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This study investigates the application of adaptive time-suboptimal positional control to an electrical machine with a wide range of loading conditions. These unpredicatable load conditions included variable system parameters, such as inertia variations and nonlinear amplification gain in the servo driver, as well as external disturbances, including viscous frictional force, coulomb frictional force and static loading torque. The design objective was to provide an extremely fast positional movement to the desired target without overshoot and zero steady-state error over these loading conditions. The resultant microcontroller-based adaptive controller consists of an on-line parameter estimator and a robust time-(sub)optimal position controller. The system parameters are estimated by an recursive least squares (RLS) estimator during the acceleration phase. The sampling frequency used by the RLS algorithm is determined adaptively. During the crusing phase of the positional movement, the estimates are further improved by feeding intersample data (stored during the acceleration phase) through an off-line RLS estimator. The coulomb friction and the static loading torque are effectively compensated by a simple mechanism. Another novel mechanism which takes account of nonlinear amplifier gain has also been developed. The time-(sub)optimal position controller calculates the desired reference trajectory in real-time and directs the system state to the reference trajectory. The above adaptive control scheme was implemented on a microcontroller-based system and was applied to an experimental system consisting of a 500W DC permanent magnet motor fed by a pwm servo driver. Experimental results revealed that the proposed controller adapted well to changes in inertia, viscous friction, coulomb friction and amplifier nonlinearity, and the desired time-suboptimal respones were obtained in all these loading conditions.

Orientador: Ernesto Ruppert Filho / Tese (doutorado)) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e Computação / Made available in DSpace on 2018-08-23T16:55:43Z (GMT). No. of bitstreams: 1 LuqueCarcasi_DiodomiroBaldomero_D.pdf: 4622553 bytes, checksum: bb71dd897d06fd750e2849f700a8128e (MD5) Previous issue date: 2012 / Resumo: Este trabalho é uma contribuição ao estudo da determinação de parâmetros de geradores síncronos trifásicos de pólos salientes. A partir da literatura disponível sobre projeto de máquinas, inicia-se o desenvolvimento do dimensionamento do gerador síncrono trifásico de pólos salientes através de sucessivos cálculos realizados para as principais dimensões físicas da mesma. Com base nos dados iniciais de projeto e utilizando um software comercial de projeto de máquinas, foram realizados cálculos e detalhes do projeto obtendo-se os parâmetros operacionais do gerador síncrono trifásico de pólos salientes. A seguir, foram realizadas simulações dinâmicas do gerador utilizando métodos estandardizados com o intuito de determinar seus respectivos parâmetros operacionais, entre eles estão: o ensaio de curto circuito trifásico brusco, ensaio de rejeição de carga e ensaio de resposta em frequência, em todos os casos utilizou-se as técnicas de elementos finitos e um software comercial da Ansoft. Os dados obtidos nas simulações dos ensaios foram tratados matematicamente baseados nas normas IEEE Std 115 e IEC 34-4 para a obtenção dos valores dos parâmetros operacionais do gerador. Comparações entre os valores de projeto e os obtidos pelo método de elementos finitos foram realizadas mostrando que essa metodologia pode ser utilizada para complementar aos ensaios reais / Abstract: This work is a contribution to the study of the parameters determination of a salient-pole synchronous generator. From the available literature on machine design, it begins the project development of the three-phase synchronous generator through successive calculations performed for the main physical dimensions. Based on the initial data for design and using commercial software for machine design, we performed calculations and design details obtaining the operational parameters of the synchronous generator. Next, dynamic simulations for three-phase synchronous machine were performed using standard methods in order to determine their operating parameters as simulation of the three-phase sudden short-circuit tests, load rejection and standstill frequency response test, in all cases we used the finite elements techniques and ANSOFT commercial software for this. The data obtained in the simulations tests have been processed mathematically based on IEEE Std 115 and IEC 34-4 standards and the operating parameters values were obtained from the generator. Comparisons between the design values and those obtained by finite element method were performed showing that this methodology can be used to complement the actual test / Doutorado / Automação / Mestre em Engenharia Elétrica

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Neste trabalho desenvolve-se uma análise sobre o estado da arte e tendências para projeto de geradores elétricos em turbinas eólicas offshore. A conjunção dos requerimentos de alta confiabilidade e potência, criam condições adequadas para a aplicação de máquina elétricas multifásicas nesse setor. Desta forma, optou-se por estudar as características e condições de projeto de máquinas elétricas multifásicas, simétricas ou assimétricas. Com esta finalidade, os métodos analíticos de projeto de máquinas elétricas trifásicas são revisitados e estendidos, quando necessário, para diferentes configurações multifásicas. O foco do trabalho, consiste em desenvolver e explorar temas de projeto de geradores elétricos multifásicos, síncronos de imãs permanentes, com enrolamentos distribuídos de dupla camada. Para estudo de caso, realiza-se a comparação entre o projeto de quatro topologias diferentes. Nomeadamente, compara-se o projeto de geradores de três, seis, nove e dezoito fases para turbinas eólicas offshore de 10 MW. A configuração com gerador de nove fases apresenta os melhores resultados, com densidade de torque 10,96% superior à densidade de torque desenvolvida pela máquina trifásica analisada. Por fim, a metodologia analítica desenvolvida para o projeto de máquinas elétricas multifásicas é verificada usando o método de elementos finitos bidimensional, para o gerador síncrono de imãs permanentes de nove fases. / The state of the art and future trends for offshore wind turbines were reviewed. Due to its fault-tolerant characteristic, multiphase electrical generators were identified as strong candidates to meet the power and resilience targets of the offshore wind sector. In this work, the design aspects of three-phase electrical machines are reviewed and extended to different multiphase configurations. The main focus of the work is to develop an analytical design methodology for multiphase, symmetrical and asymmetrical, synchronous generators with double-layer distributed windings. As a case study, the project of a three-phase, six-phase, nine-phase and eighteen-phase permanent magnet synchronous generators were compared for a 10MW offshore wind turbine. The best results were found for the nine-phase topology, with a torque density 10.96% higher than the torque density of the analysed three-phase machine. The developed design methodology was validated with a finite element analysis of the ninephase permanent magnet generator.

Neste trabalho desenvolve-se uma análise sobre o estado da arte e tendências para projeto de geradores elétricos em turbinas eólicas offshore. A conjunção dos requerimentos de alta confiabilidade e potência, criam condições adequadas para a aplicação de máquina elétricas multifásicas nesse setor. Desta forma, optou-se por estudar as características e condições de projeto de máquinas elétricas multifásicas, simétricas ou assimétricas. Com esta finalidade, os métodos analíticos de projeto de máquinas elétricas trifásicas são revisitados e estendidos, quando necessário, para diferentes configurações multifásicas. O foco do trabalho, consiste em desenvolver e explorar temas de projeto de geradores elétricos multifásicos, síncronos de imãs permanentes, com enrolamentos distribuídos de dupla camada. Para estudo de caso, realiza-se a comparação entre o projeto de quatro topologias diferentes. Nomeadamente, compara-se o projeto de geradores de três, seis, nove e dezoito fases para turbinas eólicas offshore de 10 MW. A configuração com gerador de nove fases apresenta os melhores resultados, com densidade de torque 10,96% superior à densidade de torque desenvolvida pela máquina trifásica analisada. Por fim, a metodologia analítica desenvolvida para o projeto de máquinas elétricas multifásicas é verificada usando o método de elementos finitos bidimensional, para o gerador síncrono de imãs permanentes de nove fases. / The state of the art and future trends for offshore wind turbines were reviewed. Due to its fault-tolerant characteristic, multiphase electrical generators were identified as strong candidates to meet the power and resilience targets of the offshore wind sector. In this work, the design aspects of three-phase electrical machines are reviewed and extended to different multiphase configurations. The main focus of the work is to develop an analytical design methodology for multiphase, symmetrical and asymmetrical, synchronous generators with double-layer distributed windings. As a case study, the project of a three-phase, six-phase, nine-phase and eighteen-phase permanent magnet synchronous generators were compared for a 10MW offshore wind turbine. The best results were found for the nine-phase topology, with a torque density 10.96% higher than the torque density of the analysed three-phase machine. The developed design methodology was validated with a finite element analysis of the ninephase permanent magnet generator.

<p> This thesis studies critical zones of automated vehicles. The goal is for the automated vehicle to complete a car-following or lane change maneuver without collision. For instance, the automated vehicle should be able to indicate its interest in changing lanes and plan how the maneuver will occur by using model predictive control theory, in addition to the autonomous vehicle toolbox in Matlab. A test bench (that includes a scenario creator, motion logic and planner, sensors, and radars) is created and used to calculate the parameters of a critical zone. After a trajectory has been planned, the automated vehicle then attempts the car following or lane change while constantly ensuring its safety to continue on this path. If at any point, the lead vehicle brakes or a trailing vehicle accelerates, the automated vehicle makes the decision to either brake, accelerate, or abandon the lane change. </p>

The aim of this research is to increase the current density of electrical machines by improving the heat transfer from the stator. Hence, this research investigates key heat transfer parameters that limit convective and conductive heat transfer. The current density is interdependent on temperature and parameters governing heat transfer. Therefore, thermal analysis of electrical machines is important to design high current density electrical machines. This research starts by investigating the role air-cooled axial flux machines in the context of electric transportation. These are found to suffer from thermal limitations, forcing the propulsive power to be distributed among several wheels. The machine topology is found to play an important role in the heat transfer limits. The internal rotor topology suffers from heat transfer limits from the casing while the internal stator topology suffers from heat transfer in the rotor-stator gap. Addressing the latter is more challenging. This research does this by investigating a novel evaporative cooling mechanism to transport heat from the machine's internal stator to the outer rotor. A proof of concept was experimentally established and the challenges for adopting this mechanism to an electrical machine are investigated. The research focus is turned to direct oil-cooled machines. These do not suffer from the same thermal limits as they use an external radiator to expel heat. However, direct liquid cooled machines suffer from a non-uniform flow distribution, which affects the stator temperature distribution. To investigate this problem, an efficient thermo-fluid model was developed to predict the flow and temperature distribution in an oil-cooled stator. This was compared to CFD models and validated to within 6% of experimental results. The stator temperature distribution is improved by carefully controlling the flow distribution. The hot spot temperature is reduced by 13 K, doubling the insulation lifetime, or for the same hot spot temperature increasing the current density by 7%. The heat transfer coefficient an oil-cooled machine was measured by adapting the double layer thin film heat flux gauge technique. Correlations for the heat transfer coefficient on the pole piece surfaces are established and compared with analytical and CFD predictions. Finally the focus is turned to conductive heat transfer in concentrated windings. These are shown to suffer from a severe temperature gradient. Heat is transferred from one winding layer to the next and a hotspot is formed on the layer with the longest thermal path. The hotspot limits the current density of the machine. A lumped parameter thermal model was developed to predict the value and location of the hotspot in concentrated windings. To shorten the thermal path of the windings, a heat sink was interleaved between the windings. The new construction offers a reduction in hotspot temperature by up to 70 K. For the same maximum temperature the current density is increased by 30%. This thesis revisits flat windings and addresses their manufacturing challenges. Lastly, the relevance of thermal contact resistances is broadened to the general thermal design of electrical machines. This research shows that modeling the thermal resistance at the interface of concentric geometry by a constant parameter is an oversimplification. This was experimentally demonstrates to change with heat flux, contact pressure and material properties.

<p>In this thesis a hybrid electrical powertrain called the Four Quadrant Transducer (4QT) has been evaluated through different driving simulations, which later resulted in the manufacture of a prototype.</p><p>The simulation of a 12 metric ton distribution truck showed that the 4QT system can reduce the fuel consumption by approximately 30 % during the FTP75 drive cycle. The reduction in fuel consumption is due to a more optimal control of the combustion engine and regenerative braking of the vehicle.</p><p>The prototype 4QT has been down scaled from the distribution truck size used in the simulations to a size suitable for a medium sized passenger car. This was done to fit the test rig in the electric machine laboratory.</p><p>The prototype was tested in the test bench to analyse performances such as efficiency, losses and thermal behaviour. These factors were investigated using both analytical models and the finite element method and later by measurements. The measured results were according to expectations.</p> / <p>I denna doktorsavhandling presenteras ett nytt elhybridsystem för vägfordon benämnt fyrkvadrant omvandlare, "Four Quadrant Transducer (4QT)". Detta system har simulerats under körcykler som t ex FTP75 för att kunna bilda sig en uppfattning om bränsleförbrukningen för hybridsystemet och för att kunna dimensionera elmaskinerna till systemet. En elmaskinprototyp för hybridsystemet har konstruerats och provats i momentvåg.</p><p>Enligt utförda simuleringar blir besparingen i bränsleförbrukning ca 30% för en tolv tons distributionslastbil utrustad med en 100kW dieselmotor under körcykeln FTP75. Denna minskning av bränsleförbrukning kommer främst från en mera optimal kontroll av förbränningsmotorn samt regenerativ bromsning av fordonet.</p><p>Den konstruerade prototypen är avsedd för en medelstor bil. Anledningen till att prototypen inte byggdes i en storlek passande för distributionslastbilen var att prototypen skulle passa i testutrustningen i elmaskinlaboratoriet.</p><p>Prototypen provades i momentvåg för att undersöka verkningsgrad, förluster och termiska prestanda. Resultaten är enligt förväntningarna.</p>