Backstepping Control Based on a Third-order Sliding Mode Controller to Regulate the Torque and Flux of Asynchronous Motor Drive

This work represents a new nonlinear control for the asynchronous motor (AM) drive. The designed nonlinear control is based on the combination between the backstepping control (BC) scheme and third-order sliding mod control (TOSMC). In this proposed nonlinear control, the torque and flux are controlled. Also, the torque, current, and flux ripples are minimized by a proposed BC-TOSMC strategy. The proposed BC-TOSMC strategy is more robust compared to the field-oriented control (FOC). The proposed BC-TOSMC strategy of AM drive has been simulated in MATLAB/Simulink software. The comparisons were made between the proposed BC-TOSMC strategy and the FOC strategy under different operating conditions. The results show that the proposed BC-TOSMC strategy minimized the flux, current, and torque ripples of the AM drive compared to the FOC strategy, with a reduction torque ripples ratio of about 57.14%. Also, the total harmonic distortion (THD) values of stator current using the proposed BC-TOSMC strategy and FOC technique are respectively 1.09% and 3.42%. In this case, utilizing the proposed BC-TOSMC strategy, the performance of the AM has improved from the FOC strategy

Improved Backstepping Control of a DFIG based Wind Energy Conversion System using Ant Lion Optimizer Algorithm

In this paper, an improved Backstepping control based on a recent optimization method called Ant Lion Optimizer (ALO) algorithm for a Doubly Fed Induction Generator (DFIG) driven by a wind turbine is designed and presented. ALO algorithm is applied for obtaining optimum Backstepping control (BCS) parameters that are able to make the drive more robust with a faster dynamic response, higher accuracy and steady performance. The fitness function of the ALO algorithm to be minimized is designed using some indexes criterion like Integral Time Absolute Error (ITAE) and Integral Time Square Error (ITSE). Simulation tests are carried out in MATLAB/Simulink environment to validate the effectiveness of the proposed BCS-ALO and compared to the conventional BCS control. The results prove that the objectives of this paper were accomplished in terms of robustness, better dynamic efficiency, reduced harmonic distortion, minimization of stator powers ripples and performing well in solving the problem of uncertainty of the model parameter

Attous D, “Sliding Mode Controls of Active and Reactive Power of a DFIG with MPPT for Variable Speed Wind Energy Conversion

Abstract: This paper presents the study of a variable speed wind energy conversion system based on a Doubly Fed Induction Generator (DFIG) based on a sliding mode control applied to achieve control of active and reactive powers exchanged between the stator of the DFIG and the grid to ensure a Maximum Power Point Tracking (MPPT) of a wind energy conversion system. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the PWM converter. To extract a maximum of power, the rotor side converter is controlled by using a stator flux-oriented strategy. The created decoupling control between active and reactive stator power allows keeping the power factor close to unity. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed

Contribution à l’Etude et à la Commande Robuste d’un Aérogénérateur Asynchrone à Double Alimentation

Dans le cadre de la recherche croissante à des nouvelles sources de production d’énergie électrique parmi elles les énergies renouvelables, cette thèse présente une contribution à l’étude et à la commande robuste de l’aérogénérateur asynchrone à double alimentation à pour objectif d’exploiter de l’énergie du vent pour produire d’une énergie propre sans pollution. Tout d’abord, nous avons exposé les modèles mathématiques de chaque élément de l’aérogénérateur (la turbine éolienne et sa commande MPPT + le générateur et sa commande vectorielle). Pour optimisé les gains des régulateurs classiques PI pour obtenir des bonnes performances, nous cherchons à déterminer les coefficients des régulateurs PI utilisés pour la commande vectorielle du générateur asynchrone à double alimentation sans le recours aux méthodes analytiques classiques pour le calcul des ces derniers. Pour ceux-ci nous essayons de développer un algorithme par la méthode d’essaim de particules (PSO) tout en visualisant la fonction objectif (fitness) dont on cherche à minimiser l’erreur dans un système asservi entre le signal d’entrée et le signal de sortie. Les lois de commande classique du type PI appliquées au générateur asynchrone à double alimentation donnent des bons résultats dans le cas des systèmes linéaires à paramètres constants. Pour des systèmes non linéaires où ayant des paramètres non constants, ces lois de commande classique peuvent être insuffisantes car elles sont non robustes. Pour cela on doit faire appel à des lois de commande insensibles aux perturbations et aux cas non linéaires. La commande par mode glissant est par sa nature une commande non linéaire constituent une bonne solution à ces problèmes liés à la commande classique. Dans la dernière partie de cette thèse, nous avons appliqué la commande par mode glissant pour contrôler la puissance active et réactive avec l’utilisation d’un onduleur commandé par la technique SVM pour améliorer la qualité d’énergie électrique pour injecter cet énergie au réseau électrique où la simulation a été effectué sous l’environnement Matlab/Simulink. Les résultats de simulation obtenus par l’application de la commande par mode glissant à l’aérogénérateur asynchrone à double alimentation sont considérablement acceptables

Robust synergetic-sliding mode-based-backstepping control of induction motor with MRAS technique

This paper proposes a new speed control of an induction motor (IM) drive, which is based the combination between the backstepping control (BC) and synergetic-sliding mode controller (SSMC). In addition, it was proposed to use the Model Reference Adaptation System (MRAS) to estimate the IM speed with the aim of reducing speed error and increasing the performance and efficiency of the proposed system. IM has already been considered for many applications, especially traction systems that mainly use proportional-integral controllers. However, such types of controllers do not handle well in the event of a system malfunction. These may reduce the performance of the control system. Therefore, a robust nonlinear control, namely BC-SSMC with MRAS, is proposed. This control relies on combining the advantages of both BC and SSMC to control the IM speed. Also, the MRAS was used to replace the speed sensor with the aim of reducing the periodic maintenance of this sensor and thus reducing the size and cost of the system. The robustness of the BC-SSMC-MRAS was analyzed with respect to the occurrence of system malfunctions, as it is considered the most robust compared to BC. The simulation results performed on the 1.5 kW IM showed the effectiveness of the BC-SSMC-MRAS in enhancing the system durability, reducing the torque ripples and improving the current quality. In all tests performed, the speed overshoot value was improved by 100 % compared to the BC. Also, the torque and flux ripples in the event of a machine malfunction are improved by 50 % and 77.14 %, respectively, compared to the BC. In the speed change test, the response time and steady-state error of speed values were improved by 5.26 % and 67.56 %, respectively. So all these ratios prove the superiority of the BC-SSMC-MRAS over the BC in terms of improving system performance

Predictive torque control of induction motor for rotor bar faults diagnosis

Unlike DC motors and synchronous motors, they are maintenance-free motors due to the absence of brushes, commutators and slip rings. Induction motors can be operated in polluted and explosive environments as they do not have brushes which can cause sparks. In this paper, the performance of two control techniques, namely direct torque control (DTC) and predictive torque control (PTC), are compared in transient and static states when applied to a faulty induction machine (IM). The current and torque ripples is evaluated in a healthy machine, as well as in the presence of faults, at various speed and load values. During the transient state, the objective is to assess the method that provides the optimal dynamic response, which is achieving the desired speed without any overshooting while during the static state, the objective is to minimize torque ripple and harmonics in the stator current. The Discrete Wavelet Transform (DWT) is used to analyze stator phase current. In addition, the energy eigen value (EEV) analysis has been used to determine the fault severity. The healthy and faulty systems are simulated using Matlab/Simulink for the two control methods. The results show the superiority of the PTC method compared to the DTC. A comparison of the proposed control method with other works reported in the literature is performed to verify the superiority of the proposed strategy.</p