Spelling suggestions: "subject:"drives"" "subject:"brives""
321 |
Tušírovací lis s pohybovými šrouby / Try-out press with motion screwsŠvoma, Jan Unknown Date (has links)
The aim of this thesis is a complex design of the spotting press with a nominal force of 500 kN, which is intended for mating of the both halves of pressing tool for the automotive industry. The press ram is fitted with a hydraulic mechanism which allows the upper clamping board to be tilted in range of 0° -180° and removed from the working space of the press along a profile track. The lower clamping board is a part of moving bolster, which is equipped with a mechanism for lifting and centring. The concept of motion screws is used to drive the ram. Motion screws are mounted in a multiple-part frame and driven by servomotors. The thesis contains background research of the issue, solutions of the main design nodes of the press including calculations, detailed 3D model of the device and partial drawing documentation.
|
322 |
Integrated Common And Differential Mode Filters With Active Damping For Active Front End Motor DrivesAcharya, Anirudh B 01 1900 (has links) (PDF)
IGBT based power converters acts as front end in the present day Adjustable Speed Drive (ASD). This offers many advantages and makes regenerative action possible. PWM rectifier operation produces electrically noisy DC bus on common mode basis. This results in higher ground current as compared to three phase diode bridge rectifier. Due to fast turn-ON and turn-OFF time of IGBT, the inverter output voltage dv/dt is high during switching transients and voltage waveform is rich in harmonics. As a result, in applications involving long cable the motor terminal voltage during the switching transient is as high as twice the applied voltage. This voltage stress reduces the life of insulation in motors. The high dv/dt output voltage applied at the motor terminal excites the parasitic capacitive coupling resulting in increased ground currents and causes Electric Discharge Machining (EDM) which reduces the life of motor bearings. The common mode voltage due to PWM rectifier and the inverter appear at the motor terminals exacerbating these problems.
The common mode voltage due to PWM inverter with PWM rectifier is analyzed. An integrated approach for filter design is proposed wherein the adverse effects due to common mode voltage of both AFE converter and the inverter is addressed. The proposed topology addresses the problems of common mode voltage, common mode current and voltage doubling due to ASD. The design procedure for proposed filter topology is discussed with experimental results that validate the effectiveness of the filter.
Inclusion of such higher order filter in the converter topology leads to problems such as resonance. Passive methods are investigated for damping the line resonance due to LCL filter and common mode resonance due to common mode filter. The need for active damping technique for resonance due to common mode filter is presented. State space based damping technique is proposed to effectively damp the resonance due to line filter and the common mode filter. Experimental results are presented that validate the effectiveness of active damping both on the line basis (differential mode) and line to ground basis (common mode) of the filter.
|
323 |
Řízení jednoúčelového obráběcího stroje / Control of special purpose machine toolPlocek, Jaroslav January 2015 (has links)
The master thesis treats the design of control system of special purpose machine tool. The first part analyzes and compares two possible variants of control system which use either a CNC control system Sinumerik or motion control system Simotion. Only the variant with the Simotion control system is subsequently examined in detail: its hardware configuration, the selection of components and partly also the software solution. The thesis further deals with the safety of the realized control system and of the whole machine. There are described general safety requirements of machinery based on harmonized European standards and their specific application in the design of safety functions and the safety circuits of solved machine tool.
|
324 |
Monitoring of age-relevant parameters in an integrated inverter system for electrical drives based on SiC-BJTsFrankeser, Sophia 16 November 2018 (has links)
The Silicon Carbide Bipolar Transistor is a device that is barely brought into real application so far. It features very low conduction losses and a high power density. The application is in some points different and unusual in comparison to the mainstream power semiconductors as IGBTs or MOSFETs. The Silicon Carbide Bipolar Transistor, the SiC-BJT, is a current driven device and the effort in driving is uncommonly high. As an outcome of the present work it can be said that it is more like a shift of requirements from the power semiconductor power unit to the driver stage. With consideration of all system losses, including driving losses, the final unoptimized COSIVU prototype inverter system gained an increase of efficiency of 40-60% in comparison to the IGBT-based reference system dependent on the applied load points.
In terms of reliability and possible failure modes, the SiC-BJT behaves differently from the mainstream devices. One result of the project is that the chips itself are quite robust but the packaging needs some improvements. Thermal impedance spectroscopy is a method for detecting possible deterioration in the cooling path of a device. A method for temperature estimation of the SiC-BJT during on-state will be presented in this work. The electronic hardware for thermal impedance spectroscopy has been developed to do the measurements in a non-laboratory setup in the inverter in real application. Furthermore, the hardware implementation was realized on a very small space for integration into an in-wheel motor inverter system. / Der Siliciumkarbid Bipolartransistor ist ein leistungselektronisches Bauelement, was bis heute kaum über Labor- und Forschungsprojekte hinaus anwendungsnah zum Einsatz kam. Er verfügt über sehr geringe Durchlassverluste und eine hohe Leistungsdichte. Seine Verwendung und Anwendung ist in mancher Hinsicht anders und unüblich im Vergleich zu den etablierten leistungselektronischen Bauelementen wie IGBT und MOSFET. Der Siliciumkarbid Bipolartransistor, also der SiC-BJT, ist ein stromgesteuertes Bauteil, weswegen der Aufwand für die Treiber sehr hoch ist. Die praktische Arbeit im Rahmen des Forschungsprojektes „COSIVU“ mit den SiC-BJTs in Verbindung mit dem fertigen integrierten Invertersystem hat unter anderem gezeigt, dass es mehr eine Verschiebung der Anforderungen von der Leistungselektronik hin zu den Treibern für die Leistungselektronik ist. Unter Betrachtung der Verluste des gesamten Systems, einschließlich der Motor-, Treiber- und Steuerverluste, hat das fertige Prototyp-Invertersystem, welches durchaus noch Potential zur Optimierung besaß, eine deutliche Verbesserung des Wirkungsgrades erreicht. Gegenüber dem auf IGBT basierenden Referenz-Invertersystem, hat das COSIVU Invertersystem eine Verbesserung des Wirkungsgrades um 40-60 % erreicht.
Eine Erkenntnis aus dem Forschungsprojekt in Bezug auf Zuverlässigkeit und mögliche Fehler und Defekte ist, dass der Chip selbst zwar ziemlich robust ist, aber dass die Gehäuse-, Aufbau- und Verbindungstechnik angepasst und verbessert werden sollte. Thermische Impedanzspektroskopie ist eine Methode um Verschlechterungen im Kühlpfad eines leistungselektronischen Halbleiters zu erkennen, was ein Kriterium für die Alterung des Bauteils ist. Eine Methode zur Bestimmung der Sperrschichttemperatur von SiC-BJTs während des normalen Durchlassbetriebes wird in dieser Arbeit vorgestellt. Die Platine für die thermische Impedanzspektroskopie wurde entwickelt, um die Messung in einem laborfernen Aufbau in einer echten Inverteranwendung durchzuführen. Zudem wurden die Platinenaufbauten auf sehr kleiner Fläche realisiert. Die Integration musste nämlich sehr kompakt gestaltet werden, da es sich um ein „in-wheel“ Motor-Inverter-System handelt, was zum größten Teil innerhalb eines Fahrzeugrades untergebracht ist.
|
325 |
Einsatz der Mechanismensoftware MechDev in der LehreHüsing, Mathias, Knobloch, Thomas, Brünjes, Vincent, Corves, Burkhard 20 June 2024 (has links)
Die am Institut für Getriebetechnik, Maschinendynamik und Robotik (IGMR) der RWTH
Aachen entstandene Software Mechanism Developer (MechDev) wurde mit dem Ziel
entwickelt, ein umfangreiches aber dennoch intuitiv zu bedienendes Tool zur Analyse und
Synthese ebener Mechanismen für Industrie, Lehre und Forschung zur Verfügung zu
stellen. [1,2]
Algorithmik, Softwareentwurf und aktueller Funktionsumfang der Software wurden in der
Vergangenheit bereits ausgiebig vorgestellt [3,4]. Mit dem anstehenden Release der
Software soll diese auch in den Lehrealltag des IGMR integriert werden. Zu diesem Zweck
müssen die Inhalte der Veranstaltungen Elektromechanische Antriebstechnik und
Bewegungstechnik auf die Software und deren Funktionen angepasst werden. Bis zuletzt
wurde in beiden Veranstaltungen das Tool GeoGebra [5] zum einen für Visualisierungen
von Sachverhalten in der Vorlesung genutzt, zum anderen dessen Verwendung den
Studierenden in Laborveranstaltungen vermittelt, um eigenständig Problemstellungen der
Getriebetechnik damit zu bearbeiten.
In diesem Beitrag sollen erste Ideen zum Einsatz der Software MechDev in der Lehre am
IGMR vorgestellt werden. Beispielhaft soll eine passende Übungsaufgabe gezeigt werden,
sowie deren Bearbeitung mit MechDev. Weiterhin werden zusätzliche Funktionen
abgeleitet, die zukünftig für die Nutzung der Software in der Lehre implementiert werden
sollen. / The Software Mechanism Developer (MechDev), which was developed at the Institute of
Mechanism Theory, Machine Dynamics and Robotics (IGMR) at RWTH Aachen
University, was developed with the aim of providing a comprehensive yet intuitive tool for
analysing and synthesising planar mechanisms for industry, teaching and research. [1,2]
The algorithms, software design and current functional scope of the software have already
been extensively presented in the past [3,4]. With the upcoming release of the software, it
is also to be integrated into everyday teaching at the IGMR. To this end, the content of the
Electromechanical Drive Technology and Motion Technology courses must be adapted to
the software and its functions. Until recently, the GeoGebra [5] tool was used in both
courses to visualise facts in the lecture, and students were also taught how to use it in
laboratory courses in order to work independently on transmission technology problems.
This article will present initial ideas for using the MechDev software in teaching at the
IGMR. A suitable exercise will be shown as an example, as well as how it can be worked
on with MechDev. Furthermore, additional functions will be derived that are to be
implemented in the future for the use of the software in teaching.
|
326 |
<b>OPTIMIZATION STRATEGIES OF A PARAMETRIC PRODUCT DESIGN </b><b>FOR A CIRCULAR ECONOMY WITH APPLICATION TO AN </b><b>ELECTRIC TRACTION MOTOR</b>Jesús Pérez-Cardona (17501118) 01 December 2023 (has links)
<p dir="ltr">In our daily lives, we rely on a multitude of discrete products to meet our needs. Traditional product design approaches have primarily focused on economic and technical aspects, often overlooking the pressing environmental and social challenges facing society. Recognizing the limitations of our ecological systems to cope with the waste generated by our current industrial processes, there is a growing need to anticipate the potential consequences of product design across technical, economic, environmental, and social dimensions to pave the way for a sustainable future. One promising strategy within this context is the integration of sustainability principles into optimization-based design models that consider a product's entire life cycle. While there have been previous efforts to optimize product life cycles, a comprehensive exploration of optimization-based design methods with a focus on multiple objectives for discrete products is essential. This dissertation explores the integration of sustainability principles with optimization-based design by taking the electric traction motor used in electric vehicles as a case study. This complex and environmentally significant technology is ideal for investigating the tradeoffs and benefits of incorporating sustainability objectives into the design process.</p><p dir="ltr">The key tasks undertaken in this study are as follows:</p><ul><li>Development of a parametric design and optimization framework for a surface-mounted permanent magnet synchronous motor. In this task, a special emphasis is placed on reducing reliance on materials with a high supply risk, such as rare earth elements.</li><li>Creation of a parametric life cycle assessment model that combines life cycle assessment and optimization-based design to minimize a single-score environmental impact. This model offers insights into the environmental performance of product design and underscores the importance of minimizing environmental impact throughout a product's life cycle.</li><li>Integration of a life cycle costing model, incorporating techno-economic assessment and total cost of ownership perspectives, into the parametric life cycle assessment and optimization-based design models. This model is used to minimize levelized production and driving costs, shedding light on the trade-offs within this family of cost metrics and the optimization of manufacturing systems for motor production.</li><li>Proposal of a circular economy model/algorithm to assess the advantages of integrating the circular economy paradigm during the early design phase. All the mentioned objective functions are considered to study the impacts of applying the circular economy paradigm.</li></ul><p dir="ltr">The contributions of this research can be summarized as follows:</p><ul><li>Utilized a diverse array of analytical methodologies to parameterize the design process of a motor, incorporating the integration of Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) models, as well as the incorporation of disassembly planning for informed decision-making in the early stages of design.</li><li>Proposed a generalized objective function denoted as the Supply Risk-equivalent (SR-eq.), aimed at mitigating the risks associated with the dependency on critical materials in product manufacturing.</li><li>Introduced a novel approach for visualizing non-dominated solutions within a multi-objective framework, with experimentation conducted on up to six distinct objectives.</li><li>Substantiated the significance of decarbonizing the electric grid while maintaining competitive cost structures, the importance of advancing non-destructive evaluation (NDE) procedures for assessing the condition of end-of-life (EoL) subassemblies, and optimizing the collection rate of EoL motors.</li></ul><p dir="ltr">Demonstrated that the optimization of technical metrics as surrogate indicators for economic and environmental performance does not necessarily yield designs that are concurrently optimal in economic and environmental terms.</p>
|
327 |
Distributed Algorithms for Multi-robot AutonomyZehui Lu (18953791) 02 July 2024 (has links)
<p dir="ltr">Autonomous robots can perform dangerous and tedious tasks, eliminating the need for human involvement. To deploy an autonomous robot in the field, a typical planning and control hierarchy is used, consisting of a high-level planner, a mid-level motion planner, and a low-level tracking controller. In applications such as simultaneous localization and mapping, package delivery, logistics, and surveillance, a group of autonomous robots can be more efficient and resilient than a single robot. However, deploying a multi-robot team by directly aggregating each robot's planning hierarchy into a larger, centralized hierarchy faces challenges related to scalability, resilience, and real-time computation. Distributed algorithms offer a promising solution for introducing effective coordination within a network of robots, addressing these issues. This thesis explores the application of distributed algorithms in multi-robot systems, focusing on several essential components required to enable distributed multi-robot coordination, both in general terms and for specific applications.</p>
|
328 |
Robustní řízení synchronního stroje s permanentními magnety a spínaným tokem / Fault-Tolerant Control of a Flux-switching Permanent Magnet Synchronous MachineAboelhassan, Mustafa Osman Elrayah January 2013 (has links)
Je jasné, že nejúspěšnější konstrukce zahrnuje postup vícefázového řízení, ve kterém každá fáze může být považována za samostatný modul. Provoz kterékoliv z jednotek musí mít minimální vliv na ostatní, a to tak, že v případě selhání jedné jednotky ostatní mohou být v provozu neovlivněny. Modulární řešení vyžaduje minimální elektrické, magnetické a tepelné ovlivnění mezi fázemi řízení (měniče). Synchronní stroje s pulzním tokem a permanentními magnety se jeví jako atraktivní typ stroje, jejíž přednostmi jsou vysoký kroutící moment, jednoduchá a robustní konstrukce rotoru a skutečnost, že permanentní magnety i cívky jsou umístěny společně na statoru. FS-PMSM jsou poměrně nové typy střídavého stroje stator-permanentní magnet, které představují významné přednosti na rozdíl od konvenčních rotorů - velký kroutící moment, vysoký točivý moment, v podstatě sinusové zpětné EMF křivky, zároveň kompaktní a robustní konstrukce díky umístění magnetů a vinutí kotvy na statoru. Srovnání výsledků mezi FS-PMSM a klasickými motory na povrchu upevněnými PM (SPM) se stejnými parametry ukazuje, že FS-PMSM vykazuje větší vzduchové mezery hustoty toku, vyšší točivý moment na ztráty v mědi, ale také vyšší pulzaci díky reluktančnímu momentu. Pro stroje buzené permanentními magnety se jedná o tradiční rozpor mezi požadavkem na vysoký kroutící moment pod základní rychlostí (oblast konstantního momentu) a provozem nad základní rychlostí (oblast konstantního výkonu), zejména pro aplikace v hybridních vozidlech. Je předložena nová topologie synchronního stroje s permanentními magnety a spínaným tokem odolného proti poruchám, která je schopná provozu během vinutí naprázdno a zkratovaného vinutí i poruchách měniče. Schéma je založeno na dvojitě vinutém motoru napájeném ze dvou oddělených vektorově řízených napěťových zdrojů. Vinutí jsou uspořádána takovým způsobem, aby tvořila dvě nezávislé a oddělené sady. Simulace a experimentální výzkum zpřesní výkon během obou scénářů jak za normálního provozu, tak za poruch včetně zkratových závad a ukáží robustnost pohonu za těchto podmínek. Tato práce byla publikována v deseti konferenčních příspěvcích, dvou časopisech a knižní kapitole, kde byly představeny jak topologie pohonu a aplikovaná řídící schémata, tak analýzy jeho schopnosti odolávat poruchám.
|
329 |
Capacitorless Power Electronics Converters Using Integrated Planar Electro-MagneticsHaitham M Kanakri (18928150) 03 September 2024 (has links)
<p dir="ltr">The short lifespan of capacitors in power electronics converters is a significant challenge. These capacitors, often electrolytic, are vital for voltage smoothing and frequency filtering. However, their susceptibility to heat, ripple current, and aging can lead to premature faults. This can cause issues like output voltage instability and short circuits, ultimately resulting in catastrophic failure and system shutdown. Capacitors are responsible for 30% of power electronics failures.</p><p dir="ltr">To tackle this challenge, scientists, researchers, and engineers are exploring various approaches detailed in technical literature. These include exploring alternative capacitor technologies, implementing active and passive cooling solutions, and developing advanced monitoring techniques to predict and prevent failures. However, these solutions often come with drawbacks such as increased complexity, reduced efficiency, or higher upfront costs. Additionally, research in material science is ongoing to develop corrosion-resistant capacitors, but such devices are not readily available.</p><p dir="ltr">This dissertation presents a capacitorless solution for dc-dc and dc-ac converters. The proposed solution involves harnessing parasitic elements and integrating them as intrinsic components in power converter technology. This approach holds the promise of enhancing power electronics reliability ratings, thereby facilitating breakthroughs in electric vehicles, compact power processing units, and renewable energy systems. The central scientific premise of this proposal is that the capacitance requirement in a power converter can be met by deliberately augmenting parasitic components.</p><p dir="ltr">Our research hypothesis that incorporating high dielectric material-based thin-films, fabricated using nanotechnology, into planar magnetics will enable the development of a family of capacitorless electronic converters that do not rely on discrete capacitors. This innovative approach represents a departure from the traditional power converter schemes employed in industry.</p><p dir="ltr">The first family of converters introduces a novel capacitorless solid-state power filter (SSPF) for single-phase dc-ac converters. The proposed configuration, comprising a planar transformer and an H-bridge converter operating at high frequency, generates sinusoidal ac voltage without relying on capacitors. Another innovative dc-ac inverter design is the twelve step six-level inverter, which does not incorporate capacitors in its structure.</p><p dir="ltr">The second family of capacitorless topologies consists of non-isolated dc-dc converters, namely the buck converter and the buck-boost converter. These converters utilize alternative materials with high dielectric constants, such as calcium copper titanate (CCTO), to intentionally enhance specific parasitic components, notably inter capacitance. This innovative approach reduces reliance on external discrete capacitors and facilitates the development of highly reliable converters.</p><p dir="ltr">The study also includes detailed discussions on the necessary design specifications for these parasitic capacitors. Furthermore, comprehensive finite element analysis solutions and detailed circuit models are provided. A design example is presented to demonstrate the practical application of the proposed concept in electric vehicle (EV) low voltage side dc-dc power converters used to supply EVs low voltage loads.</p>
|
Page generated in 0.0406 seconds