This diploma thesis is focused on an analysis and design of an AC machines windings. In the theoretical part of the thesis, differences between single-layer and double-layer windings are explained. Next, the properties of a stator winding of synchronous machines are described. Finally, the winding factor is determined by means of a standard calculation method and by means of a new progressive calculation method, too. In the experimental part of this thesis, the stator winding of a high-speed synchronous generator excited by permanent magnets on the rotor is designed. This generator is driven by a steam turbine.

This diploma thesis deals with distribution stress and strain of sheets metal of rotor packet and in critical locations of supporting bars of synchronous generator. These variants are calculated and one another comparison of analytic calculation results, numeric calculation of 2D model and numeric calculation of 3D model in three vriants ( with bars of rectangle section, circular section, with upper radius). The calculation include influence of thermal expansion, centrifugal force, interference of the packet on the shaft and prestress in the axial direction of bolt. To creation of geometric model and numerical calculation is used program ANSYS 11.

This diploma thesis focuses on composite pipes production by winding of composite fibres soaked in resin binder and feeding with additional third type material simultaneously. It also describes the production machine FWMS180 and all of its additional devices necessary for the composites production by filament winding. The production process of composite pipes on the production machine FWMS180 is described in this paper as well as detailed description of the winding method. Furthermore, the technological bend and vibration tests procedures conducted on pipes of different material composition are discussed with related results and comparison. The thesis proves that presence of the third type material in composite pipes structure has different influence depending on observed and evaluated property.

I detta examensarbete har en studie utförts för att ta fram och jämföra metoder att modellera krökta vangstycken av stål med komplexa geometrier i programmet Tekla Structures. Avgränsningen för studien har varit att jämföra två metoder: Metod 1 använder verktygen Complex Polybeam Creation i kombination med Surface Generation Between Polybeams i Tekla, och Metod 2 trappverktyget Spiral Staircase. En vindeltrappa från projektet Patienten och Princeton, Sankt Eriks ögonsjukhus i Hagastaden, har använts för att testa de komplexa geometrier som denna vindeltrappa medför. Utifrån detta har Tutorials av de båda metoderna skapats, för att läsaren enkelt ska kunna följa och genomföra samma steg. Resultatet av examensarbetet är att båda metoderna fungerar för modellering, beroende på vilken typ av geometri som skapas. Efter modellering med trappverktyget Spiral Staircase gick det inte att ta fram korrekta tillverkningsritningar av de horisontella plåtarna, till skillnad från Metod 1. Slutsatsen av studien är att vid enbart snabb modellering av cirkulära geometrier samt framtagning av tillverkningsritningar för vertikala krökta plåtar, kan med fördel Metod 2 användas. Däremot vid framtagning av tillverkningsritningar av komplexa och icke cirkulära geometrier lämpar sig Metod 1 bäst. / In this thesis, a study has been conducted to develop and compare methods of modeling curved stringer made of steel with complex geometries in the Tekla Structures program. The delimitation of the study has been to compare two methods: Method 1 uses the Complex Polybeam Creation tools in combination with Surface Generation Between Polybeams in Tekla, and Method 2 uses the tool Spiral Staircase. A spiral staircase from the project Patienten and Princeton, Sankt Eriks Eye Hospital in Hagastaden, Stockholm, has been used to test the complex geometries that this spiral staircase entails. Based on this, Tutorials of the two methods have been created, so that the reader can easily follow and implement the same steps. The result of this thesis is that both methods work for modeling, depending on the type of geometry that is created. After modeling with the tool Spiral Staircase, correct manufacturing drawings of the horizontal plates could not be obtained, unlike Method 1. The conclusion of the study is that with only rapid modeling of circular geometries as well as production of manufacturing drawings for vertical curved plates, Method 2 can be used with advantage. However, in the production of manufacturing drawings of complex and non-circular geometries, Method 1 is best suited.

Electric propulsion in the heavy truck industry require knowledge in certain new areas involved in electric machine manufacturing. One of these new manufacturing steps is copper bending for production of stator windings. This thesis aimed to look at whether finite element simulations can be used in gathering experience to improve an existing stator design. Existing winding scheme is modeled, and simplified cases of different bending steps are simulated using finite element method. The result shows the critical areas where the largest stress and strain occurs in the existing design, giving input of how the bending affects the copper wire as well as the isolation layer of the wire, to improve future bending scheme designs. / Transportindustrin för tunga fordon står inför ett teknikskifte, klassisk förbränningsteknik ersätts av elektrisk drift. Denna tekniska utveckling innebär nya produkter i tillverkningen, vilket kräver kunskap kring processer för statorlindning med koppartråd. Detta arbete har ämnat titta på huruvida simulering med finita element metod kan användas för att erhålla kunskap kring böjningens påverkan på koppartråd och dess isoleringsskikt. Det har ingått geometrisk modellering av ett befintligt böjningsmönster, finita element simulering av förenklade geometrier för att utvärdera kopparens samt isoleringsskiktets spänningar och töjning vid böjning, resultatet visar vart de största deformationerna är samt vilka böjningar som kan vara kritiska, vilket ger information för möjliga designförbättringar till kommande lindningsscheman.

The filament-winding process produces quality consistent composite parts for many industries. Filament winding allows for consistent quality parts by automating the winding process. A recent development of filament winding is the Lotus process. The Lotus process reverses conventional filament winding by leaving the mandrel stationary and winding composite fiber around the mandrel. The automated Lotus filament-winding machine is controlled by four-axis control manipulating the Lotus ring around a fixed mandrel. This allows Lotus filament winding to wind parts that do not have a linear axis. Lotus filament winding is in its early stages of development. As a second step in the development of Lotus filament winding a method of automatic part-to-machine manipulation has been developed. Parts wound on the new automatic-manipulated Lotus machine have comparable quality and appearance to those made by conventional winding.

Knowledge of the end winding inductance of electrical machines is decisive for calculating their operating performance. In this article, two different approaches to analytically calculate the stator end winding inductance of large induction machines are discussed. The first method is based on the exact replication of the 3D conductor geometry using serially connected straight filaments, where the inductances are calculated by solving Neumann’s integral. In the second method, the end winding flux is resolved into components excited by the axial and circumferential end winding magnetomotive force, resulting in a far simpler geometrical model. In both cases, end face effects are taken into account by adopting the method of images. The analytical approaches are compared to the known analytical calculation method proposed by Alger [1]. In addition, the stator end winding inductance is computed by means of 3D finite-element analysis. Using experimental validation, it is shown that both the analytical and numerical results reasonably correlate with removed rotor inductance measurements taken for several induction machines with different rated powers and frame sizes, if the permeability of the laminated core is taken into consideration.

In recent years, there is a clear trend toward increasing the demand for electric power in high-power applications. High-power converters are making major impacts on these high-power applications. Recent breakthroughs in Silicon Carbide (SiC) materials and fabrication techniques have led to the development of high-voltage, high-frequency power devices, which are at the heart of high-power converters. SiC metal-oxide semiconductor field-effect transistors (MOSFETs) have advantages over silicon (Si) devices due to their higher breakdown voltage, higher thermal capability, and lower on-state resistance. However, their fast switching frequency and high blocking voltage bring challenges to the gate-drive circuit design. The gate driver of SiC-MOSFETs requires a power supply that provides a high-voltage, high-density design, a low input-output capacitance (CI/O) transformer design, good voltage regulation, as well as good resilience to faults to enable safe and fast operation. In this thesis, a power supply that supplies multiple gate drivers for 10 kV SiC MOSFETs is presented. A transformer design approach with a single turn at the primary side is proposed. A 20 kV insulation is achieved by the primary HV cable insulation across a toroid transformer core. The CI/O is designed less than 2 pF to mitigate the Common-Mode (CM) noise. A circuit topology analysis is performed and the inductor/capacitor/capacitor/inductor (LCCL) – inductor/capacitor (LC) circuit is selected. This circuit allows Zero-Voltage Switching (ZVS) at full operation range. A Resonant-Current-Bus (RCB) is built at the transformer primary side to achieve load-independence. / Master of Science / Wide-bandgap semiconductor devices have attracted widespread attention due to their superior performance compared to their silicon devices counterpart. To utilize its full benefits, this thesis presents a complete design and optimization of a gate-drive power supply that supplies multiple gate drivers for high-voltage, high-speed semiconductor devices. Four objectives, including high density at high voltage, good noise mitigation, fair voltage regulation, resilience to faults have been achieved. During the design procedure, different topology candidates are introduced and compared, after which a resonant topology is selected. The wide-bandgap semiconductor devices are utilized to reduce the size and losses. Hardware assembly is shown and experimental testing results are provided in the end to verify the design.

Im Rahmen des Bundesxzellenzclusters MERGE EXC 1075 an der TU Chemnitz erfolgte die Entwicklung einer neuartigen großserientauglichen Technologie zur Herstellung faserverstärkter Thermoplastbauteile. Für die Demonstration der Technologie wurde eine Pilotanlage realisiert, die zum Ablegen des Thermoplasttapes über eine Verlegeeinheit – einen sog. Tapelegekopf – verfügt. Mit Abschluss des Legeprozesses wird das Halbzeug, das aus einer angebremsten Spule abgezogen wird, abgeschnitten und der Prozess wird von neuem begonnen. Für das Schneiden des Materials haben Voruntersuchungen gezeigt, dass konturierte Klingen erforderlich sind, um ein Verlaufen des Bandes zu vermeiden. Darüber hinaus hat sich als zweckmäßig erwiesen eine zusätzliche Fixierung vorzunehmen. Dies verbessert die Schnittqualität und Zuverlässigkeit des Systems. Aufgrund enger Bauraumrestriktionen wurde entschieden die Schneidbewegung und das Fixieren zwangläufig synchronisiert auf einen Antrieb zurück zu führen. Hierfür wurden zwei ungleichmäßige Rastgetriebe synthetisiert, ausgelegt sowie in weiteren Entwicklungsstufen auskonstruiert, gefertigt und getestet. Mit der Inbetriebnahme des Gesamtanlagensystems erfolgte ebenfalls der Funktionsnachweis dieses mechanisch zwangläufigen Schneidsystems, das im Rahmen des Vortrags vorgestellt wird. Diese Arbeiten entstanden im Rahmen des Bundesexzellenzclusters EXC 1075 „Technologiefusion für multifunktionale Leichtbaustrukturen“ und wurde von der Deutschen Forschungsgemeinschaft gefördert. Die Autoren danken für die finanzielle Unterstützung.

In den letzten 20 Jahren näherte sich der einst nur für die Luft- und Raumfahrt entwickelte kohlenstofffaserverstärkter Kunststoff (CFK) mehr und mehr der industriellen Umsetzung in anderen Bereichen an. Die CFK-Halbzeuge und -Bauteile sind nun auch preislich in der Lage, unter Anwendung angepasster Fertigungsverfahren breiter eingesetzt zu werden. Der Fokus dieser Arbeit richtet sich exemplarisch auf die kosten- und energieeffiziente Herstellung von schnell laufenden CFK-Verbundwalzen und soll aufzeigen, dass Kostenersparnisse über Leane Fertigungsmethoden auch in der FKV-Industrie von großem Vorteil sind. Somit liefert diese Dissertationsschrift einen beispielgebenden Beitrag für den Durchbruch von Faserverbund-werkstoffen im industriellen Bereich. Darüber hinaus werden durch Prozessoptimierung Alternativen aufgezeigt, qualitativ hochwertigere und gleichsam kosteneffiziente Bauteile herzustellen.