The master’s thesis introduces various types of electric motors. Overall, it is divided into 6 chapters, which the first deals with special type of electric motors, namely: permanent magnet DC motor with coreless winding, piezoelectric motor and three phase induction motor with solid rotor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The second part of thesis deals with perspective types of motors, namely: single phase induction motor and reluctance motor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The third chapter deals with analysis parameters of single phase induction motor. The analysis is performed on a borrowed motor from ATAS company by measurement and verification using simulation program Ansys Maxwell. The fourth part discusses the possibilities of increasing the effectiveness of borrowed electric motor. The following is chapter five, which deals with increasing the efficiency of the motor by changing metal sheets. Results are verified by simulations with Ansys Maxwell and measurements on sample of electric motor. The last part presents electric motor design with new selected electric sheets with lower specific losses, but also with lower magnetic induction.

L'autonomie moyenne des voitures électriques commercialisées actuellement reste limitée par rapport aux véhicules thermiques. Pour pallier ce problème, la capacité de la batterie peut être augmentée ou bien la charge peut être facilitée en réduisant le temps de charge et ceci en augmentant la puissance de charge.L'infrastructure de charge rapide de type DC étant encore limitée, un progrès considérable consiste à embarquer le chargeur dans le véhicule en réutilisant tout, ou une partie de l'électronique de puissance déjà disponible pour propulser le véhicule. Le chargeur est alors nommé chargeur intégré.Au cours des dernières années, plusieurs chargeurs intégrés ont été proposés, mais peu d'entre eux ont été industrialisés vue qu'ils présentent des inconvénients que l'on cherchera à surmonter ou réduire.Dans le cadre de cette thèse notre objectif principal est donc de concevoir une nouvelle topologie de convertisseur permettant la charge de la batterie à moindre coût.Plusieurs idées permettant l'innovation sont proposées et une solution répondant au mieux au cahier de charges est retenue. Cette topologie est étudiée en détails (contrôle, dimensionnement, harmoniques, CEM, etc.). Finalement un prototype est réalisé pour valider le concept proposé. / To date, the range autonomy of most electric vehicles is still lower than conventional fuel based vehicles and charging times are significantly longer. To overcome this problem, battery capacity could be increased but more importantly high power fast charging should be accessible everywhere.The widespread deployment of public DC fast charging stations is still difficult to achieve. So, in order to have a better spreading of the charge spots and a better coverage, it is also necessary for the vehicle to be charged from an on-board charger that could be plugged into three-phase AC power outlets.Furthermore, because the battery is charged only when the car is parked -except for regeneration at braking-, using the on-board traction system components to form an integrated charging device is possible. This kind of topology is called an integrated charger which allows designing a charger small enough to be embedded in a vehicle at an affordable cost.Several non-isolated on-board integrated charging topologies are proposed in this thesis and the one that best meets some predefined specifications is selected. This topology is studied in details and validated by simulation software. A laboratory prototype is also built to verify the performance of this multi-purpose traction/charger converter.

In this investigation, a single phase fluid is used to study the coupling between natural convection heat transfer within an enclosure and forced convection through computer covering case to cool the electronic chip. Two working fluids are used (water and air) within a rectangular enclosure and the air flow through the computer case is created by an exhaust fan installed at the back of the computer case. The optimum enclosure size configuration that keeps a maximum temperature of the heat source at a safe temperature level (85℃) is determined. The cooling system is tested for varying values of applied power in the range of 15−40𝑊. The study is based on both numerical models and experimental observations. The numerical work was developed using the commercial software (ANSYS-Icepak) to simulate the flow and temperature fields for the desktop computer and the cooling system. The numerical simulation has the same physical geometry as those used in the experimental investigations. The experimental work was aimed to gather the details for temperature field and use them in the validation of the numerical prediction. The results showed that, the cavity size variations influence both the heat transfer process and the maximum temperature. Furthermore, the experimental results ii compared favourably with those obtained numerically, where the maximum deviation in terms of the maximum system temperature, is within 3.5%. Moreover, it is seen that using water as the working fluid within the enclosure is capable of keeping the maximum temperature under 77℃ for a heat source of 40𝑊, which is below the recommended electronic chips temperature of not exceeding 85℃. As a result, the noise and vibration level is reduced. In addition, the proposed cooling system saved about 65% of the CPU fan power.

A three-phase power supply is a de facto standard when selecting a power supply to homes in Sweden, regardless of whether it is flat with low energy consumption or a house with electric heating. This project aims to determine the advantages and disadvantages of using a three-phase supply compared to a single-phase supply to homes. This thesis starts with a historical literature review to find answers to why a three-phase supply is a de facto standard in Sweden. Single-phase and threephase supplies to homes were compared by creating an electrical circuit model that used actual household load profiles. The load profiles were taken from a study that measured the power consumption in 400 Swedish homes. Two houses and four flats from that study was selected as input data to the circuit model. Each house was modelled as both single-phase and three-phase. The power losses in the supply conductors from the power meter to the homes distribution panel was calculated. The selectivity between the main fuses and Miniature Circuit Breakers (MCB) was also investigated by comparing the let-through energy of MCBs and pre-arcing energy of fuses. The results from the historical review indicate that one of the reasons that three-phase supplies became the de facto standard is that Sweden implemented a new tariff system. All the customers with low power consumption were placed in the 16 A main fuse category, and the network fee was the same for single-phase and threephase the previous system had a higher price for three-phase. The power losses in single-phase supplies and three-phase supplies with a similar total conductor area were compared. The results that a three-phase supply had lower losses in all the cases, even though the loads were mostly 230 V loads and not perfectly balanced between the phases. A three-phase supply is preferable over a single-phase supply if the home has high energy consumption. However, a single-phase supply might be a good option if the home has a low to moderate energy consumption. The reason for this is that the losses are only slightly higher in absolute terms, and a single-phase supply enables a higher main fuse rating for the supplies total cross-section, and it is, therefore, easier to coordinate the downstream protective devices / Att använda sig av trefasmatningar till bostäder är en de facto-standard i Sverige, oavsett om det är en lägenhet eller en eluppvärmd villa så väljs nästan alltid en trefastmatning. I det här projeket undersöks anledningar till att trefasmatningar är de facto-standarden i svenska bostäder. Målet med projektet är även att undersöka fördelar och nackdelar med trefasmatning och enfasmatning jämfört med varandra vid matning av bostäder Rapporten inleds med en litteratur studie vars syfte var att ta reda på historiska händelser som kan lett till att trefas blev standarden för matning av bostäder. För att jämföra trefasmatning och enfasmatning av bostäder så användes en elkrets av bostäder som använde effektförbrukning från en studie som har samlat in mätvärden för förbrukningen i 400 svenska hushåll. Två villor och fyra lägenheter undersöktes. Elkretsen användes sedan för att beräkna förluster i kablaget mellan elmätaren och elcentralen, varje bostad undersöktes både med enfasmatning och trefasmatning. Selektiviteten mellan huvudsäkringar och dvärgbrytare på utgående grupper undersöktes för felförlopp och överlast. Litteraturstudien visade tecken på att införandet av säkringstariffen 1963 kan ha gjort så att trefasmatningar blev de facto-standarden i Sverige. När säkringstariffen implementerades placerades samtliga kunder med lågförbrukning in 16 A säkrings kategorin, oavsett om de hade ett trefasabonnemang eller enfasabonnemang. Vilket gjorde att nätavgiften var densamma för enfas och trefas, tidigare var det billigare med enfas. Resultaten från undersökningen av ledningsförluster visade att trefasmatningen gav lägre förluster, även fast de mesta av lasterna var enfaslaster och inte perfekt balanserade. Resultaten visar att en trefasmatning är ett bättre val om bostaden har en hög energiförbrukning. Resultaten visar även att en enfasmatning kan vara ett bättre val om bostaden har låg energiförbrukning eftersom den totala mängden energi som går förlorad är låg i båda fallen. Eftersom en enfasmatning gör det möjligt att ha en högre huvudsäkring än en trefasmatning med samma totala ledararea, vilket gör att det är lättare att koordinera huvudsäkringen gruppledningarnas dvärgbrytare.

<p>Flow-Accelerated Corrosion (FAC) is a pipe wall thinning mechanism affecting carbon steel piping systems in power generation plants. Mass transfer is the rate limiting factor, even though chemistry and materials determine the overall potential for FAC. Different localized thinning rates in back to back elbow configurations between the first and second elbow have been noted at nuclear power plants, and this difference depends on the length of pipe between the elbows, flow conditions, and the configuration of the back to back elbows (e.g. S, C, or out of plane). In this thesis, mass transfer measurements in back to back elbows arranged in an out of plane configuration under single and annular two-phase flow conditions are presented.</p> <p>The mass transfer measurements were performed using a wall dissolving technique with bend sections cast from gypsum. The diffusivity of gypsum in water is similar to the diffusivity of iron from the magnetite layer of carbon steel pipe in water, thus providing analogous mass transfer conditions to FAC in power generation plants. The wall dissolution of gypsum allows the surface roughness to develop due to the flow. The mass transfer is determined by passing water through the gypsum test sections in a flow loop system. The test sections are then sectioned into two halves to expose the worn surface. The surface topology is measured using a three dimensional laser scanner. The wear progression of the surface with time provides local mass transfer rates, locations of high mass transfer and local surface roughness.</p> <p>The single-phase flow experiments were performed at a Reynolds number of 70,000 for different lengths of pipe (0, 1, 2 and 5 pipe diameters) between the elbows. The mass transfer results show regions of higher mass transfer in the second elbow in comparison to the first el­­bow. The maximum mass transfer rate in the second elbow decreases when the length of the pipe between the elbows was increased from 0 to 5 pipe diameters. Surface features corresponding to flow streaks on the second elbow surface indicated swirling flow, and its strength decreases with increasing separation distance between the elbows. The surface roughness was found to be higher in the regions of high mass transfer and decreases with increasing elbow separation distance.</p> <p>The effect of air and water superficial velocities on the mass transfer for the bends with a separation distance of 0 pipe diameters was measured under two-phase air-water annular flow. In addition, the effect of separation distance of 0, 1 and 5 pipe diameters in length between the elbows was studied for one annular flow condition. The highest mass transfer was found on the outer wall of the first elbow for all cases. The maximum mass transfer in the second elbow was found to be approximately 60 percent of the maximum value in the first elbow, and was not affected significantly when the elbow separation distance was increased from 0 to 1 and 5 pipe diameters. The separation distance between the elbows did not affect the maximum mass transfer on the outer wall of the first elbow. The mass transfer increased with an increase in either the water or air superficial velocity, with the air velocity having a greater effect. The mass transfer enhancement factor relative to that in a straight pipe only increases significantly with increasing air superficial velocity. The roughness development in the pipe was modest, but increases significantly in the high mass transfer region of the first and second elbow.</p> / Master of Applied Science (MASc)

AC and DC impedances of switching power converters are used for the stability analysis of modern power electronics systems at three-phase AC and single-phase DC interfaces. Therefore, a small-signal characterization algorithm for switching power converter, which is based on FFT, will be presented and explained. The presented extraction algorithm is general and can be used to obtain other small-signal transfer functions of arbitrary power converter switching simulation models. Furthermore, FFT algorithm is improved by using cross power spectral density functions for identification, resulting in an algorithm, which is more noise immune. Both small-signal identification algorithms are validated in simulations, and CPSD algorithm is used in experimental measurement procedure. Several wide bandwidth injection signals, among which are chirp, multi-tone, pulse and white noise, are compared and theoretically analyzed. Several hardware examples are included in the analysis. The second part of the dissertation will focus on the modeling of small-signal input dq admittance of multi-pulse diode rectifiers, providing comparison between well-known averaged value models (AVMs), parametric averaged value models (PAVM), the switching simulation model and hardware measurements. Analytical expressions for all four admittances present in the dq matrix are derived and analyzed in depth, revealing the accuracy range of the averaged models. Furthermore, a hardware set-up is built, measured and modeled, showing that the switching simulation model captures nonlinear sideband effects accurately. In the end, a multi-pulse diode rectifier feeding a constant power load is analyzed with modified AVM and through detailed simulations of switching model, proving effectiveness of the proposed modifications. The third part describes implementation and design of a single-phase multi-level single-phase shunt current injection converter based on cascaded H-bridge topology. Special attention is given toward the selection of inductors and capacitors, trying to optimize the selected component values and fully utilize operating range of the converter. The proposed control is extensively treated, including inner current, outer voltage loop and voltage balancing loops. The designed converter is constructed and integrated with measurement system, providing experimental verification. The proposed multi-level single-phase converter is a natural solution for single-phase shunt current injection with the following properties: modular design, capacitor energy distribution, reactive element minimization, higher equivalent switching frequency, capability to inject higher frequency signals, suitable to perturb higher voltage power systems and capable of generating cleaner injection signals. Finally, a modular interleaved single-phase series voltage injection converter, consisting of multiple paralleled H-bridges is designed and presented. The decoupling control is proposed to regulate ac injection voltage, providing robust and reliable strategy for series voltage injection. The designed converter is simulated using detailed switching simulation model and excellent agreement between theory and simulation results are obtained. The presented control analysis treats different loads, examining robustness of the circuit to load variations. Simulation model and hardware prototype results verify the effectiveness of the proposed wide-bandwidth identification of small-signal dq impedances via single-phase injections. / Ph. D.

Recently, due to the increasing adoption of distributed energy resource (DER) technologies including battery energy storage (BES) and electric vehicle (EV) systems, bidirectional power converters are becoming more popular. These converters are broadly utilized as interface devices and provide a bidirectional power flow in applications where the primary power supply can both supply and receive energy. A dc capacitor, called the dc-link, is an important component of such bidirectional converters. For a wide range of applications, the converter is required to control the dc-link voltage. Commonly, a proportional-integrating (PI) controller is used by the dc capacitor voltage controller to generate a set-point for the inner current controller. This approach tightly regulates the dc-link voltage to a given value. The research presented in this dissertation shows that such an approach compromises the stability margins of the converter for reverse power flow and weak grid conditions. It is shown that by allowing a small variation of dc capacitor voltage in proportion to the amount of power flowing through the converter, the stability and robustness margins are improved. This approach also simplifies the design process and can be applied to both dc/dc and dc/ac (single-phase and three-phase) converters. Moreover, it grants an inherent power sharing capability when multiple converters share the same dc-link terminals; removing the need to a communication link between parallel converters. The proposed controller is equipped with a current limiting mechanism to protect the converter during low-voltage/over-current transients. Detailed analyses, simulations, comparisons, and experimental results are included to illustrate the effectiveness of the proposed control approach. To mathematically establish the properties of the proposed method in a single-phase dc/ac application, this dissertation also derives a new and systematic modeling approach for a grid-connected bidirectional single-phase inverter controlled in stationary frame. Implementing the control system in the stationary frame has advantages over rotating frame. However, the combination of dc and ac state variables and nonlinearities make its stability analysis challenging. In the proposed model, an imaginary subsystem is properly generated and augmented to allow a full transformation to a synchronous rotating frame. The proposed modeling strategy is modular and has a closed form which facilitates further extensions. It is successfully used to demonstrate enhanced stability margins of the proposed controller.

The DC-side floating capacitors in the floating power modules of power converters are subject to high voltage fluctuation, due to the presence of reactive harmonic components. Utilizing passive capacitors, as done in traditional methods, helps reduce the DC-bus voltage ripple but makes the system bulky. An active capacitor can be integrated with the floating H-bridge power modules to remove the effect of the ripple powers on the DC bus. The auxiliary circuit, which is much smaller in size compared to an equivalent passive capacitor, helps increase the power density of the system. This work focuses on the analysis of power components, and the extension of the active capacitor to the Perturbation Injection Unit (PIU), in which the DC side is highly distorted by multiple harmonic components. A control scheme is proposed to compensate for these multiple harmonics and balance the DC-link voltage in the active capacitor. Also, an equivalent DC-bus impedance model is introduced, which is more accurate than that in existing works. Simulation studies and evaluation of the design have verified the effectiveness of the active capacitor solution. / Single-phase power converters have been widely used in many applications such as electric vehicles, photovoltaic (PV) systems, and grid integration. Due to their popular application, there is a need to reduce the sizes and volumes while still maintaining good performances of the systems. One of the most effective methods, which is a subject in many research works, is to replace the bulky passive capacitor bank in a system by an active capacitor. The active capacitor is designed to absorb the ripple components in the DC side of the converters, which results in a constant DC-link voltage. In comparison to the passive capacitor solution, the active capacitor is much smaller in size but can give a better DC-bus ripple performance. Therefore, the active capacitor has become an attractive solution for the single-phase converters. The active capacitor for the traditional rectifier, where the DC side is directly connected to a load, has been intensively investigated in the past decade. However, there is limited research regarding the active capacitor for rectifiers with floating H-bridge power modules. This work extends the application of the active capacitor to the Perturbation Injection Unit (PIU), which is a grid-connected single-phase rectifier with floating H-bridge power modules. The selection of a suitable active capacitor for the PIU is based on the evaluation of various active capacitor banks. Limits in existing control schemes, which prevent the extension of the active capacitor to the PIU, are thoroughly studied. An effective voltage-mode control scheme is then proposed for the selected active capacitor, which makes it an attractive solution for the PIU. Moreover, limits of the DC-bus impedance analysis using traditional assumptions in existing works are investigated, and an improved DC-bus impedance model is proposed. Based on the operation conditions of the PIU and the proposed impedance model, the active capacitor's components can be properly designed, and improved configurations in terms of the equivalent impedance can be analyzed. Simulation results, as well as the design and evaluation of the active capacitor, demonstrate great improvements in terms of volume and weight over the traditional passive capacitor bank.

Made available in DSpace on 2016-04-26T20:27:03Z (GMT). No. of bitstreams: 1 Vanessa Rahal Canado.pdf: 1017567 bytes, checksum: e2882c38d8ba54122acb3ac62e62d51c (MD5) Previous issue date: 2008-04-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of this dissertation is to construct the essential rules connected to the levy ( regras matrizes de incidência tributária ) of the COFINS tax, based on provisions contained under specific laws which govern the four main collection regimes of said contribution: cumulative , noncumulative , single-phase taxation and tax substitution . Based on the provisions of Complementary Law n. 70/91 and of Law n. 9.718/98, we have constructed, besides the generic rule of levy of the COFINS in the cumulative regime , other 6 (six) specific rules, referred to herein as differentiated treatments in the cumulative regime . Essentially, from the provisions under Law n. 10.833/03, besides the generic rule of levy of the COFINS in the non-cumulative regime , we identified 12 (twelve) more specific rules of levy, also referred to as "differentiated treatments in the non-cumulative regime." In turn, with regard to the tax substitution COFINS regime, solely the manufacturers and wholesale sellers of cigarettes remained, according to the provisions under Article 3 of Complementary Law n. 70/91 and Article 29 of Law n. 10.865/04. Finally, based on the provisions of Laws n. 9.718/98 (Articles 4, 5 and 6), n. 10.147/00, n. 10.485/02, n. 10.560/02 and n. 10.833/03 (Article 49), we could identify 12 (twelve) rules of the levy of the COFINS in the so-called single-phase taxation regime. Besides the aforementioned legislation, specific provisions under Provisional Measure n. 2.158-35/01 and Laws n. 10.684/03, n. 10.865/04, n. 10.925/04, n. 11.051/04 and 11.196/05 were also necessary for the analysis and description of the rules of levy of the COFINS which were constructed herein / Esta dissertação tem como principal objetivo construir as normas tributárias de incidência (regras-matrizes de incidência tributária) da COFINS, a partir de enunciados prescritivos contidos em leis específicas que regem os quatro principais regimes de apuração da referida contribuição: cumulativo , não-cumulativo , de incidência monofásica e de substituição tributária . Tomando-se por base os enunciados da Lei Complementar n. 70/91 e da Lei n. 9.718/98, foi possível construirmos, além da regra-matriz de incidência tributária genérica , para apuração da COFINS no regime cumulativo , outras 6 (seis) regras específicas, que denominamos de tratamentos diferenciados no regime cumulativo . A partir, essencialmente, dos enunciados da Lei n. 10.833/03, além da regra de incidência genérica da COFINS no regime não-cumulativo , pudemos construir mais 12 (doze) normas específicas de incidência, que denominamos, também, de tratamentos diferenciados no regime nãocumulativo . No regime de substituição tributária , restaram apenas os fabricantes e comerciantes atacadistas de cigarros, conforme disposições do artigo 3º, da Lei Complementar n. 70/91 e do artigo 29, da Lei n. 10.865/04. Por fim, descrevendo acerca dos enunciados das Leis n. 9.718/98 (artigos 4º, 5º e 6º), n. 10.147/00, n. 10.485/02, n. 10.560/02 e n. 10.833/03 (artigo 49), pudemos construir 12 (doze) regras-matrizes de incidência tributária da COFINS no regime denominado de incidência monofásica . Além das leis acima citadas, também prescrições específicas da Medida Provisória n. 2.158-35/01 e das Leis n. 10.684/03, n. 10.865/04, n. 10.925/04, n. 11.051/04 e n. 11.196/05 foram necessárias para a delimitação das normas construídas

Este trabalho trata de um estudo teórico sobre o MMPI. Inicialmente, apre-sentamos um levantamento bibliográfico sobre o MMPI evidenciando os seus aspectos construtivos, seu funcionamento, suas características operacionais e suas possíveis aplicações. Em seguida, elaboramos um modelo físico fundamentado nas teorias do Motor de Indução Duplamente Alimentado (MIDA) e do Motor de Histerese (MH), o qual agrega as principais características operacionais do MMPI e reproduz o processo dinâmico de inscrição de pólos na periferia do rotor. A partir deste modelo físico propomos um modelo matemático, baseado na teoria dos circuitos magneticamente acoplados, constituído pelo equacionamento do MIDA, do MH e das fontes de alimentação do estator e do rotor. Deduzimos teoricamente todos os parâmetros necessários para a simulação computacional. Executamos a sua simulação computacional no software Matlab/SimulinkTM, cujos resultados ilustram o comportamento dinâmico das suas tensões, correntes, fluxos e mecânica. Comparando-se os resultados obtidos na simulação computacional com testes laboratoriais executados pelo CE-PEL, concluímos que o modelo matemático proposto e os parâmetros deduzidos podem ser considerados validados. Finalizando, sugerimos um motor monofásico de pólos lisos a imãs permanentes como uma alternativa mais simples do ponto de vista construtivo, porém com características operacionais semelhantes às do MMPI. / This work deals with a theoretical study on Written-PoleTM single-phase motor. Initially, we present the results from the bibliographical research on the Written-PoleTM motor, evidencing its constructional features, operation process, operational characteristics and some possible applications. Afterwards, we elaborate a physical model based in the theories of the doubly fed induction motor and the hysteresis motor, which incorporates the operational characteristic of Written-PoleTM motor and reproduces the written-pole dynamic process. Starting from this physical model we propose a mathematical model, based on the theory of the magnetically coupled circuits, constituted by the set of differential equations deduced from the doubly fed induction motor, the hysteresis motor and the stator and rotor voltage sources. We deduced theoretically all the computational simulation necessary parameters. We perform its computational simulation in the software Matlab/SimulinkTM, whose results illustrate the dynamic behavior of its voltages, currents, fluxes, torques and speed. Comparing the results obtained from the computational simulation with the CEPEL\'s test results, we concluded that the proposed mathematical model and the deduced parameters can be considered validated. Finally, we suggest a permanent-magnet smooth-pole single-phase motor as an alternative to Written-PoleTM motor. This alternative, even being simpler from the constructional point-of-view, presents operational characteristics similar to the Written-PoleTM single-phase motor.