Made available in DSpace on 2014-12-17T14:56:13Z (GMT). No. of bitstreams: 1 FlavioGD_DISSERT.pdf: 434327 bytes, checksum: 80a9ab9e6651a6af8ae71caa0fd3bfec (MD5) Previous issue date: 2011-09-09 / This paper describes the study, computer simulation and feasibility of implementation of vector control speed of an induction motor using for this purpose the Extended Kalman Filter as an estimator of rotor flux. The motivation for such work is the use of a control system that requires no sensors on the machine shaft, thus providing a considerable cost reduction of drives and their maintenance, increased reliability, robustness and noise immunity as compared to control systems with conventional sensors / Esta disserta??o apresenta o desenvolvimento de uma simula??o computacional com a finalidade de demonstrar o funcionamento do controle vetorial para velocidade de um motor de indu??o trif?sico utilizando m?todo de estima??o pelo Filtro de Kalman Estendido, bem como os procedimentos necess?rios para sua implementa??o pr?tica. A motiva??o maior que influenciou a pesquisa est? na utiliza??o de um sistema de controle inovador que n?o necessita de sensores no eixo da m?quina (t?cnica sensorless), proporcionando desta forma uma consider?vel redu??o nos custos de acionamentos e manuten??o, aumento da confiabilidade, da robustez e da imunidade a ru?dos em rela??o ao controle de motores convencionais com sensores

This paper proposes the position control of an articulated manipulator of two degrees of freedom driven by induction motors with a controller in the current loop. The work includes the mechanical modeling of the handler that will be developed from the direct and inverse kinematics and position control of induction motors operating system and uncoupled allocated in the manipulator. Thus, we developed two strategies for control of manipulators with two degrees of freedom, one using the scheme for field-oriented vector control and other means of indirect sliding mode control (Sliding-Mode Control - SMC). These control strategies are applied to current loop of induction motors that drive the manipulator. The parameters of the position controller of manipulator are taken into account in calculating the controller parameters of the current control loop, in order to obtain satisfactory results in the positioning the degrees of freedom. In addition, we performed a comparative study between the indirect field-oriented vector control and sliding mode control applied to the current loop. The advantage of the SMC compared to the indirect field-oriented vector control due to the first had in its control law, developed in this thesis, the use of position degree of freedom manipulator applied directly in the control law, while the second acted only as a disturbed rejection controller for the position loop. The Proportional-Integral (PI) was used in the position and speed loops for both current control algorithms to provide a standard for comparison between. For the purpose of implementing the control system individually for each engine and motors coupled to the manipulator used a digital signal processor. / O presente trabalho propÃe o controle de posiÃÃo de um manipulador articulado de dois graus de liberdade acionado a partir de motores de induÃÃo trifÃsicos com um controlador na malha de corrente. O trabalho contempla a modelagem mecÃnica do manipulador que serà desenvolvida a partir das cinemÃticas direta e inversa e o controle de posiÃÃo dos motores de induÃÃo atuando desacoplados do sistema e alocados no manipulador. Deste modo, foram desenvolvidas duas estratÃgias de controle de manipuladores com dois graus de liberdade, uma utilizando o esquema por controle vetorial de campo orientado indireto e outra atravÃs de controle por modos deslizantes (Sliding Mode Control â SMC). Estas estratÃgias de controle sÃo aplicadas a malha de corrente dos motores de induÃÃo que acionam o manipulador. Os parÃmetros do controlador de posiÃÃo dos manipuladores sÃo levados em consideraÃÃo no cÃlculo dos parÃmetros do controlador da malha de controle de corrente, de modo a se obter resultados satisfatÃrios no posicionamento dos graus de liberdade. AlÃm disso, foi realizado um estudo comparativo entre o controle vetorial de campo orientado indireto e o controle de modos deslizantes aplicado na malha de corrente. A vantagem do SMC em relaÃÃo ao controle vetorial de campo orientado indireto deveu-se a que o primeiro possuÃa em sua lei de controle desenvolvida nesta tese a utilizaÃÃo direta da posiÃÃo do grau de liberdade do manipulador, enquanto que o segundo atuava somente como um controlador com rejeiÃÃo ao distÃrbio. O controlador Proporcional-Integral (PI) foi utilizado nas malhas de posiÃÃo e velocidade de modo a fornecer um padrÃo de comparaÃÃo confiÃvel entre os controladores de corrente. Com a finalidade de implementar o sistema de controle de cada motor individualmente e dos motores acoplados ao manipulador utilizou-se um processador digital de sinais.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Ecology studies of Aedes aegypti are crucial to understand the behavior and adaptations made by the species according to their environment and that became evident during the evolutionary process due to different selective pressures facing the species in their origin environment. Therefore this study aimed to evaluate aspects of vectorial capacity and resistance to organophosphate temephos for Ae. aegypti from different regions of Sergipe. In addition to the resistance ratio of the populations to larvicides, developmental parameters and reproductive outcomes were duration of theimmature, number of pupae formed and adults emerged, sex ratio, survival of adults in different feeding conditions, fecundity of females, fertility eggs under stress climate, amount of blood ingested, the size of specimens and the occurrence of asymmetric wing. All evaluated populations of Ae. aegypti were resistance to temephos . The population from Neopolis, a city with favorable climatic characteristics for the development of species, showed a smaller ratio of the larvicide resistênicia and performance of developmental and reproductive variables evaluated. The population from Pinhão, which comes from the semi-arid, and has the highest resistance ratio to temephos, including outlier compared to those presented by other people, which was also exhibited greater loss in the parameters of vectorial capacity, with the exception of variable viability of eggs in a condition of environmental stress, for which the best performance. Thus, changes were observed in parameters of vectorial capacity which now seemed to be related to the climatic conditions of the original environment of the populations, probably due to adaptations developed by individuals, sometimes were related to the differents status of resistance to temephos observed. / Estudos da ecologia de populações de Aedes aegypti são fundamentais para se conhecer o comportamento e as adaptações apresentadas pela espécie de acordo com o ambiente em que vivem e que se evidenciaram durante o processo evolutivo em função das diferentes pressões seletivas que as espécies enfrentam em seu ambiente de origem. Assim, este estudo teve como objetivo avaliar aspectos da capacidade vetorial e a resistência ao organofosforado temephós de populações de Ae. aegypti provenientes de diferentes regiões do estado de Sergipe. Além da razão de resistência das populações ao larvicida, os parâmetros de desenvolvimento e reprodutivos observados foram duração do período imaturo, quantidade de pupas formadas e de adultos que emergiram, razão sexual, sobrevivência dos adultos em diferentes condições de alimentação, fecundidade das fêmeas, fertilidade dos ovos sob estressse climático, quantidade de sangue ingerido, tamanho dos espécimes e ocorrência de assimetria alar. Todas as populações de Ae. aegypti avaliadas apresentaram resistência ao temephós. A população proveniente de Neópolis, município com características climáticas favoráveis ao desenvolvimento da espécie, apresentou uma das menores razão de resistênicia ao larvicida e melhor desempenho das variáveis de desenvolvimento e reprodução avaliadas. Já a população de Pinhão, originária da região do semi-árido, além de apresentar a maior razão de resistência ao temephós, inclusive com valor discrepante em relação aos apresentados pelas demais populações, também foi a que exibiu maior perda nos parâmetros da capacidade vetorial, com exceção da variável viabilidade dos ovos em condição de estresse climático, para a qual apresentou o melhor desempenho. Assim, foram observadas variações em parâmetros da capacidade vetorial que ora pareciam estar relacionadas às condições climáticas do ambiente de origem das populações, provavelmente em virtude das adaptações desenvolvidas pelos indivíduos, ora relacionavam-se com os diferentes status de resistência ao temephós observados.

Orientador: Edson Bim / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T08:39:36Z (GMT). No. of bitstreams: 1 SguareziFilho_AlfeuJoaozinho_M.pdf: 4747025 bytes, checksum: 077f211f88c422646414f234628ad798 (MD5) Previous issue date: 2007 / Resumo: Este trabalho visa o estudo de métodos de projeto de controladores mediante o emprego da função de transferência complexa; o controle em baixas velocidades de um motor de indução trifásico orientado no fluxo do rotor, bem como no do estator, é o objetivo a ser alcançado. A formulação do modelo vetorial do motor de indução com emprego da função de transferência complexa e do controle vetorial são apresentados. Para validar a proposta, um controlador de ganho proporcional complexo é realizado. Resultados de simulação e de experimentos são obtidos / Abstract: This work aims the study of tunning methods for controllers on vector control using the complex transfer function; low speed control by using the rotor or stator flux orientation on the induction motor is the objetctive. The complex transfer function formulation, its aplication on induction machine model and vector control are presented. To validate the proposal, a proportional complex gains is proposed. Simulation and experimentally results are presented. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientadores: Ernesto Ruppert Filho, Marcelo Gradella Villalva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T14:53:53Z (GMT). No. of bitstreams: 1 Espindola_MarcosFernando_M.pdf: 5114547 bytes, checksum: 1601ee84cd6d17c671ba644a288c398d (MD5) Previous issue date: 2012 / Resumo: Apresenta-se a implementação de um inversor trifásico de tensão a três níveis para ser utilizado no controle de velocidade de um motor síncrono trifásico a imãs permanentes usando o método de controle vetorial. Realizou-se o estudo, projeto e construção de um inversor de tensão a três níveis com neutro grampeado ou inversor NPC neutral point clamped. Utilizou-se modulação em largura de pulsos por vetores espaciais no controle vetorial de velocidade do motor. Foram realizadas simulações do sistema proposto usando os aplicativos computacionais Matlab/Simulink e PSIM. Realizou-se em seguida uma montagem experimental constituída de um motor síncrono a imãs permanentes de 0,75 kW acoplado a um freio eletromagnético que lhe serviu de carga mecânica. O sistema motor e carga foi acionado pelo inversor com modulação em largura de pulsos por vetores espaciais e os resultados obtidos do controle de velocidade realizado, incluindo reversão de velocidade e frenação do motor, são apresentados no trabalho. Comparou-se também o desempenho de um inversor a três níveis usando modulação em largura de pulsos por vetores espaciais com o desempenho de um inversor a dois níveis usando modulação em largura de pulsos por vetores espaciais na alimentação de uma carga resistiva. Resultados de simulação e resultados experimentais são apresentados. Neste trabalho realizou-se uma comparação qualitativa entre o uso do inversor a dois níveis e do inversor a três níveis que mostra em que situações é conveniente utilizar o inversor a três níveis / Abstract: It is presented the implementation of a three phase three level voltage inverter to be used in the speed control of a three phase permanent magnet synchronous motor using the vector control method. To achieve this goal, it was carried out the study, design and construction of a three level neutral point clamped voltage inverter or NPC inverter. For the control of the motor it was used a space vector modulation. The proposed system was simulated using Matlab/Simulink and PSIM softwares. It was carried out an experimental assembly consisting of a 0.75 kW permanent magnet synchronous motor coupled to an electromagnetic brake as a mechanical load. The motor and load system were triggered by the inverter with space vector modulation. The results of the speed control, including reversal of speed and motor breaking, are presented in the study. The performance of a three level inverter using space vector modulation is compared to the performance of a two level inverter using space vector modulation feeding a resistive load. The simulation and experimental results are presented. In this work a qualitative comparison between the two level inverter and three level inverter was done showing in wich situations it is better to use the three level inverter / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

At present, one of the main issues in electric power networks is the reduction in conventional generation and its replacement by low inertia renewable energy generation. The balance between generation and demand has a direct impact on the system frequency and system inertia limits the frequency rate of change until compensation action can be undertaken. Traditionally generation managed frequency. In future, loads may be required to do more than just be able to be switched off during severe under frequency events. This thesis focuses on the development and practical implementation of the control structure of a smart adaptive load for network power-frequency support applications. The control structure developed makes use of advanced demand side management of fan loads (powered by AC drives) used in heating, ventilation, and air conditioning systems; where a change in power at rated load has little effect on their speed due to the cubic relationship between speed and power. The AC drive implemented in this thesis is based on an induction motor and a two level voltage source converter. To achieve the smart adaptive load functionality, first a power-frequency multi-slope droop control structure (feedforward control) is developed; relating the frequency limits imposed by the network supplier and the fan power-speed profile (Chapter 2, Fig 2.19). Secondly, this control structure is combined with the control developed, in Chapter 3, for the AC drive powering the fan load. The full development of the control structure of the AC drive, its tuning process and its practical implementation is given; an equation is developed to find suitable tuning parameters for the speed control of the nonlinear load (fan load), i.e. Eq. (3.59).The analysis and simulation results provided in Chapter 4 conclude that a fast control of the active power drawn by the AC drive is possible by controlling the electromagnetic torque (hence current) of the induction motor without disturbing the fan load overly. To achieve this, changes between closed loop speed control and open loop torque control (power control) are performed when needed. Two main issues were addressed before the hardware implementation of the smart adaptive load: the estimation of the network frequency under distorted voltage conditions, and the recovery period of the network frequency. In this thesis two slew rate limiters were implemented to deal with such situations. Other possible solutions are also outlined. Finally, experimental results in Chapter 5 support results given in Chapter 4. A full power-frequency response is achieved by the smart adaptive load within 3s.

>Magister Scientiae - MSc / Tsetse flies (Glossina spp) are vectors of African trypanosome (Trypanosoma spp) parasites, causative agents of Human African trypanosomiasis (sleeping sickness) and Nagana in livestock. Research suggests that tsetse fly immunity factors are key determinants in the success and failure of infection and the maturation process of parasites. An analysis of tsetse fly immunity factors is limited by the paucity of genomic data for Glossina spp. Nevertheless, completely sequenced and assembled genomes of Drosophila melanogaster, Anopheles gambiae and Aedes aegypti provide an opportunity to characterize protein families in species such as Glossina by using a comparative genomics approach. In this study we characterize thioester-containing proteins (TEPs), a sub-family of immunity-related proteins, in Glossina by leveraging the EST data for G.morsitans and the genomic resources of D. melanogaster, A. gambiae as well as A.aegypti.A total of 17 TEPs corresponding to Drosophila (four TEPs), Anopheles (eleven TEPs) and Aedes aegypti (two TEPs) were collected from published data supplemented with Genbank searches. In the absence of genome data for G. morsitans, 124 000 G.morsitans ESTs were clustered and assembled into 18 413 transcripts (contigs and singletons). Five Glossina contigs (Gmcn1115, Gmcn1116, Gmcn2398, Gmcn2281 and Gmcn4297) were identified as putative TEPs by BLAST searches. Phylogenetic analyses were conducted to determine the relationship of collected TEP proteins.Gmcn1115 clustered with DmtepI and DmtepII while Gmcn2398 is placed in a separate branch, suggesting that it is specific to G. morsitans.The TEPs are highly conserved within D. melanogaster as reflected in the conservation of the thioester domain, while only two and one TEPs in A. gambiae and A. aegypti thioester domain show conservation of the thioester domain suggesting that these proteins are subjected to high levels of selection. Despite the absence of a sequenced genome for G. morsitans, at least two putative TEPs where identified from EST data.

No description available.

Variable-speed Induction motor drives are nowadays used for various kinds of industrial processes, transportation systems, wind turbines and household appliances in the world. The majority of drives are for general purpose speed control applications where accurate speed control is not required for entire speed range. But for high dynamic drive application, very precise and fast control of induction motor drive is essential. For such applications, sophisticated and well-performing control design is a key issue. Precise and accurate torque control of the Induction Motor (IM) can only be accomplished by vector control and direct torque control. In terms of space vector theory, vector control implies that the instantaneous torque is controlled by way of the stator current vector that is orthogonal to the rotor flux vector. Precise knowledge of the rotor flux angle is therefore essential for a vector controlled IM. IMs do not allow the flux position to be easily measured, so most modern vector controlled IM drives rely on flux estimation. This means that the flux angle is derived from a flux estimator, using the dynamic model of the IM. Given that the rotor speed of the IM is measured by a mechanical shaft sensor. Flux estimation is a fairly easy task. However, vector control of IM without mechanical shaft speed sensor is of current interest in industrial environment. The driving motivations behind the development in sensorless control are lower cost, improved reliability and operating environment. In this thesis, a sensorless vector control scheme for rotor flux estimation using current error space phasor based hysteresis controller is proposed including the method for estimation of leakage inductance, Ls. For frequencies of operation less than 25 Hz, the rotor voltage and hence the rotor flux position is computed during the inverter zero voltage space vector using steady state model of IM. For above 25 Hz, active vector period and steady state model of IM is used. The whole rotor flux estimation scheme is dependent on current error space phasor and the steady state motor model, with rotor flux as a reference vector. Since no terminal voltage sensing is involved, dead time effects will not create problem in rotor flux sensing at low frequencies of operation. But appropriate device on-state drop are compensated at low frequencies (below 5 Hz) of operation to achieve a steady state operation up to less than 1 Hz. A constant switching frequency hysteresis current controller is used in inner current control loop for the PWM regulation, with smooth transition of operation to six-step mode operation. A simple Ls estimation based on current error space phasor is also proposed to nullify the deteriorating effect on rotor flux estimation. The parameter sensitivity of the control scheme to changes in the stator resistance Rs is also investigated. The drive scheme is tested up to a low frequency operation less than 1 Hz. The extensive simulation and experiment results are presented to show the proposed scheme’s good dynamic performance extending up to six-step operation. In contrast to vector control, direct torque control (DTC) method requires the knowledge of stator resistance only and thereby decreasing the associated sensitivity to parameters variation and the elimination of speed information. DTC as compared to vector control does not require co-ordinate transformation and PI controller. DTC is easy to implement because it needs only two hysteresis comparators and a lookup table for both flux and torque control. This thesis also investigates the possibilities in improvement of direct torque control scheme for high performance induction motor drive applications. Here, two schemes are proposed based on the direct torque control scheme for IM drive using 12-sided polygonal voltage space vectors for fast torque control. The torque control scheme based on DTC algorithm is proposed using 12-sided polygonal voltage space vector. The basic DTC scheme is used to control the torque. But the IM drive is open-end type. For torque control, the voltage space vectors orthogonal to stator flux vector in 12-sided polygonal space vector structure are used as hexagonal space vector based DTC scheme. The advantages achieved due to 12-sided polygonal space vector are mainly fast torque control and small torque ripple. The fast transient of torque with precise control is achieved using voltage space vector placed with a resolution of ±15. The torque ripple will be less as 6n±1 (n=odd) harmonic torque is totally eliminated from the whole range of PWM modulation. The comparative analysis of proposed 12-sided polygonal voltage space vector based DTC and conventional hexagonal space vector based DTC is also presented. Extensive simulation and experiment results are also presented to show the fast torque control at speeds of operation ranging from 5 Hz to the rated speed. The concept of 12-sided polygonal space vector based DTC is further extended for a variable speed control scheme using estimated fundamental stator voltage for sector identification. The conventional DTC scheme uses stator flux vector for identification of the sector and the switching vector are selected based on this sector information to control stator flux and torque. However, the proposed DTC scheme selects switching vectors based on the sector information of the estimated fundamental stator voltage vector and its relative position with respect to the stator flux vector. The fundamental stator voltage estimation is based on the steady state model of IM and information of synchronous frequency which is derived from computed stator flux using a low pass filter technique. The proposed DTC scheme utilizes the exact position of fundamental stator voltage vector and stator flux vector position to select optimal switching vector for fast control of torque with small variation of stator flux within hysteresis band. The present DTC scheme allows the full load torque control with fast transient response to very low speeds of operation below 5 Hz. The extensive simulation and experiment results are presented to show the fast torque control for speed of operation from zero speed to rated speed. However, the present scheme will have all the advantages of DTC scheme using stator flux vector for sector identification. All the above propositions are first simulated by MATLAB/Simulink and subsequently verified by an experimental laboratory prototype. The proposed control schemes are experimentally verified on a 3.7 kW IM drive. The control algorithms of the sensorless vector control using current error space phasor as well as DTC using 12-sided polygonal voltage space vector are completely implemented on a TI TMS320LF2812 DSP controller platform. These are some of the constituents for chapters 2, 3 and 4 in this thesis. Additionally, the first chapter also covers a brief survey on some of the recent progresses made in the field of sensorless vector control, direct torque control and current hysteresis controller. The thesis concludes with suggestion for further exploration.

This thesis is focused on simulation of laboratory stand located on University of technology in Brno which is containing DC and asynchronous motor. This thesis includes mathematical model of DC motor, regulator of current, regulator of speed and DC convertor. It also contains model of asynchronous squirrel cage motor and models for scalar and vector control. Whole simulation is calculated in Simulink which is part of program Matlab.