Η παρούσα διπλωματική εργασία αποτελεί μια μελέτη επί του ελέγχου των κινητήρων επαγωγής που στόχο έχει τη διερεύνηση της επίδασης των διαφορετικών σημάτων ανάδρασης (ανάλογο στροφών και ανάλογο του τετραγώνου στοφών) στην απόκριση του συστήματος κίνησης. Για το σκοπό αυτό αναπτύχθηκε ενδελεχώς η σχετική θεωρία, μελετήθηκε η παθητικότητα ηλεκτρομηχανικών συστημάτων, χρησιμοποιήθηκε συγκεκριμένος ηλεκτρονικός μετατροπέας και κατασκευάστηκε μετατροπέας σήματος συνεχούς ρεύματος ανάλογος του αριθμού των στροφών και του τετραγώνου του. Στα πλαίσια της εργασίας εξετάστηκε PI έλεγχος βασισμένος στον βαθμωτό (Scalar V/f) έλεγχο, με σήμα αρνητικής ανάδρασης ρεύμα ανάλογο του αριθμού και του τετραγώνου του αριθμού των στροφών. Μελετήθηκε η απόκριση του κινητήρα και για τους δύο ελέγχους για διαφορετικές τιμές των παραμέτρων KP και KI, και διερευνήθηκε ποιες είναι αυτές ώστε να έχουμε βέλτιστη απόκριση. Συγκεκριμένα ποιες παρουσιάζουν την μικρότερη υπερύψωση, τον μικρότερο χρόνο αποκατάστασης, το μικρότερο σφάλμα μόνιμης κατάστασης. Επίσης εξετάστηκε η επίδραση της κάθε παραμέτρου στην διαμόρφωση της εσωτερικής ενέργειας του κινητήρα. / This diploma thesis forms a study on control techniques of induction motors which comes with the intention to explore the effets of different signals of feedback (proportional to the number of revolutions and to the square of the number of revolutions) on the output of the motor. For this purpose sedulous analysis of relevant theory was carried out, passivity of electromechanical systems was studied, a specific electronic commutator was used and a converter of constant current signal proportional to the number of revolutionsand to the square of the number of revolutions was developed. In this thesis a PI controller based on the Scalar V/f control with a signal of current of negative feedback was examined. The output of the motor for both the controls aid for different values of the parameters KP and KI was examined, and it was investigated which of them lead to an optimal output of the motor. It was studied more specifically which of them result in the optimal overshoot, settling time and the error of the permanent mode. Furthermore, it was inquired the impact of its parameter on the modulation of the intrinsic power of the motor.

Energy efficiency optimization of electric machines is an important research field and is part of the objectives of several international projects such as the European Commission Climate and Energy package which has set itself a 20% energy savings target by 2020, and was extended for 2030 with higher targets. Therefore, this thesis proposes an efficiency optimization method of the Induction Machine (IM) through the variation of the control parameters. To achieve this goal, the flux in the airgap is modified according to an optimal flux table computed off-line for all possible operating points. The flux table is calculated with the best possible accuracy through an improved dynamic model of the IM, developed in these works. The latter avoids the main drawback of the classic dynamic model, by considering the effect of core losses. The core loss model established by Bertotti is used. It depends on the frequency and the amplitude of the magnetic field. The losses are then represented by a variable resistor, continuously evaluated according to the operating point. The established optimal flux table is a function of the operating conditions in terms of torque and speed. Indeed, the results show that the flux can be optimized for torque values less than about half the rated torque, and that this threshold is influenced by the speed. The proposed optimization method is simulated, then tested for the scalar control and the field-oriented control, in order to show the genericity of the proposed approach. The validation is carried on an experimental test bench for two 5.5 kW induction motors of different efficiency standards (IE2 and IE3). The results obtained show the reduction of the losses in the motor, thus an improvement of the overall efficiency while preserving a satisfactory dynamic behavior. Consequently, the optimization of the energy efficiency is validated for the two control structures and for the two studied motors. In addition to the validation of the simulation results, the proposed approach is compared to existing methods to assess its effectiveness

In industrial drives market, requirements related to control quality and price of drives are important. In low cost drives, one of the aims is achieving speed estimation accuracy. Since motor parameters are required to estimate speed and sometimes it is impractical to do no-load and locked rotor tests, it is necessary to estimate motor parameters from motor label or by simple measurements. Throughout this study, some of parameter estimation and speed estimation methods found in literature are investigated and some new methods are proposed. These methods are applied to three induction motors and estimation results are compared with test results. Advantages and disadvantages of these methods are investigated. As a result of this study, the most suitable parameter and speed estimation methods amongst these methods are obtained for low cost motor drives.

Orientador: Edson Bim / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T11:16:01Z (GMT). No. of bitstreams: 1 Bertonha_LeandroCorrea_M.pdf: 4817108 bytes, checksum: 7377641ea7817b2bac41b6c4870c60b2 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho é apresentada a implementação de uma estratégia de controle escalar V/f que mantém o fluxo de entreferro constante em seu valor nominal a partir do controle da relação entre a tensão de terceira harmônica, do estator, presente devido à saturação magnética, e da freqüência elétrica. No caso das bobinas de estator estarem conectadas em Y, a terceira harmônica de tensão é obtida a partir da soma das tensões de fase do estator. Na. presente proposta não é necessário saber a magnitude do fluxo, mas apenas o valor da terceira harmônica de tensão quando o motor opera na sua condição nominal. O método proposto é simples de ser implementado, computacionalmente leve e insensível aos parâmetros do motor. Esta última característica é especialmente atrativa, pois boa parte cios acionamentos elétricos propostos na literatura com controle escalar tem seu desempenho insatisfatório devido à influência da variação da resistência de estator, principalmente quando o motor opera em baixas velocidades. Resultados experimentais mostram que a técnica implementada tem um excelente desempenho em regime permanente, ainda que com carga mecânica, e bom desempenho nos transitórios / Abstract: In this work it is presented the implementation of scalar control V/f technique. It keeps the air gap flux constant in its rated value by the control of the relation between third harmonic voltage, due to saturation, and electric frequency. When the coils are conected in Y. the third harmonic is obtained by the sum of staler phase voltage. We propose that it is not necessary to know the air gap flux magnitude, but only the third harmonic value when the induction motor operates in rated condition. The proposed method is easy to implement, has a light coputational processing and it is not sensitive to motor parameters. This last caracteristic is attractive, because many electric drivers have low performance due to the influence of stator resistence variation, mainly when, the motor operates in reduced speed. Experimental results show the high performance of system in steady state, with applied load, and good performance in dynamic situation / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

This diploma thesis deals with the design of the asynchronous mathematical model, and creation its model in MATLAB Simulink. And by creating different types of asynchronous motor control. At the beginning of the work there are theoretical knowledge about transformation of quantities into coordinates, which are needed for creation of mathematical model and further for machine control. Furthermore, control logarithms are created from these transformed quantities, which can be used to control the torque or engine speed. It is a constant magnetic flux control, scalar control, vector control, and ultimately direct torque control. All derived control algorithms have been tested in MATLAB Simulink. Where were simulations of investigated quantities.

The diploma thesis deals with the simulation of induction motor control with respect to high efficiency. The theory of an induction motor is described here, with emphasis on its losses. Scalar and vector control are also described here. Vector control is optimized for higher efficiency. Subsequently, the creation of a model in the program đť‘€đť´đť‘‡ đťżđť´đťµâ’𝑆𝑖𝑚𝑢𝑙𝑖𝑛𝑠is described here, for the comparison of scalar and vector control with optimization.

The diploma thesis deals with the simulation of induction motor control with respect to high efficiency. The theory of an induction motor is described here, with emphasis on its losses. Scalar and vector control are also described here. Vector control is optimized for higher efficiency. Subsequently, the creation of a model in the program MATLAB - Simulink is described here, for the comparison of vector control with and without optimization.

Baigiamojo magistro darbo tiriamasis objektas – intelektinė tiesiaeigė elektros pavara. Tyrimo tikslas – ištirti tiesiaeigę elektros pavarą, valdoma neraiškiuoju reguliatoriumi. Uždaviniai – sudaryti intelektinės tiesiaeigės pavaros kompiuterinį modelį gauti ir ištirti imitacijos rezultatus, juos palyginti su tokia pačia PI reguliatoriumi valdoma pavara. Literatūros analizės dalyje išnagrinėtas neraiškiosios logikos panaudojimas valdant elektros pavaras. Pateikiami straipsniai, kuriose aprašomos elektros pavarų valdymo galimybės panaudojant neraiškiosios logikos reguliatorius. Teorinėje dalyje išnagrinėjamos tiesiaeigės pavaros, pateikiamos jų taikymo apžvalga ir panaudojimo galimybės. Taip pat išanalizuojamos neraiškiosios valdymo sistemos, jų sudarymo principai ir panaudojimas reguliatoriuose. Aptariami tiesiaeigių elektros pavarų valdymo būdai. Tiriamojoje dalyje sukurtas tiesiaeigės pavaros kompiuterinis modelis, suprojektuotas neraiškusis reguliatorius, gauti imitacijos rezultatai. Rezultatams palyginti sudarytas pavaros modelis naudojant PI reguliatorių. Gauti rezultatai ištirti ir palyginti. Išnagrinėjus tiesiaeigės asinchroninės pavaros imitavimo rezultatus pateikiamos išvados ir pasiūlymai. Darbą sudaro 7-ios dalys: įvadas, literatūros analizė, tyrimo tikslas ir uždaviniai, teorinė dalis, tiriamoji dalis, apibendrinančioji dalis, naudotos literatūros šaltinių sąrašas. Darbo apimtis – 65 psl. teksto be priedų, 43 iliustr., 2 lent., 37 bibliografiniai šaltiniai, iš jų... [toliau žr. visą tekstą] / Research subject of master thesis is intelligent linear electric drive. Objective of the study - to investigate linear electric actuator, controlled with Fuzzy controller. Tasks - create computer model of intellectual linear drive, to investigate the simulation results and compare them with the same drive which controlled with PI controller. In the literary analysis part usage of Fuzzy logic in the electric drives control has been examined. Articles with description of the electric drive control features using Fuzzy logic controller have been given. In the theoretical part the linear actuators are analyzed, the review of the application and their usability was given. Also are analyzed Fuzzy control systems, their creation principles and usage in the regulators. The linear electric drive control methods are discussed. In the research part computer model of the linear drive has developed, designed Fuzzy controller, analyzed simulation results. For results comparing the model with PI controller has designed. The results obtained are examined and compared. After examination results of the linear induction drive simulation the conclusions and recommendations are given. The work consists of seven parts: introduction, literature review, the study aims and objectives, the theoretical part, research, generalization and used references. Thesis volume - 65 pages text without appendixes, 43 pictures, 2 tables, 37 bibliographical sources, including internet links 10. Appendixes are... [to full text]

L’optimisation de l’efficacité énergétique des machines électriques constitue un domaine de recherche bien développé et fait partie des objectifs de plusieurs accords internationaux comme le projet Energie-Climat de la Commission Européenne visant l’amélioration de 20% d’efficacité pour 2020, encore étendu pour 2030 avec des objectifs plus importants. Ainsi, cette thèse propose un procédé d’optimisation du rendement du moteur asynchrone en agissant sur les paramètres du contrôle. Pour atteindre cet objectif, le flux dans l’entrefer est adapté selon un tableau de flux optimal calculé hors ligne pour tous les points de fonctionnement possibles. Ce flux est déterminé avec le plus haut degré de précision possible en se basant sur un modèle dynamique de la machine développé dans ces travaux. Ce dernier pallie le point faible du modèle dynamique classique, en prenant en compte l’effet des pertes fer. Le modèle des pertes fer utilisé est celui de Bertotti, qui les évalue en fonction de la fréquence et de l’amplitude du champ magnétique. Les pertes sont alors représentées par une résistance variable, continuellement évaluée selon le point de fonctionnement. Le tableau de flux optimal obtenu est fonction des conditions d’opération repérées dans le plan couple-vitesse. Ainsi l’étude montre que le flux peut être optimisé pour des valeurs de couple sensiblement inférieures à environ la moitié du couple nominal, ce seuil variant en fonction de la vitesse. La méthode d’optimisation proposée est simulée puis testée pour le contrôle scalaire et le contrôle vectoriel indirect par orientation de flux rotorique, afin de montrer la généricité de l’approche. La validation est conduite sur une maquette expérimentale d’une puissance de 5.5 kW et pour 2 machines asynchrones de générations différentes (IE2 et IE3). Les résultats obtenus montrent la réduction des pertes dans la machine et donc une amélioration du rendement global, tout en préservant un comportement dynamique satisfaisant. L’optimisation de l’efficacité énergétique est ainsi validée pour les deux structures de contrôle et pour les deux types de machine. Outre une comparaison avec la simulation, la solution proposée est comparée aux méthodes existantes afin d’en apprécier l’efficacité. / Energy efficiency optimization of electric machines is an important research field and is part of the objectives of several international projects such as the European Commission Climate and Energy package which has set itself a 20% energy savings target by 2020, and was extended for 2030 with higher targets. Therefore, this thesis proposes an efficiency optimization method of the Induction Machine (IM) through the variation of the control parameters. To achieve this goal, the flux in the airgap is modified according to an optimal flux table computed off-line for all possible operating points. The flux table is calculated with the best possible accuracy through an improved dynamic model of the IM, developed in these works. The latter avoids the main drawback of the classic dynamic model, by considering the effect of core losses. The core loss model established by Bertotti is used. It depends on the frequency and the amplitude of the magnetic field. The losses are then represented by a variable resistor, continuously evaluated according to the operating point. The established optimal flux table is a function of the operating conditions in terms of torque and speed. Indeed, the results show that the flux can be optimized for torque values less than about half the rated torque, and that this threshold is influenced by the speed. The proposed optimization method is simulated, then tested for the scalar control and the field-oriented control, in order to show the genericity of the proposed approach. The validation is carried on an experimental test bench for two 5.5 kW induction motors of different efficiency standards (IE2 and IE3). The results obtained show the reduction of the losses in the motor, thus an improvement of the overall efficiency while preserving a satisfactory dynamic behavior. Consequently, the optimization of the energy efficiency is validated for the two control structures and for the two studied motors. In addition to the validation of the simulation results, the proposed approach is compared to existing methods to assess its effectiveness

The goal of this master´s thesis is primarily the theoretical analysis of three-phase inverters and subsequent familiarization of the reader with their detailed practical structure. The first part is devoted to the general definition of the power semiconductor converter as such. The following part describes the principle of three-phase pulse width modulation including the widely used principle of scalar control of induction motors. The second half of the thesis is already focused on the practical design of a three-phase inverter for a 50 kW high-speed induction motor. This section explains the problem of sizing and selecting all of the sub-elements of the inverter based on the parameters specified by the end user of the device.