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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.
11

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.
12

Estratégias de controle direto de torque para motores de indução trifásicos usando controladores fuzzy tipo Takagi-Sugeno e controladores por modos deslizantes / Direct torque control strategies for three-phase induction motors with Takagi-Sugeno fuzzy controllers and sliding mode controllers

Azcue Puma, José Luis, 1981- 22 August 2018 (has links)
Orientador: Ernesto Ruppert Filho, Alfeu Joãozinho Sguarezi Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-22T11:09:49Z (GMT). No. of bitstreams: 1 AzcuePuma_JoseLuis_D.pdf: 5829554 bytes, checksum: 6f4467c529a778cc79e42550a272a6b3 (MD5) Previous issue date: 2013 / Resumo: Na presente tese de doutorado propõe estratégias de controle por orientação direta de campo (FOC direto) e de controle direto de torque (CDT) com emprego de controladores fuzzy do tipo Takagi-Sugeno (fuzzy T-S). Propõe-se também, uma estratégia de CDT baseado no controle do ¿angulo de carga com o emprego do controle por modos deslizantes (CDT-CMD). As estratégias de controle vetorial propostas são utilizadas para o controle de alto desempenho do motor de indução trifásico. O controlador fuzzy T-S proposto utiliza uma única base de regras para gerar as componentes de eixo direto e de quadratura do vetor espacial da tensão do estator. Isto simplifica a estrutura do controlador fuzzy T-S e em consequência diminui o custo computacional e seu tempo de processamento. Na estratégia de CDT com o controle por modos deslizantes o esforço de controle é sempre o máximo possível no sentido de reduzir os erros do torque e do fluxo. Assim, é possível obter uma resposta rápida no controle do fluxo e do torque. Os resultados de simulação e experimentais são apresentados para validarem as propostas desta tese de doutorado. Os controladores apresentaram um desempenho dinâmico satisfatório pois as referências de torque e de fluxo foram atendidas. Todos os resultados obtidos mostraram-se compatíveis com os resultados apresentados na literatura, validando as estratégias de CDT e de FOC direto propostas / Abstract: This thesis proposes a direct field oriented control (D-FOC) and direct torque control (DTC) strategies with Takagi-Sugeno fuzzy controllers (T-S fuzzy). Also it proposes a DTC strategy based on load angle control with the use of sliding mode control (DTC-SMC). The proposed vector control strategies are used for high performance control of three-phase induction motor. The proposed T-S fuzzy controller uses a single rule base to generate the direct-axis and quadrature-axis components of the stator voltage space vector. This simplifies the structure of the T-S fuzzy controller and consequently it reduces the computational cost and its processing time. However, in the sliding mode control the control effort is always the maximum possible in order to reduce the errors of the torque and the flux. Hence, it is possible to get a fast response in the control of the torque and the flux. The proposed controllers showed a good dynamic performance because the references were achieved. The experimental and simulation results of the vector control strategies were presented to validate the proposed controllers. All the obtained results were consistent with the results reported in the literature, validating the proposed DTC and D-FOC strategies / Doutorado / Energia Eletrica / Doutor em Engenharia Elétrica
13

Investigation of Control Concepts for High-Speed Induction Machine Drives and Grid Side Pulse-Width Modulation Voltage Source Converters

Jalili, Kamran 26 February 2009 (has links)
Control of a low voltage ac/dc/ac converter for high-speed induction machine drive applications has been investigated. Such a configuration can be applied, for example, in microturbines and high-speed spindles. Scalar control is usually applied for the control of high-speed drives especially in the case of very high-speed drives. Indirect rotor-flux-oriented control and direct torque control are designed and compared for the control of an exemplary high-speed induction machine drive. The 2L VSC is the most widely applied converter for high-speed drives. However, the 3L-NPC VSC is an attractive topology if drastically increased switching frequencies are required. A detailed comparison between a 2L VSC and a 3L-NPC VSC as the machine side converter of the exemplary high-speed induction machine drive is carried out. Voltage-oriented control is applied for the control of the grid side PWM active front end converter. In several industrial applications PWM active front end converters commonly operate in parallel to thyristor converter fed dc drives. Behavior of the voltage-oriented controlled active front end converter with L-filter in the presence of a parallel thyristor converter is investigated. The design of the LCL-filter components according to the given maximum grid current harmonics (e.g. IEEE-519) is a complex task. So far a precise and clear design procedure has not been presented. A new procedure to design the grid side filter (L- and LCL-filter) is proposed using the analytical expression of the converter voltage harmonics based on Bessel functions to achieve the compliance with the grid standard of IEEE-519. Voltage-oriented control with active damping is used to control the active front end converter with LCL-filter. A simple method is proposed to design the required lead-lag compensator in the active damping loop.
14

Optimised space vector modulation for variable speed drives

Khan, Hamid 06 November 2012 (has links) (PDF)
The dissertation documents research work carried out on Pulse Width Modulation (PWM) strategies for hard switched Voltage Source Inverters (VSI) for variable speed electric drives. This research is aimed at Hybrid Electric Vehicles (HEV). PWM is at the heart of all variable speed electric drives; they have a huge influence on the overall performance of the system and may also help eventually give us an extra degree of freedom in the possibility to rethink the inverter design including the re-dimensioning of the inverter components.HEVs tend to cost more than conventional internal combustion engine (ICE) vehicles as they have to incorporate two traction systems, which is the major discouraging factor for consumers and in turn for manufacturers. The two traction system increases the maintenance cost of the car as well. In addition the electric drives not only cost extra money but space too, which is already scarce with an ICE under the hood. An all-electric car is not yet a viable idea as the batteries have very low energy density compared with petrol or diesel and take considerable time to charge. One solution could be to use bigger battery packs but these add substantially to the price and weight of the vehicle and are not economically viable. To avoid raising the cost of such vehicles to unreasonably high amounts, autonomy has to be compromised. However hybrid vehicles are an important step forward in the transition toward all-electric cars while research on better batteries evolves. The objective of this research is to make electric drives suitable for HEVs i.e. lighter, more compact and more efficient -- requiring less maintenance and eventually at lower cost so that the advantages, such as low emissions and better fuel efficiency, would out-weigh a little extra cost for these cars. The electrical energy source in a vehicle is a battery, a DC Voltage source, and the traction motor is generally an AC motor owing to the various advantages it offers over a DC motor. Hence the need for a VSI, which is used to transform the DC voltage into AC voltage of desired amplitude and frequency. Pulse width modulation techniques are used to control VSI to ensure that the required/calculated voltage is fed to the machine, to produce the desired torque/speed. PWM techniques are essentially open loop systems where no feedback is used and the instantaneous values differ from the required voltage, however the same average values are obtained. Pulse width modulated techniques produce a low frequency signal (desired average value of the switched voltage) also called the fundamental component, along with unwanted high frequency harmonics linked to the carrier signal frequency or the PWM period. In modern cars we see more and more mechanical loads driven by electricity through digital processors. It is very important to eliminate the risk of electromagnetic interference between these systems to avoid failure or malfunction. Hence these unwanted harmonics have to be filtered so that they do not affect the electronic control unit or other susceptible components placed in the vicinity. Randomised modulation techniques (RPWM) are used to dither these harmonics at the switching frequency and its multiple. In this thesis a random modulator based on space vector modulation is presented which has additional advantages of SVM. Another EMI problem linked to PWM techniques is that they produce common mode voltages in the load. For electric machines, common mode voltage produces shaft voltage which in turn provokes dielectric stress on the motor bearings, its lubricant and hence the possibility of generating bearing currents in the machine that can be fatal for the machine. To reduce the common mode voltage a space vector modulation strategy is developed based on intelligent placement of zero vectors. (...)
15

Acionamento do motor síncrono de imãs permanentes usando DSP / Synchronous permanent magnet motor drive system control

Sperb, Elisabeth Cristina Lemos 05 August 2011 (has links)
Made available in DSpace on 2016-12-12T20:27:39Z (GMT). No. of bitstreams: 1 ELISABETH CRISTINA LEMOS SPERB.pdf: 4249399 bytes, checksum: 689cbb6a5cf388bda83e27d4de4a8e1a (MD5) Previous issue date: 2011-08-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This project presents the implementation of an experimental test bed to drive the permanent magnet synchronous motor (PMSM) using a digital signal processor. The main purpose of the project is to develop a test bed with flexible features enabling the implementation and evaluation of different motor control techniques. Initially the constructive characteristics of the PMSM are studied, as the selection of the proper materials of permanent magnets and the possibilities of physical arrangement in the rotor. Then the mathematical model is developed with the currents and voltage equation in the rotating reference frame. An analysis is made, consequently, of the vector control using the method by considering the rotor flux approach with constant torque control and the space vector pulse width modulation technique. Some techniques of sensorless control based on the motor mathematical model and artificial neural network are also presented. To demonstrate the flexibility of the bed developed, some algorithms for estimating motor position and speed, earlier simulated, were implemented with the algorithm drive system. / Neste trabalho é apresentada a implementação de uma bancada experimental para o acionamento do motor síncrono de imãs permanentes (MSIP) utilizando um processador digital de sinais. O objetivo principal do trabalho é desenvolver uma bancada com características flexíveis que permita a implementação e avaliação de técnicas de controle variadas. Inicialmente, são estudadas as características construtivas do MSIP, como o material que compõe os imãs permanentes e as possibilidades de arranjo físico no rotor. Em seguida é desenvolvido o modelo matemático com as equações de corrente e tensão no referencial girante. É analisado na seqüência, o controle vetorial, utilizando o método direto pelo fluxo de rotor considerando a abordagem com controle de torque constante, e a técnica de modulação por largura de pulso por vetor espacial. São também apresentadas algumas técnicas de controle sem sensor de posição/velocidade (sensorless) baseadas no modelo matemático do motor e em redes neurais artificiais. Algumas técnicas de controle sensorless foram simuladas e analisadas. Para comprovar a flexibilidade da bancada desenvolvida, alguns algoritmos de estimação da posição e velocidade do motor, anteriormente simulados, foram implementados juntamente com o algoritmo de acionamento.
16

Electric turbocharger for fuel cells - IHI´s contribution to sustainable mobility

Filsinger, Dietmar, Ehrhard, Jan, Kuwata, Gen, Ikeya, Nobuyuki 27 May 2022 (has links)
Towards a carbon free society the IHI group is committed to provide products, technologies and services in line with ecological and economical sustainability. Storage and transportation of green energy are major challenges related to the global transition from fossil fuels towards 100% renewables. IHI is active in various areas ranging from SOFC technology via ammonia combustion to smart community demonstrator projects. With respect to mobility hydrogen fuel cell technology is identified as one major pillar for CO2-neutral vehicular propulsion – especially for higher payloads and extended driving distances. Since more than 20 years IHI is providing charging systems for stationary fuel cell applications and since 2004 also for mobile fuel cell applications. IHI´s oil free turbocharger for fuel cell applications is providing state-of-the-art boosting technology to enable emission free propulsion systems. It comprises a turbine, a compressor and, on the same shaft, an electric motor as well as air foil bearings to support the rotor. The turbine utilizes the enthalpy from the stack exhaust to lower the required electric power for driving the compressor. It can provide up to 40% of the needed compressor power and hence substantially increases the system efficiency. Compressor and turbine are optimized for operating conditions in fuel cell systems regarding specified airflow and pressure ratio, which is typically in the range of 3.0.
17

A Heterogeneous Multirate Simulation Approach for Wide-bandgap-based Electric Drive Systems

Olatunji T Fulani (9581096) 27 July 2021 (has links)
<p>Recent developments in semiconductor device technology have seen the advent of wide-bandgap (WBG) based devices that enable operation at high switching frequencies. These devices, such as silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs), are becoming a favored choice in inverters for electric drive systems because of their lower switching losses and higher allowable operating temperature. However, the fast switching of such devices implies increased voltage edge rates (high <i>dv/dt</i>) that give rise to various undesirable effects including large common-mode currents, electromagnetic interference, transient overvoltages, insulation failure due to the overvoltages, and bearing failures due to</p> <p>microarcs. With increased use of these devices in transportation and industrial applications, it is imperative that accurate models and efficient simulation tools, which can predict these high-frequency effects and accompanying system losses, be established. This research initially focuses on establishing an accurate wideband model of a surface-mount permanent-magnet</p> <p>ac machine supplied by a WBG-based inverter. A new multirate simulation framework for predicting the transient behavior and estimating the power losses is then set forth. In this approach,</p> <p>the wideband model is separated into high- and low-frequency models implemented using two different computer programs that are best suited for the respective time scales. Repetitive execution of the high-frequency model yields look-up tables for the switching losses in the semiconductors, electric machine, and interconnecting cable. These look-up tables are then incorporated into the low-frequency model that establishes the conduction</p> <p>losses. This method is applied to a WBG-based electric drive comprised of a SiC inverter and permanent-magnet ac machine. Comparisons of measured and simulated transients are provided.</p>
18

Estratégias de acionamento e controle em máquinas CA de ímã permanente com fluxo não senoidal / Control strategies for permanent magnet AC machines with non-sinusoidal flux

Monteiro, José Roberto Boffino de Almeida 29 August 1997 (has links)
O objetivo desse trabalho é o estudo e a análise do desempenho de máquinas brushless com ímã permanente no rotor, com fluxo de entreferro não senoidal. São consideradas máquinas brushless com ímã permanente na superfície do rotor. Três modelos matemáticos são considerados: o modelo por fase de estator, o modelo vetorial e o modelo velocidade-tensão de segunda ordem. Máquinas com diferentes tipos de enrolamento de estator são comparadas, incluindo as máquinas síncronas com ímã permanente no rotor (com a densidade dos enrolamentos distribuída de forma senoidal no estator). Os resultados para o torque eletromagnético das máquinas foram obtidos considerando-se dois tipos de acionamentos em malha aberta: um acionamento de seis pulsos e um acionamento senoidal. Por fim, um método de controle é apresentado para máquinas não senoidais. As ondulações no torque e o desempenho das máquinas não senoidais. As ondulações no torque e o desempenho das máquinas não senoidais, utilizando controle vetorial, são comparados aos das máquinas senoidais. / The aim of this work is to analyse the torque performance of brushless machines with non-sinusoidal distributed magnetic fluxes. The machine type considered is a surface mount permanent magnet brushless machine. Three mathematical models for the machine are considered: the per stator phase, the vectorial and the linear second order speed-voltage models. Machines with different stator windings are compared including the permanent magnet synchronous machines with sinusoidal distributed stator windings. The torque outputs of these machines are obtained considering two kinds of open loop driving systems: one with a six-pulse waveform and other with a sinusoidal waveform. Finally, a vectorial control is proposed for the non-sinusoidal machines. The torque ripple as well the overall performance of non-sinusoidal machines with vectorial control is compared to that of sinusoidal machines.
19

Dispositif correcteur de facteur de puissance à base de super-condensateur pour variateur de vitesse / Ultra-capacitor based regenerative energy storage and power factor correction device for controlled electric drives

Grbovic, Petar 09 July 2010 (has links)
Les variateurs de vitesse modernes sont exclusivement basés sur l’utilisation de moteurs triphasés alimentés par des onduleurs à modulation de largeur d’impulsion (MLI). La plupart des applications modernes de la variation de vitesse, comme les ascenseurs, les grues et les machines-outils sont caractérisées principalement par un rapport élevé entre la puissance crête et la puissance moyenne et une forte demande de freinage à la puissance nominale. Dans les variateurs de vitesse ordinaires, l’énergie de freinage, qui est de l’ordre de 30 à 50% de l’énergie consommée, est dissipé dans une résistance. Outre les problèmes « énergétiques », les interruptions et dégradations de la tension d’alimentation ainsi que la qualité du courant d’entrée et la fluctuation de la charge, sont d’autres questions à aborder et à résoudre.Le super-condensateur dédié aux applications de conversion de puissance est ainsi proposé. Un variateur de vitesse équipé avec des super-condensateurs est présenté dans la thèse. Les super-condensateurs, interconnectés par un convertisseur DC-DC sont utilisés pour stocker et ré-injecter l'énergie de freinage. De plus, le convertisseur DC-DC contrôle le courant du redresseur et la tension du bus DC. Le THD du courant d’entrée est ramené à 30%. La tension du bus DC est élevée et en permanence contrôlée et lissée indépendamment de la charge et de la variation de la tension réseau. Pour terminer, les pics de puissance peuvent être lissés. La solution présentée est analysée théoriquement et vérifiée par un ensemble de simulations et expérimentations. Les résultats sont présentés et commentés / Modern controlled electric drives are exclusively based on three-phase motors that are fed from three-phase pulse width modulated (PWM) inverters. Most of modern controlled electric drive applications, such as lifts, cranes and tooling machines are characterized by high ratio of the peak to average power, and high demand for braking at the rated power. In ordinary drives, the braking energy, which represents 30-50% of the consumed energy, is dissipated on a braking resistor. Apart from the “energetic” issue, the mains interruption and degradation, the input current quality and the load fluctuation are additional issues to be addressed and solved.The ultra-capacitor dedicated for power conversion applications has been discussed. In comparison to electrochemical batteries, the ultra-capacitors have higher power density and efficiency, longer life time and greater cycling capability. This makes the ultra-capacitor an excellent candidate for power conversion applications.A new electric drive converter equipped with the ultra-capacitor is presented in the dissertation. The ultra-capacitor with an inter-connection dc-dc converter is used to store and recover the drive braking energy. Moreover, the dc-dc converter controls the rectifier current and the dc bus voltage. The drive input current THD is reduced to 30%. The dc bus voltage is boosted and controlled constant and ripple free regardless on the load and the mains voltage variation. Moreover, the drive input peak power can be smoothed. The presented solution is theoretically analysed and verified by set of simulations and experiments. The results are presented and discussed
20

Estudo do acionamento do motor síncrono de ímãs permanentes: abordagem baseada no controle vetorial com ângulo de torque constante

Sá, Franciéli Lima de 30 July 2010 (has links)
Made available in DSpace on 2016-12-12T17:38:37Z (GMT). No. of bitstreams: 1 FRANCIELI LIMA DE SA.pdf: 957791 bytes, checksum: 54a198d079685e3726016b54e682ffdc (MD5) Previous issue date: 2010-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work is introduced a study of Permanent Magnet Synchronous Motor (PMSM), involving issues about constructive characteristics, modeling, control and simulation. Initially, are studied the constructive characteristics, principally in that refers of the magnets disposition in the rotor. Then, are shown some applications for the PMSM. The mathematic model of PMSM is developed starting of stationary reference frame and utilizing the rotation transformation for obtain the equations of currents and voltage in the rotor reference frame. The feed shape of the PMSM is an analysis of extreme importance in the study of this motor, for this reason also is show in this work. The vector control is analyzed in the sequence, utilizing the direct method for the rotor flux and considering the approach with Constant torque control. Are presents some techniques for the design of controllers of speed and current loops. Through the performed simulations, are analyzed and compared the several technical approached. The results obtained show that the vector control approach with constant torque angle applied to the PMSM presents a good dynamic response for motor drive. / Neste trabalho, é apresentado um estudo do Motor Síncrono de Ímãs Permanentes (MSIP) envolvendo questões pertinentes às características construtivas, modelamento, controle e simulação. Inicialmente, são estudadas as características construtivas, principalmente no que se refere à disposição dos ímãs no rotor. Em seguida são mostradas algumas aplicações para o MSIP. O modelo matemático do MSIP é desenvolvido partindo do referencial estacionário e utilizando a transformação de rotação para se obter as equações de corrente e tensão no referencial girante. A forma de alimentação do MSIP é uma análise de extrema importância no estudo deste motor, e por esta razão também é mostrada neste trabalho. O controle vetorial é analisado na seqüência, utilizando o método direto pelo fluxo de rotor e considerando a abordagem com controle de torque constante. São apresentadas algumas técnicas para o projeto dos controladores das malhas de corrente e velocidade. Através das simulações realizadas, são analisadas e comparadas as diversas técnicas abordadas. Os resultados obtidos mostram que o controle vetorial com abordagem do ângulo de torque constante aplicado ao MSIP apresenta uma boa resposta dinâmica para o acionamento do motor.

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