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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Controle vetorial da máquina de indução por modos deslizantes integral utilizando método de anti-windup / Vector control of induction machine with integral sliding mode controller using anti-windup method

Carlos Matheus Rodrigues de Oliveira 17 March 2016 (has links)
Neste trabalho é proposto um estudo envolvendo o controle vetorial do Motor de Indução Trifásico, compreendendo o uso da teoria de modos deslizantes nas malhas de controle de fluxo e velocidade na estratégia de Controle Vetorial por Orientação Indireta de Campo (Indirect Field Oriented Control, IFOC), visando sobretudo, melhorar tanto o desempenho dinâmico quanto o problema de chattering. Para tanto, aborda-se o uso de uma função de chaveamento suave, analisando suas características perante o uso de diferentes superfícies de deslizamento. Com base nessas análises, tem-se a proposta de um controlador por modos deslizantes integral, englobando o uso de uma superfície de deslizamento integral em conjunto com um método de anti-windup, sendo tal método baseado em uma função triangular. Para verificar a atratividade às superfícies de fluxo e velocidade, é realizada uma investigação quanto ao uso de uma parcela paramétrica como ação de controle, dada pelo termo equivalente. Com o objetivo de analisar a topologia de controle proposta, resultados são obtidos por meio de simulação e de uma bancada experimental considerando diferentes condições de operação. Desta forma, os resultados foram divididos em testes, visando abordar o problema do chattering e diferenças do controlador proposto perante os convencionais. De maneira geral, a topologia de controle apresentou resultados melhores aos encontrados na literatura, podendo ser uma opção em sistemas que requerem acionamento de alto desempenho dinâmico. / This work deals with the vector control in a three-phase induction motor, applying the sliding mode theory to both the flux and the speed control loops in the Indirect Field Oriented Control strategy. It aims to improve the dynamic performance regarding the chattering problem. Therefore, the use of a smooth switching function is addressed, analyzing the outcomes achieved by different sliding surfaces. Based on these analysis, an Integral Sliding Mode Controller is proposed employing an integral sliding surface along with an anti-windup method based on a triangular function. In order to verify the attractiveness of the flux and the speed surfaces, an investigation regarding the use of a parametric portion as control action is carried out. The proposed control strategy is verified by means of simulations and experiments on test bench for different operating conditions. This way, the results are split in tests aiming to approach chattering problems and the differences between the proposed and traditional control strategies. Genarally, the outcomes of the proposed topology are better with those found on literature, pointing it as a viable choice to drive high dynamic performance demanding systems.
32

Modelling, simulation and analysis of low-cost direct torque control of PMSM using hall-effect sensors

Ozturk, Salih Baris 25 April 2007 (has links)
This thesis focuses on the development of a novel Direct Torque Control (DTC) scheme for permanent magnet (PM) synchronous motors (surface and interior types) in the constant torque region with the help of cost-effective hall-effect sensors. This method requires no DC-link sensing, which is a mandatory matter in the conventional DTC drives, therefore it reduces the cost of a conventional DTC of a permanent magnet (PM) synchronous motor and also removes common problems including; resistance change effect, low speed and integration drift. Conventional DTC drives require at least one DC-link voltage sensor (or two on the motor terminals) and two current sensors because of the necessary estimation of position, speed, torque, and stator flux in the stationary reference frame. Unlike the conventional DTC drive, the proposed method uses the rotor reference frame because the rotor position is provided by the three hall-effect sensors and does not require expensive voltage sensors. Moreover, the proposed algorithm takes the acceleration and deceleration of the motor and torque disturbances into account to improve the speed and torque responses. The basic theory of operation for the proposed topology is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation program written in MATLAB/SIMULINK® is used to verify the basic operation (performance) of the proposed topology. The mathematical model is capable of simulating the steady-state, as well as dynamic response even under heavy load conditions (e.g. transient load torque at ramp up). It is believed that the proposed system offers a reliable and low-cost solution for the emerging market of DTC for PMSM drives. Finally the proposed drive, considering the constant torque region operation, is applied to the agitation part of a laundry washing machine (operating in constant torque region) for speed performance comparison with the current low-cost agitation cycle speed control technique used by washing machine companies around the world.
33

Sensorless Vector Control Of Induction Motor Based On Flux And Speed Estimation

Ertugrul, Baris Tugrul 01 December 2008 (has links) (PDF)
The main focus of the study is the implementation of techniques regarding flux estimation and rotor speed estimation by the use of sensorless closed-loop observers. Within this framework, the information about the mathematical representation of the induction motor, pulse width modulation technique and flux oriented vector control techniques together with speed adaptive flux estimation &ndash / a kind of sensorless closed loop estimation technique- and Kalman filters is given. With the comparison of sensorless closed-loop speed estimation techniques, it has been attempted to identify their superiority and inferiority to each other by the use of simulation models and real-time experiments. In the experiments, the performance of the techniques developed and used in the thesis has been examined under extensively changing speed and load conditions. The real-time experiments have been carried out by the use of TI TMS320F2812 digital signal processor, XILINX XCS2S150E Field Programmable Gate Array (FPGA), control card and the motor drive card Furthermore, Matlab &ldquo / Embedded Target for the TI C2000 DSP&rdquo / and &ldquo / Code Composer Studio&rdquo / software tools have been used. The simulations and experiments conducted in the study have illustrated that it is possible to increase the performance at low speeds at the expense of increased computational burden on the processor. However, in order to control the motor at zero speed, high frequency signal implementation should be used as well as a different electronic hardware.
34

Modelling, simulation and analysis of low-cost direct torque control of PMSM using hall-effect sensors

Ozturk, Salih Baris 25 April 2007 (has links)
This thesis focuses on the development of a novel Direct Torque Control (DTC) scheme for permanent magnet (PM) synchronous motors (surface and interior types) in the constant torque region with the help of cost-effective hall-effect sensors. This method requires no DC-link sensing, which is a mandatory matter in the conventional DTC drives, therefore it reduces the cost of a conventional DTC of a permanent magnet (PM) synchronous motor and also removes common problems including; resistance change effect, low speed and integration drift. Conventional DTC drives require at least one DC-link voltage sensor (or two on the motor terminals) and two current sensors because of the necessary estimation of position, speed, torque, and stator flux in the stationary reference frame. Unlike the conventional DTC drive, the proposed method uses the rotor reference frame because the rotor position is provided by the three hall-effect sensors and does not require expensive voltage sensors. Moreover, the proposed algorithm takes the acceleration and deceleration of the motor and torque disturbances into account to improve the speed and torque responses. The basic theory of operation for the proposed topology is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation program written in MATLAB/SIMULINK® is used to verify the basic operation (performance) of the proposed topology. The mathematical model is capable of simulating the steady-state, as well as dynamic response even under heavy load conditions (e.g. transient load torque at ramp up). It is believed that the proposed system offers a reliable and low-cost solution for the emerging market of DTC for PMSM drives. Finally the proposed drive, considering the constant torque region operation, is applied to the agitation part of a laundry washing machine (operating in constant torque region) for speed performance comparison with the current low-cost agitation cycle speed control technique used by washing machine companies around the world.
35

Implementação de sistemas inteligentes em processadores digitais para controle de máquinas elétricas rotativas / Implementation of intelligent system in digital processor for rotative electric machine control

Marcelo Suetake 08 May 2008 (has links)
O objetivo deste trabalho consiste na implementação de arquiteturas de sistema inteligentes em Processadores Digitais de Sinais (DSP) visando, sobretudo, o controle em tempo real de motores de indução trifásicos. Para tanto, propõe-se uma abordagem fuzzy para o controle de velocidade de motores de indução trifásicos baseado na metodologia de ajuste de tensão e freqüência (Volts/Hertz) proveniente de um inversor PWM, de modo que o fluxo no entreferro seja mantido constante. O enfoque principal consiste no desenvolvimento do sistema de controle em hardware considerando o estudo dinâmico do controlador frente às variações de conjugado de carga, cujo desempenho da metodologia proposta será avaliado mediante simulações computacionais e ensaios experimentais realizados em laboratório. / The objective of this work consists of the implementation of intelligent system architecture in Digital Signal Processor (DSP) aiming at the real-time three-phase induction motor control. Therefore, a fuzzy logic speed control drive system for three-phase induction motor is proposed, whereas the control methodology is based on voltage and frequency (Volts/Hertz) adjustment of a PWM inverter so that the airgap flux maintains constant. The main focus concerns about hardware development of the control system considering the controller dynamic response study in relation to load torque variations, from which the proposed methodology performance is evaluated by means of computational simulation and experimental results obtained in laboratory.
36

Comparação de técnicas de controle de velocidade sensorless aplicadas a motores de indução em plataforma DSP / Comparison of speed sensorless control techniques applied to induction motors in a DSP platform

Martins, Orlando Saccol 31 March 2006 (has links)
This work proposes a comparative performance analysis of control and estimation techniques applied to three-phase induction motors with discrete realization, using a fixed-point digital signal processor based platform. Some modifications in original algorithms are proposed to improve the performance of the techniques in study. Initially, an historical review about the induction motors drives and a bibliographical review of the main speed estimation techniques implemented in DSP were accomplished. Then, different models of the induction machine are obtained using the semi-stationary reference frames. From the machine model, two speed controllers are projected: a classical PI controller, that is widely used in industrial environment and a robust model reference adaptive controller, objecting to compensate disturbances and unmodeled dynamics. After that, two estimation techniques based on 1M model are selected to project high-performance speed sensorless drives and later comparison. One of these schemes is extremely spread in academic and industrial environrnents, it is based on a model reference adaptive system (MRAS) and the other one is projected from a modified recursive least squares (MRLS), that is presented as a highperformance altemative solution. In the development of this work are displayed simulation results using the MatlabTM software, real-time simulations in DSP platform, and finally, experimental results. After these results analysis, it is possible to determinate which of these sensorless speed controllers proposed present satisfactory dynamic response for a wide range of speed, including low and null rotations, in situations of load disturbances and parametric variation. / Este trabalho propõe uma análise comparativa do desempenho de técnicas de controle e estimação de velocidade, com realização discreta no tempo, aplicadas a motores de indução trifásicos, utilizando plataforma com base em um processador digital de sinais de ponto-fixo. Algumas modificações em algoritmos existentes na literatura são propostas para melhorar o desempenho das técnicas em estudo. Inicialmente, uma revisão histórica sobre a evolução dos sistemas de acionamento para motores de corrente alternada e uma revisão bibliográfica das principais técnicas de estimação de velocidade implementadas em DSP são realizadas. Em seguida, são obtidos diferentes modelos para o motor de indução trifásico representados em referenciais semi-estacionários. A partir do modelo da máquina foram projetados dois controladores de velocidade: um controlador clássico e amplamente utilizado no meio industrial (PI), e, com o objetivo de compensar distúrbios e dinâmicas não modeladas, um controlador adaptativo robusto por modelo de referência (RMRAC) é implementado. Para o projeto de servomecanismos sensorless de alto desempenho, duas técnicas de estimação de velocidade baseadas no modelo do MI foram selecionadas. Uma delas é amplamente difundida. no meio acadêmico e industrial, sendo fundamentada em um sistema adaptativo por modelo de referência (MRAS) e outra tem base em um algoritmo de mínimos quadrados recursivos modificado (MRLS) e é apresentada como uma alternativa de alto desempenho. No desenvolvimento deste trabalho, resultados de simulações utilizando o software Matlab@, simulações em tempo-real em plataforma DSP, e por fim, resultados experimentais são apresentados. A partir destes resultados, parte-se para avaliação para determinar quais dos controladores sensorless analisados apresentam resposta dinâmica satisfatória em uma larga faixa de velocidade, inclusive em condições de velocidade baixa e nula, e também diante de situações de variação de carga e de parâmetros.
37

Implementação do controle de velocidade de motores síncronos a imãs permanentes em plataforma Labview FPGA / Labview FPGA speed control implementation for permanent magnet synchronous motors

Bevilaqua, Matheus Alexandre 04 February 2015 (has links)
Made available in DSpace on 2016-12-12T17:38:34Z (GMT). No. of bitstreams: 1 Matheus Alexandre Bevilaqua.pdf: 3412491 bytes, checksum: 4886770099c1ba6e43a5060a8dd7e00d (MD5) Previous issue date: 2015-02-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a new implementation for the vector control of synchronous permanent magnets motors based on Labview FPGA. A set of differential equations that describes the dynamic behavior of the electric and mechanical parts of the motor are presented and used to numerical simulations. These models are converted to transfer functions and block diagrams to allow the design of current and speed controllers. A design procedure for the current and speed controller is presented. This design procedure allows the designer to set the controller gains based on the system s desired bandwidth and damping ratio. Criteria to choose the bandwidth and damping ratio are established to obtain the maximum dynamic response of the motor. The designed controllers are verified by an integrated simulation of power electronics and control algorithm. This integrated simulation allows a number of analyses to be performed on the electric drive parameters. A verification of load inertia effect on the speed controllers is made. A power inverter modulation technique that maximizes the DC bus utilization is shown. Simulation and experimental results are provided to validate the technique. An experimental setup is developed in order to implement the motor controllers and allow the reproduction of this work. By using this setup, experimental results are given to demonstrate the implementation of the current controllers, PWM modulator and speed controller developed. The conclusions of this work and the next steps recommended to explore this new technology are given at the end of this document. / Este trabalho apresenta uma nova implementação do controle vetorial aplicado a motores síncronos de imãs permanentes utilizando o Labview FPGA. São desenvolvidos modelos matemáticos, baseados em equações diferenciais que descrevem as dinâmicas elétrica e mecânica do motor e permitem a simulação numérica do comportamento dinâmico do mesmo. Estes modelos são escritos também na forma de funções de transferência e diagrama de blocos, para permitirem o projeto dos controladores de corrente e velocidade. Um procedimento de projeto para os controladores de corrente e de velocidade do motor é apresentado. Este procedimento permite ao projetista determinar a banda passante e amortecimento desejados ao sistema. Critérios práticos são então estabelecidos para determinar a banda passante e amortecimento de forma a obter a máxima resposta dinâmica possível do motor. Os controladores projetados são verificados por meio de simulações numéricas integradas à eletrônica de potência necessária ao acionamento do motor. Estas simulações permitem a realização de diversas análises de sensibilidade do acionamento proposto. Uma análise da influência da inércia da carga no desempenho do controlador de velocidade é apresentada. Uma técnica de modulação do inversor de frequência que maximiza a utilização do barramento CC é apresentada e verificada por meio de simulação numérica. Resultados experimentais são fornecidos para validar a técnica descrita. Uma plataforma experimental para implementação dos controladores é desenvolvida e detalhada para permitir a reprodução do trabalho. Utilizando-se desta plataforma experimental, resultados são obtidos para demonstrar a implementação dos controladores de corrente, do modulador PWM e do controlador de velocidade apresentado neste trabalho. As conclusões são detalhadas e sugestões para explorar a tecnologia desenvolvida neste trabalho são feitas ao final do documento.
38

Intelligent löpband : Hastighetsreglering efter användarens rörelse och ökad säkerhet

Rosell, Daniel January 2017 (has links)
Det finns ett behov av billiga löpband som reglerar hastighet automatiskt efter användarens steg. Behovet finns främst inom vården för rehabilitering av patienter med olika rörelse- eller balansproblem där nuvarande lösningar ofta är mycket dyra. Fördelar är att kunna förbättra behandling, öka tillgänglighet och öka säkerhet utan att kräva utrustning på användaren. För att lösa detta skapades ett system med löpband och sensorer som kan följa användarens position och kroppshållning och reglera löpbandets hastighet efter detta. Kroppshållning följs av en algoritm som identifierar risker som tecken på tappad balans eller fall och bandet bör saktas ner eller stoppas. En prototyp skapades under ett tidigare projekt men denna hade problem och svagheter. Problem med lasersensorn för avståndsmätning undersöktes och tröghet i löpbandets styrning testades. För att undvika trögheten gjordes försök att ta reda på löpbandets kommunikationsprotokoll för att uppnå närmare motorstyrning. Nya algoritmer för hastighetsreglering och riskdetektering skapades. Det ursprungliga systemet gjordes om för att lägga till nya funktioner och tester. Resultat visar att sensorproblemen berodde på elektromagnetisk interferens från löpbandet som störde sensorns I2C-protokoll. Jämförelse mellan laser och Kinect visar att lasern inte behövs och att Kinect-sensorn ger stabilare mätningar. Det nya systemets mjukvara ger en mer modulär testmiljö för algoritmer. Det kan vara svårt att anpassa löpband beroende på konstruktion utan att bygga om för att uppnå en mjuk hastighetsreglering. Systemet och algoritmerna kan med lämplig styrmetod uppnå reglering av hastighet efter användarens rörelse och ge ökad säkerhet. / Needs exist for cheap treadmills that control speed automatically according to the user's step. Needs are primarily in healthcare for rehab involving patients with different mobility and balance issues for which current solutions are very expensive. Pros are the ability to improve treatment, increase availability and safety without the need for equipment worn by the user. To solve this a system consisting of treadmill and sensors was created. The system can track the user's position and posture and control the treadmill's speed accordingly. Posture is tracked by an algorithm that identifies risks as signs of lost balance and fall indicating that the treadmill should slow down or stop. A prototype was created during an earlier project but it had problems and weaknesses. Issues with the laser sensor used for measuring distance were investigated and delay in the control of the treadmill's motor was tested. To avoid the delay attempts were made to identify the communication protocol used by the treadmill to achieve better speed control. New algorithms for speed control and risk detection were created. The original system was modified to add new functionality and tools for testing. Results show that the sensor issues were caused by electromagnetic interference from the treadmill interfering with the I2C-protocol used with the sensor. A comparison of the laser and kinect show that the laser is not needed and that the Kinect is more stable. The new system's software creates a more modular environment for testing algorithms. It can be difficult to adjust treadmills depending on their construction without rebuilding them to reach a smoother speed control. The system and algorithms can given an appropriate motor control scheme achieve the purpose.
39

Servocontrole de velocidade aplicado a motores de indução monofásicos sem sensores mecânicos / Servo control of speed applied to single-phase induction motors without speed sensor

Vieira, Rodrigo Padilha 31 October 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work proposes a sensorless speed control applied to single-phase induction motors (SPIM). The objective is to present an alternative for variable speed single-phase motor drives for residencial applications, which operate mostly with constant speed. For contextualization in the actual scenario, firstly a bibliographic review about variable speed operation of single-phase induction motors is presented. After, the mathematical model that represents the single-phase induction motor dynamic behavior is developed, and following, the model validation to obtain the electrical parameters is done with classical experimental tests. Then, a field orientation technique applied to single-phase induction motors is presented, where a new mathematical model is developed for the application of this technique in this motor. Also, this work proposes a method of single-phase induction motors rotor speed estimation using an MRAS (Model Reference Adaptive System) algorithm, based on the calculation of the motor s reactive power. So, some simulation results are presented for the validation of the proposed estimation technique. The speed controller used is a discrete PI because the simplicity of its implementation. Two discrete PI s controllers are used for current control. Finally, experimental results obtained in a computer based environment are presented to validate the proposed techniques with and without rotor speed sensor. / Este trabalho propõe um controle de velocidade sensorless aplicado a motores de indução monofásicos. Tem-se por objetivo proporcionar uma alternativa de acionamento com velocidade variável dos motores de indução monofásicos em aplicações residenciais, nas quais estes geralmente operam em velocidades fixas. Para contextualização do tema no cenário atual, inicialmente é apresentada uma revisão da literatura quanto aos acionamentos a velocidade variável de motores de indução monofásicos. A partir da revisão da literatura é desenvolvido o modelo matemático que representa o comportamento dinâmico do motor de indução monofásico e, juntamente com este tópico, a validação do modelo para obtenção dos parâmetros elétricos é feita a partir de ensaios clássicos. Em seguida, é apresentada uma técnica de controle por orientação no campo aplicada a motores de indução monofásicos, com a obtenção de um novo modelo matemático onde essa técnica possa ser aplicada. Além disso, esse trabalho propõe um método de estimação da velocidade rotórica de motores de indução monofásicos a partir de um algoritmo MRAS (Model Reference Adaptive System), baseado no cálculo da potência reativa deste motor. Com isso, são apresentados resultados de simulação para validação da técnica de estimação proposta. O controlador de velocidade escolhido é um PI discreto, que teve sua escolha definida pela simplicidade de implementação. Dois controladores PI s discretos também são usados para o controle das malhas de corrente. Por fim, são apresentados resultados experimentais desenvolvidos em plataforma computadorizada que validam as técnicas propostas, tanto no controle de velocidade com a medição da mesma, como no controle de velocidade sem o uso do sensor.
40

Adaptiv varvtalsstyrning vid användning av en lastbils kraftuttag / Adaptive speed control for truck PTO usage

Claesson, Adam January 2010 (has links)
Med ett växande fokus på ett långsiktigt hållbart samhälle som tar ansvar för miljön strävar fordonstillverkare efter att sänka energiförbrukningen på sina fordon. Detta arbete behandlar hur man kan sänka bränsleförbrukningen för lastbilar med påbyggnader. En påbyggnad kan t.ex. vara en kran, en lastväxlare eller en betongpump. En metod för att sänka energiförbrukningen är att sänka det varvtal som lastbilens dieselmotor arbetar vid. Vid lägre varvtal jobbar motorn oftast mer effektivt och en mindre del av motorarbetet försvinner då i förluster, dock kan inte motorn belastas lika hårt. Varvtalet kan i vissa situationer sänkas under drift av påbyggnaden. Mellan drift då applikationen väntar på användarens kommando kan varvtalet alltid sänkas så att energiförbrukningen sjunker.För att veta när varvtalet ska sänkas används en signal från motorn som anger vilket lastmoment som motorn jobbar mot. Vid låg last sänks varvtalet och bränsle kan sparas, vid hög last höjs varvtalet för att kunna möta det pålagda momentet.Fältstudier har genomförts för att kunna undersöka vilka typer av lastbilspåbyggnader som skulle kunna ha nytta av en funktion som sänker varvtalet när lasten är låg. Under arbetet har även uppskattningar över hur mycket bränsle som skulle kunna sparas om varvtalet sänks mellan operationerna med påbyggnaden gjorts. Resultatet pekar på att det i många fall går att spara bränsle genom att sänka motorns varvtal då lastbilens påbyggnad inte används. De visar också på att det inte går att spara bränsle med denna metod i de fall där föraren sitter kvar i hytten under påbyggnadsanvändningen.

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