| Titre : | Amélioration des Performances de la Commande Directe de Couple (DTC) de La Machine Asynchrone par des Techniques Non-Linéaires |
| Auteurs : | Abdelkarim AMMAR, Auteur ; Amor Bourek, Directeur de thèse ; Abdehamid Benakcha, Directeur de thèse |
| Type de document : | Monographie imprimée |
| Editeur : | Biskra [Algerie] : Université Mohamed Kheider, 2017 |
| Langues: | Français |
| Mots-clés: | Moteur asynchrone,commande directe de couple,Modulation vectorielle,commande non linéaire,commande par mode glissant,Observateur,Basse vitesse,Optimisation de rendement |
| Résumé : |
RESUME :
La commande directe de couple (DTC) a été proposée en tant qu'alternative de la commande vectorielle au milieu des années 1980 pour les machines à courant alternatif. Cette stratégie repose sur la détermination directe des états de commutation de l'onduleur et offre un schéma plus simple et moins sensible aux paramètres de la machine. Cependant, la fréquence de commutation variable de la DTC provoque des ondulations élevées de flux et de couple qui conduisent à un bruit acoustique et dégradent les performances de la commande, en particulier dans les faibles vitesses. Dans le but d'améliorer les performances de la DTC pour le moteur asynchrone, cette thèse a abordé les points les plus importants concernant cette problématique. La réduction des ondulations, qui sont les inconvénients principaux, par l’application d’une fréquence de commutation constante en utilisant la modulation vectorielle (SVM) a été effectuée au premier lieu. Ensuite, nous avons présenté la conception d’une commande non linéaire basée sur la linéarisation entrée-sortie et la commande par mode glissant pour assurer un contrôle robuste contre les différentes incertitudes et les perturbations externes. De plus, la commande sans capteur peut augmenter la fiabilité et diminuer le coût du système. Pour cela, nous avons présenté des structures d’observateur pour améliorer l'estimation de vitesse et du flux dans le fonctionnement à basse et haute vitesse. Enfin, nous avons discuté de l'insertion de la stratégie de minimisation des pertes pour l'optimisation de rendement basée sur l'ajustement online du flux produit en fonction de la charge. Les résultats de tous les aspects discutés de cette thèse ont été présentés par simulation numérique utilisant le logiciel Matlab/Simulink, en outre, une mise en œuvre en temps réel dans le laboratoire de génie électrique de Biskra (LGEB) équipé par la carte dSpace 1104 a été réalisé, des résultats expérimentaux ont été représentés afin de valider les résultats de simulation. ABSTRACT : The direct torque control (DTC) was proposed as an alternative to the vector control in the middle of 1980s for AC machines control. This strategy bases on the direct determination of inverter switching states and offers a simpler scheme and less sensitivity to machine parameters. However, the variable switching frequency of DTC causes high flux and torque ripples which lead to an acoustical noise and degrade the performance of the control technique, especially at low-speed regions. In the objective of improving the performance of DTC for the induction motor, this thesis addresses the most important points concerning this issue. The reduction of high ripples, which are the major drawbacks, by applying a constant switching frequency using the space vector modulation (SVM) has been done firstly. Then, we have presented a nonlinear control design based on input-output feedback linearization and sliding mode control to ensure a robust control against different uncertainties and external disturbances. Moreover, the sensorless control can increase the reliability and decrease the cost of the control system. Therefore, we have presented several observers structures to improve speed and flux estimation in high and low speed operations. Finally, we have discussed the insertion of losses minimization strategy for efficiency optimization based on the online adjusting of the produced flux according to the load value. The results of all the discussed aspects of this thesis have been obtained by numerical simulation using Matlab/Simulink software. Furthermore, a real-time implementation in the electrical engineering laboratory of Biskra (LGEB) equipped with dSpace 1104 is conducted. The experimental results have been depicted in order to validate the simulation results. |
| Sommaire : |
Dedication
Acknowledgments Abstract List of Publications List of figures List of tables Nomenclature Table of Contents General Introduction .................................................................................................................. 1 Chapter 01 State of The Art in Different Control Strategies for Induction machine 1.1 Introduction........................................................................................................................... 6 1.2. Background on Variable Speed Drives................................................................................ 7 1.2.1 Scalar control.................................................................................................................. 8 1.2.2 Field oriented control ..................................................................................................... 9 1.2.3 Direct torque control .................................................................................................... 10 1.2.3.1 Basic direct torque control and direct self-control ................................................ 10 1.2.3.2 Direct torque control with constant switching frequency...................................... 11 1.3 Nonlinear Control Techniques............................................................................................ 12 1.3.1 Feedback linearization.................................................................................................. 13 1.3.1.1 Input-output feedback linearization....................................................................... 13 1.3.1.2 Other linearization methods................................................................................... 14 1.3.1.3 Summary................................................................................................................ 14 1.3.2 Sliding Mode Control................................................................................................... 15 1.3.2.1 Brief Historical on sliding mode theory ................................................................ 15 1.3.2.2 Basic concepts of SMC.......................................................................................... 15 1.3.2.3 Chattering phenomenon......................................................................................... 16 1.3.2.4 High order sliding mode control............................................................................ 17 1.3.3. Survey on the application of nonlinear techniques for electrical machines control.... 18 1.4 Sensorless Control Techniques for Induction Motor.......................................................... 19 1.4.1 Open loop estimation methods (Estimators without feedback) ................................... 20 _______________________________________________________________________________________________________Table of Contents 1.4.1.1. Voltage model flux estimator ............................................................................... 20 1.4.1.2. Current model flux estimator................................................................................ 20 1.4.1.3. Rotor speed estimation ......................................................................................... 20 1.4.2 Model reference adaptive system (MRAS).................................................................. 21 1.4.3 Closed Loop Observers based on Machine State Reconstruction................................ 21 1.4.3.1 Adaptive observers ................................................................................................ 21 1.4.3.2 Extended Kalman filter.......................................................................................... 22 1.4.3.3 Sliding mode observers ......................................................................................... 23 1.5 Efficiency Optimization Based Control.............................................................................. 24 1.6 Conclusion .......................................................................................................................... 26 Chapter 02 Basic Direct Torque Control Methods for the Induction Motor Drive 2.1 Introduction......................................................................................................................... 27 2.2 Model of Induction Motor Dedicated for Direct Torque Control....................................... 27 2.3 Tow-Level Voltage Source Inverter (VSI) Model.............................................................. 28 2.4 Principles of Direct Torque Control ................................................................................... 29 2.4.1 Control of stator flux and electromagnetic torque ....................................................... 30 2.4.1.1 Control of stator flux ............................................................................................. 30 2.4.1.2 Control of electromagnetic torque......................................................................... 31 2.4.2 Estimation of stator flux and electromagnetic torque .................................................. 32 2.4.2.1 Stator flux estimation............................................................................................. 32 2.4.2.2 Electromagnetic torque estimation ........................................................................ 33 2.5 Switching Table Construction and Control Algorithm Design........................................... 33 2.5.1 Six sectors Switching table .......................................................................................... 33 2.5.2 DTC improvement using twelve sector switching table .............................................. 34 2.5.3 Speed regulation in DTC strategy ................................................................................ 36 2.5.4 Global scheme of basic direct torque control............................................................... 36 2.6 Constant Switching Frequency Direct Torque Control Using SVM .................................. 37 2.6.1 Space vector modulation algorithm.............................................................................. 38 2.6.2 Stator flux oriented (SFO) SVM-DTC strategy ........................................................... 40 2.7 Simulation Results .............................................................................................................. 41 2.7.1 Starting up and steady states with load application ..................................................... 41 2.7.2. Rotation sense reversing.............................................................................................. 45 _______________________________________________________________________________________________________Table of Contents 2.7.3. Low speed operation ................................................................................................... 47 2.8. Real-Time Control of Induction Motor.............................................................................. 49 2.9. Experimental Results: ........................................................................................................ 50 2.9.1. Starting up and steady states with load application..................................................... 50 2.9.2. Speed sense reversing: ................................................................................................ 54 2.10.3. Low speed operation ................................................................................................. 55 2.10 Comparative evaluation of direct torque control techniques ............................................ 56 2.11. Conclusion ....................................................................................................................... 57 Chapter 03 Nonlinear SVM-DTC Using Feedback Linearization and Sliding Mode Control 3.1 Introduction:........................................................................................................................ 58 3.2 Nonlinear Control Strategies............................................................................................... 59 3.2.1 Input-output feedback linearization (IOFL) approach ................................................. 59 3.2.1.1 Relative degree and lie derivatives:....................................................................... 59 3.2.1.2 Control design........................................................................................................ 60 3.2.2 Application of IOFL on direct torque control for IM drive (IOFL-DTC) ................... 61 3.2.2.1 Model presentation ................................................................................................ 61 3.2.2.2 IOFL-DTC control design ..................................................................................... 61 3.2.2.3 Feedback linearization improvement..................................................................... 64 3.2.3 Sliding mode control .................................................................................................... 64 3.2.3.1 Sliding surface choice............................................................................................ 64 3.2.3.2 Existence conditions of sliding mode.................................................................... 65 3.2.3.3 Control design........................................................................................................ 65 3.2.4 Second order sliding mode control............................................................................... 67 3.2.4.1 Twisting control..................................................................................................... 67 3.2.4.2 Sub-optimal control ............................................................................................... 68 3.2.4.3 Super twisting control............................................................................................ 68 3.2.5 Application of first order sliding mode control on direct torque control ..................... 69 3.2.6 Improved direct torque control using second order sliding mode control ................... 71 3.2.6.1 First order SM-speed controller design ................................................................. 71 3.2.6.2 Second order SM-speed controller design............................................................. 72 3.3. Simulation Results ............................................................................................................. 73 _______________________________________________________________________________________________________Table of Contents 3.3.1. SFOC SVM-DTC and nonlinear SMFL-DTC starting up and steady states .............. 73 3.3.2 Robustness test of parameters variation in low speed region....................................... 75 3.3.3. PI and super twisting speed (STSC) controllers comparative analysis....................... 77 3.4. Experimental Results ......................................................................................................... 79 3.4.1 SFOC SVM-DTC and nonlinear SMFL-DTC starting up and steady states ............... 79 3.4.2 PI and super twisting speed controller (STSC) comparative analysis ......................... 82 3.4.3 Low speed operation .................................................................................................... 83 3.5 Summarized comparative evaluation of control techniques ............................................... 84 3.6. Conclusion ......................................................................................................................... 84 Chapter 04 Estimation and Sensorless Control for DTC Controlled Induction Motor 4.1 Introduction......................................................................................................................... 86 4.2. Open-Loop Flux Estimation .............................................................................................. 86 4.2.1 Conventional stator flux estimation ............................................................................. 87 4.2.2 Solution 1: Modified flux estimator............................................................................. 87 4.2.3 Solution 2: Current-model based flux estimator .......................................................... 88 4.3 Closed-Loop Estimation of The Induction Motor (Sensorless control) ............................. 89 4.3.1 Definition: observability and observers ....................................................................... 89 4.3.2 Observers based on machine state reconstruction........................................................ 89 4.3.3 Model reference adaptive system MRAS..................................................................... 90 4.4. Limits of Sensorless Control in Low-Speed Operation Condition .................................... 90 4.4.1 Signal acquisition errors............................................................................................... 90 4.4.2 Inverter non-linearity.................................................................................................... 91 4.4.3 Distortions in the flux angle......................................................................................... 91 4.4.4 Incorrect speed estimation............................................................................................ 91 4.4.5 Delay due to filtering.................................................................................................... 91 4.5 Sensorless Control Design for Nonlinear SVM-DTC Strategy .......................................... 91 4.5.1 Full order adaptive observer for DTC controlled IM................................................... 92 4.5.2 Sliding mode flux observer for DTC controlled IM .................................................... 94 4.5.2.1 Sliding mode flux observer design ........................................................................ 94 4.5.2.2 Gain selection ........................................................................................................ 95 4.5.2.3 Speed estimatation................................................................................................. 95 4.5.3 Second order sliding mode load torque observer ......................................................... 96 _______________________________________________________________________________________________________Table of Contents 4.6. Operating Conditions and Benchmarks ............................................................................. 97 4.7 Simulation and Experimental Comparative Study.............................................................. 98 4.7.1 Simulation results......................................................................................................... 98 4.7.1.1 Starting up and steady state ................................................................................... 98 4.7.1.2 Low speed operations ............................................................................................ 99 4.7.1.3 Zero speed operation and industrial benchmark test ........................................... 101 4.7.1.4 Parameters variation test...................................................................................... 103 4.7.1.6 Load torque estimation ........................................................................................ 104 4.7.2 Experimental results................................................................................................... 104 4.7.2.1 Starting up and steady state ................................................................................. 105 4.7.2.2 Low speed operation............................................................................................ 106 4.7.2.3 Zero speed operation and industrial benchmark test ........................................... 107 4.7.2.4 Load torque estimation ........................................................................................ 108 4.8 Association of MRAS with stator flux SMO for speed estimation .................................. 109 4.8.1 Simulation results....................................................................................................... 110 4.8.2 Experimental results................................................................................................... 112 4.9 Conclusion ........................................................................................................................ 113 Chapter 05 Efficiency Optimization of The IM Controlled by Nonlinear SVM-DTC Strategy 5.1. Introduction...................................................................................................................... 114 5.2. Steady State Performance, Power Losses and Efficiency of The IM .............................. 115 5.2.1 Per phase equivalent circuit of IM ............................................................................. 115 5.2.2 Power Losses of IM.................................................................................................... 115 5.2.2.1 Stator and rotor copper losses.............................................................................. 115 5.2.2.2 Core losses .................................................................................................................. 116 5.2.2.3 Mechanical losses................................................................................................ 116 5.2.2.4 Stray load losses .................................................................................................. 116 5.2.2.5 Converters losses ................................................................................................. 117 5.2.3 Induction motor efficiency and power factor............................................................. 117 5.3. Efficiency Optimization Methods of IM.......................................................................... 118 5.3.1 Search control (SC) .................................................................................................... 118 _______________________________________________________________________________________________________Table of Contents 5.3.2. Loss model based controller (LMC) ......................................................................... 118 5.4 Application of Losses Minimization with Nonlinear DTC Control Scheme.................... 119 5.4.1 Induction motor loss model in (d, q) reference frame................................................ 119 5.4.2 Loss minimization algorithm ..................................................................................... 120 5.4.3 The optimal choice of flux level ................................................................................ 121 5.5 Simulation Results ............................................................................................................ 122 5.6 Experimental Results ........................................................................................................ 125 5.6.1 Starting up, steady state and load application ............................................................ 125 5.6.2 Application of different load values in steady state ................................................... 126 5.7. Conclusion ....................................................................................................................... 128 General Conclusion ................................................................................................................ 130 Appendix References |
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| Cote | Support | Localisation | Statut | Emplacement | |
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| TH/0806 | Thèse de doctorat | BIB.FAC.ST. | Empruntable | Magazin |
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