM and dSPACE DS1104 Board. A good speed tracking performance with no error is obtained while the d-axis current regulation is satisfactorily guaranteed