In response to the global climate change and environmental protection needs, more and more nations take renewable energies as one of the major future energy policies for its characteristics of clean, low greenhouse gas emission and self-productivity. Among Taiwan¡¦s many renewable energy development, wind energy is always on the list. Wind energy will not only avoid the problems of carbon dioxide which cause greenhouse effect, but also refrain pollution caused by fossil fuel or nuclear energy. The induction generator is a fundamental component of a wind machine. It¡¦s electric port and control can be classified into single fed control and double fed control. Through various comparisons of control and operation, double fed control seems to be more stable at present. Double fed induction generator may continuously produce power at island state without the supply of reactive power from parallel capacitor or the synchronous generator. which is the biggest advantage than single fed induction. , In other words, double fed induction generator may supply power independently. The induction generator is a time-varying and non-linear component. So the traditional rule of scalar control is not adopted in the thesis. The induction generator can be linearized by using vector control, and the power flow can also be directed with the control of its composition of rotor current vector and the controller is designed under the above methodology. The thesis aims to simulate, analyze and compare the steady and transient states of single fed and double fed wind generators with the purposes a more through understanding of the controller and its operation.

Thesis (Ph.D.)--York University, 2006. Graduate Programme in Mathematics and Statistics. / Typescript. Includes bibliographical references (leaves 126-132). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19847

Thesis (M.P.H.)--University of Michigan, 1944.

Thesis (M.P.H.)--University of Michigan, 1944.

Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη και την υλοποίηση του διανυσματικού ελέγχου ενός τριφασικού ασύγχρονου κινητήρα. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σκοπός μας είναι η μελέτη, η επιλογή και τελικά η υλοποίηση ενός συγκεκριμένου είδους διανυσματικού ελέγχου ασύγχρονου τριφασικού κινητήρα μέσω της χρήσης ψηφιακού μικροελεγκτή . Αρχικά, γίνεται μια αναφορά στα κινητήρια συστήματα και στην σημασία των ασύγχρονων κινητήρων σε ένα ηλεκτρικό κινητήριο σύστημα καθώς και στον έλεγχο αυτών και δη το διανυσματικό. Στη συνέχεια, μελετώνται η βασική αρχή λειτουργίας, οι μαθηματικές εξισώσεις, τα μοντέλα λειτουργίας καθώς και τα κατασκευαστικά χαρακτηριστικά των ασύγχρονων μηχανών αλλά και της μηχανής που χρησιμοποιήθηκε στην πειραματική μας διάταξη. Στο επόμενο βήμα, γίνεται μια πολύ σύντομη ιστορική αναδρομή στην ανάπτυξη του διανυσματικού ελέγχου , εισαγωγή και θεωρητική ανάλυση σε βάθος των αρχών αυτού και αναλυτική παρουσίαση όλων των ειδών του. Τέλος, καταλήγουμε στην επιλογή της μεθόδου που θα χρησιμοποιήσουμε. Συνεχίζοντας, κάνουμε μια εισαγωγή στους ηλεκτρονικούς μετατροπείς ισχύος και αναλύουμε τον τριφασικό αντιστροφέα τάσης που χρησιμοποιήθηκε στην παρούσα διπλωματική εργασία. Επόμενο βήμα είναι η παρουσίαση και η περιγραφή του μικροεπεξεργαστή dsPIC30F4011 της εταιρίας Microchip ενώ περιγράφεται αναλυτικά και η διαδικασία ανάπτυξης του προγράμματος για την υλοποίηση του διανυσματικού ελέγχου. Τέλος, παρατίθενται οι κυματομορφές που προέκυψαν από τα πειράματα που διενεργήθηκαν μετά την ολοκλήρωση του προγράμματος και του ελέγχου του. / This diploma thesis addresses the design and implementation of vector control of a three-phase asynchronous motor. The project was based at the Laboratory of Electromechanical Energy Conversion, Department of Electrical and Computer Engineering School of Engineering, University of Patras. Our objective is the study, the choice and ultimately the implement of a specific type of vector controlfor a three-phase asynchronous motor using digital microcontroller. Initially, there is a reference to the electric drive systems and to the importance of an asynchronous motor in an electric drive system and to its control, especially the vector control. Following there is a theoretical analysis of the basic principle of operation,the mathematical equations, the models of operation and the construction of an asynchronous machine. The next step is a very brief historical reference to the development of vector control.There is also a theoretical analysis of the principles of this and detailed presentation of all the species. Finally, we conclude to the method we used. Our next step is to present the electronic power converters and to analyze the three-phase inverter which was used in this diploma thesis. Following, there is a presentation and description of the microprocessor dsPIC30F4011(Microchip).Just after that,we describe the process of program development for the implementation of vector control in a detailed analysis . Finally, we present the waveforms coming up from the experiments that we carried out after the completion of the process of vector control.

Made available in DSpace on 2015-03-03T11:52:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-28Bitstream added on 2015-03-03T12:06:09Z : No. of bitstreams: 1 000810574_20160728.pdf: 555774 bytes, checksum: a1eafb543fd960c6eb728f54e4d8d4fa (MD5) Bitstreams deleted on 2016-07-29T12:53:57Z: 000810574_20160728.pdf,. Added 1 bitstream(s) on 2016-07-29T12:54:50Z : No. of bitstreams: 1 000810574.pdf: 619509 bytes, checksum: 02da17d2039311135a8a7eb0b12e2091 (MD5) / A dengue, doença infecciosa aguda, causada por um vírus da família Flaviviridae e transmitida aos humanos pela picada dos mosquitos do gênero Aedes, é considerada um dos principais problemas de saúde pública no mundo. O Aedes aegypti é o único vetor conhecido nas Américas e no Brasil está presente nos 26 estados e no distrito federal. A indisponibilidade de uma vacina que imunize a população contra os quatro sorotipos da dengue restringe a prevenção da doença ao controle do vetor. Isto é feito por aplicações de inseticidas químicos, porém o uso frequente em altas doses tem selecionado populações resistentes do mosquito. Diante dessa situação há necessidade de se buscar produtos alternativos que tenham efeito nestas populações. Diversos estudos demonstraram que os óleos essenciais de Syzygium aromaticum e Citrus sinensis apresentam pronunciada atividade larvicida, assim, este trabalho teve por objetivo avaliar o potencial destes produtos como alternativa de controle larvicida para populações de A. aegypti resistentes ao organofosforado temephos e verificar o efeito da associação deste inseticida aos óleos essenciais sobre a atividade larvicida. Avaliou-se também, a influência dos óleos essenciais na oviposição do vetor quando presentes nos sítios de postura. A comparação da atividade larvicida nas populações resistentes e suscetíveis foi realizada por meio das concentrações letais obtidas em ensaios de dose-resposta, seguindo metodologia proposta pela Organização Mundial da Saúde. Para avaliar o efeito da associação dos óleos essenciais ao temephos comparou-se a atividade larvicida das associações com a do temephos e o efeito no comportamento de oviposição foi avaliado pela comparação do número de ovos colocados nos sítios de postura, contendo soluções dos óleos essenciais em relação aos contendo somente água. Os resultados revelaram que os óleos essenciais exerceram atividade ... / Dengue fever an acute infectious disease caused by Flaviviridae family virus, transmitted to humans by the mosquitoes bite of Aedes genus. It is considered one of the most public health problems in the world. The Aedes aegypti is the only known vector in the Americas and in Brazil is present in 26 states and the federal district. The unavailability of a vaccine to immunize people against the four dengue serotypes restricted the disease prevention to the vector control. The control is done by chemical insecticides application, but the frequent use in high doses, have selected resistant mosquito populations. In front of this situation, it is necessary to seek for alternative products that have effect on these populations. Several studies demonstrated that Syzygium aromaticum and Citrus sinensis essential oils have larvicidal activity, so the aim of this study was to evaluate the potential of the essencial oils as an alternative to control A. aegypti larvae resistant to the organophosphate temephos and analyze the effect of this insecticide and essencial oils association on the larvicidal activity. It was evaluated too the influence of essencial oils on vector oviposition, when present on the posture sites. The larvicidal activity was assessed by dose-response tests, according to the methodology proposed by the World Health Organization. To evaluate the effect of essential oils associatiate with temephos, the larvicidal associations activity was compared with the temephos. The effect on oviposition behavior was evaluated comparing the number of eggs in laying sites containing essential oils in relation to the number of eggs in laying sites containing only water. The results demonstrated that essential oils had larvicidal activity in resistant and susceptible to temephos populations, being an alternative to resistance management. The association of temephos and essential oils had an antagonist ...

Orientador: João Tadeu Ribeiro Paes / Banca: Maria de Lourdes da Graça Macoris / Banca: Francisco Anaruma Filho / Resumo: A dengue, doença infecciosa aguda, causada por um vírus da família Flaviviridae e transmitida aos humanos pela picada dos mosquitos do gênero Aedes, é considerada um dos principais problemas de saúde pública no mundo. O Aedes aegypti é o único vetor conhecido nas Américas e no Brasil está presente nos 26 estados e no distrito federal. A indisponibilidade de uma vacina que imunize a população contra os quatro sorotipos da dengue restringe a prevenção da doença ao controle do vetor. Isto é feito por aplicações de inseticidas químicos, porém o uso frequente em altas doses tem selecionado populações resistentes do mosquito. Diante dessa situação há necessidade de se buscar produtos alternativos que tenham efeito nestas populações. Diversos estudos demonstraram que os óleos essenciais de Syzygium aromaticum e Citrus sinensis apresentam pronunciada atividade larvicida, assim, este trabalho teve por objetivo avaliar o potencial destes produtos como alternativa de controle larvicida para populações de A. aegypti resistentes ao organofosforado temephos e verificar o efeito da associação deste inseticida aos óleos essenciais sobre a atividade larvicida. Avaliou-se também, a influência dos óleos essenciais na oviposição do vetor quando presentes nos sítios de postura. A comparação da atividade larvicida nas populações resistentes e suscetíveis foi realizada por meio das concentrações letais obtidas em ensaios de dose-resposta, seguindo metodologia proposta pela Organização Mundial da Saúde. Para avaliar o efeito da associação dos óleos essenciais ao temephos comparou-se a atividade larvicida das associações com a do temephos e o efeito no comportamento de oviposição foi avaliado pela comparação do número de ovos colocados nos sítios de postura, contendo soluções dos óleos essenciais em relação aos contendo somente água. Os resultados revelaram que os óleos essenciais exerceram atividade ... / Abstract: Dengue fever an acute infectious disease caused by Flaviviridae family virus, transmitted to humans by the mosquitoes bite of Aedes genus. It is considered one of the most public health problems in the world. The Aedes aegypti is the only known vector in the Americas and in Brazil is present in 26 states and the federal district. The unavailability of a vaccine to immunize people against the four dengue serotypes restricted the disease prevention to the vector control. The control is done by chemical insecticides application, but the frequent use in high doses, have selected resistant mosquito populations. In front of this situation, it is necessary to seek for alternative products that have effect on these populations. Several studies demonstrated that Syzygium aromaticum and Citrus sinensis essential oils have larvicidal activity, so the aim of this study was to evaluate the potential of the essencial oils as an alternative to control A. aegypti larvae resistant to the organophosphate temephos and analyze the effect of this insecticide and essencial oils association on the larvicidal activity. It was evaluated too the influence of essencial oils on vector oviposition, when present on the posture sites. The larvicidal activity was assessed by dose-response tests, according to the methodology proposed by the World Health Organization. To evaluate the effect of essential oils associatiate with temephos, the larvicidal associations activity was compared with the temephos. The effect on oviposition behavior was evaluated comparing the number of eggs in laying sites containing essential oils in relation to the number of eggs in laying sites containing only water. The results demonstrated that essential oils had larvicidal activity in resistant and susceptible to temephos populations, being an alternative to resistance management. The association of temephos and essential oils had an antagonist ... / Mestre

The research conducted at the department of Electrical Engineering of the University of South Florida campus in Tampa only covers the electrical aspect of electric drives. However, the performance of electric machinery is significantly impacted by temperature variation. The literature review shows three main control techniques in use today in electric drives namely, Scalar control, Direct Torque control and Field Oriented control. This thesis presents a temperature rise of rotor bars, stator winding, stator core and stator frame in a running three phase field-oriented controlled induction machine. A literature search shows that none of research has been carried out to investigate a thermal response of a field-oriented controlled induction motor. With this motivation, we were able to implement a lumped parameters thermal model of a three-phase field-oriented IM in MATLAB Simulink, which allows us to determine that rotor bars have the highest temperatures rising to 84 degrees Celsius. This confirms that rotors bars are the hottest part of a running IM as stipulated in literature.

Malaria is vectored by the mosquito Anopheles gambiae (Ag) in Sub-Saharan Africa and infects approximately 500 million people annually. The increasing prevalence of pyrethroid-resistant mosquitoes has amplified the need for development of new, selective mosquitocides for use on insecticide-treated nets. We have developed several phenyl-substituted N-methylcarbamates producing a high degree of selectivity for Anopheles gambiae acetylcholinesterase (AgAChE) over human AChE. Molecular models suggest alternate conformations (flexibility) of W84 and W431 (Ag numbering) at the hydrophobic subpocket of the AgAChE active site and poor flexibility within human AChE, allowing for the high selectivity of our novel carbamates. Initial selectivity data was obtained through screening of these insecticides while using ethanol as a solvent. Re-screening of these carbamates in the presence of 0.1% DMSO (v/v) resulted in antagonism of inhibition for AgAChE, thus reducing the AgAChE-selectivity by at least 10-fold. However, the presence of 0.1% DMSO did not antagonize the inhibition of human, Drosophila melanogaster, or Musca domestica AChE. Non-selective carbamates also displayed no solvent-dependent antagonism of inhibition in any species studied, including AgAChE. Molecular models provide an explanation for antagonism of inhibition when DMSO is present. I, and collaborators, propose that W84 and W431 in AgAChE comprise an allosteric pocket that is stabilized by DMSO and is responsible for the solvent-dependent antagonism of inhibition observed with AgAChE. / Master of Science in Life Sciences

Vector control technique is being widely used in ac motors drives for precise dynamic control of torque, speed and position. The application of vector control scheme to the induction motor drive and the complete modeling, analysis and simulation of the drive system are presented in this thesis. State space models of the motor and the speed controller and the real time models of the inverter switches and the vector controller are integrated to model the drive. Performance differences due to the use of PWM and hysteresis current controllers are examined. Simulation results of the torque and speed drive systems are given. The drive system is linearised around an operating point and the small signal response is evaluated. / Master of Science