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The electric car is a technically efficient driveline, although it is demanding in terms of the primary energy source. Most trips are below 50 km and the mean power required for maintaining speed is quite low, but the system has to be able to both provide long range and high maximum power for acceleration. By separating power and energy handling in a hybrid driveline, the primary energy source, e.g. a battery can be optimised for specific energy (decreasing costs and material usage). Kinetic energy storage in the form of flywheels can handle the short, high power bursts of acceleration and decceleration with high efficiency. This thesis focuses on the design and construction of flywheels in which an electric machine and a low-loss magnetic suspension are considered an integral part of the composite shell, in an effort to increase specific energy. A method of numerically optimising shrink-fitted composite shells was developed and implemented in software, based on a plane stress assumption, with a grid search optimiser. A composite shell was designed, analysed numerically and constructed, with an integrated permanent magnet synchronous machine. Passive axial lift bearings were optimised, analysed numerically for losses and lift force, and verified with experiments. Active radial electromagnets optimised for high stiffness per ohmic loss were built and analysed in terms of force and stiffness, both numerically and experimentally. Electronics and a high-speed measurement system were designed to drive the magnetic bearings and the electric machine. The control of these systems were implemented in an FPGA, and a notch-filter was designed to suppress eigenfrequencies to achieve levitation of the rotor. The spin-down losses of the flywheel in vacuum were found to be 1.7 W/Wh, evaluated at 1000 rpm. A novel switched reluctance machine concept was developed for hollow cylinder flywheels. This class of flywheels are shaft-less, in an effort to avoid the shaft-to-rim connection. A small-scale prototype was built and verified to correspond well to analytical and numerical models, by indirect measurement of the inductance through a system identification method.

A hollow cylinder flywheel rotor with a novel outer rotor switched reluctance machine (SRM) mounted on the interior rim is presented, with measurements, numerical analysis and analytical models. Practical experiences from the construction process are also discussed. The flywheel rotor does not have a shaft and spokes and is predicted to store 181 Wh / kg at ultimate tensile strength (UTS) according to simulations. The novel SRM is an axial flux machine, chosen due to its robustness and tolerance for high strain. The computed maximum tip speed of the motor at UTS is 1050 m / s . A small-scale proof-of-concept electric machine prototype has been constructed, and the machine inductance has been estimated from measurements of voltage and current and compared against results from analytical models and finite element analysis (FEA). The prototype measurements were used to simulate operation during maximal speed for a comparison towards other high-speed electric machines, in terms of tip speed and power. The mechanical design of the flywheel was performed with an analytical formulation assuming planar stress in concentric shells of orthotropic (unidirectionally circumferentially wound) carbon composites. The analytical approach was verified with 3D FEA in terms of stress and strain.

A complete passive magnetic bearing system, consisting in a Permanent Magnet radial bearing and a Superconductive Magnetic Bearing has been simulated and constructed. The forces in both types of magnetic bearings are not linear. The non-linear behavior has been implemented in a FEM model and compared with linear models. A spin down test has been conducted to the built system and the Eigen frequencies have been recorded. The Eigen frequencies calculated with and without the non-linear behavior implemented in the model are very similar.

Webben är en framgångssaga. Men vilka tekniska egenskaper gör den framgångsrik?Dr. Roy Fielding identifierade dess stora fördelar och vilka arkitektoniskarestriktioner som främjar dessa. REpresentational State Transfer, ellerREST, är en arkitektonisk stil som samlar dessa restriktioner under en akronym.REST kan användas för att ge webbens positiva egenskaper till webbservicessom konsumeras av automatiserade klienter. Uppdraget har varit att implementeraett Application Programming Interface (API) på ett befintligt system föravtalshantering. API:et ska vara RESTful. Vad detta egentligen innebär verkarinte helt solklart. En stor del av arbetet har legat i att studera Fieldings avhandlingoch reda ut begreppen. Det centrala i REST är det enhetliga interfacet, sominnebär att system, oberoende av varandra ska kunna förstå de meddelandensom hanteras. Det utvecklade systemet har utvärderats mot definitionen avREST och systemet saknar den essentiella delen Hypertext As The Engine OfApplication State (HATEOAS). Denna del är också vad som verkar vara denmest missförstådda, eller till och med helt ignorerade delen av REST. HATEOASinnebär att servern genom länkar, dynamiskt serverar klienten med de vägarklienten kan navigera API:et. Detta leder till att ny funktionalitet kan läggas tillutan att skapa inkompatibilitet med klienten. Klienten kan välja att ignorera länkarmed relationer den inte känner igen. För att REST ska vara användbart såmåste klienten förstå relationerna i API:ets länkar och representationen av dessdata. The World Wide Web is a success. But, what technical properties made it whatit is today? Dr. Roy Fielding identified the web´s great advantages and a set ofarchitectural restrictions to guard the advantages. REpresentational State Transfer,or REST, is an architectural style gathering these restrictions under oneacronym. REST can be used to give the web´s properties to web services to beconsumed by automated clients. The mission has been to implement an ApplicationProgramming Interface (API) on top of a system for contract handling.The API should be RESTful. What RESTful actually means seems unclear. Themajor part of the work has been to study Fieldings dissertation, sorting out thecharacteristics. The central part of REST, is the uniform interface. It allows intermediarynodes to understand the meaning of a message without knowinganything else about the sender. The system developed has been evaluatedagainst Fieldings definition of REST, still the system lacks Hypertext As TheEngine Of Application State (HATEOAS). This part seems to be the mostwidely misunderstood part of REST, often completely ignored. HATEOASgives the server the power of steering the client through the API, by always providinglinks to the available steps. This leads to the ability to add functionalityto the API without breaking the client. The client can just ignore the links that itdoes not know how to handle. For REST to be useful by automated clients, theclient needs to understand the link relations and the data representations of theAPI.

A Sliding Mode Control System for a Bidirectional DCDC Converter was designed and a low voltage prototype was constructed. The control system based its decisions solely on the latest available measurements, which improves performance when changing operative quadrant, since no memory needs reinitializing (such as for PI and state prediction methods). A boost control philosophy was presented, based on a current source approximation. The control was found to be stable without steady-state errors when the variance of the input/output dynamics was high. The target application for the DCDC Converter is an EV (Electric Vehicle) with a flywheel driveline, which puts additional requirements of the converter. Among these are current and voltage control, bidirectionality, and a broad input voltage range. Simulations were performed in Simulink prior to physical implementation, proving functionality of the proposed control system. The physical implementation of the control was done on a digital signal processor with code compiled from C. A median filter was designed to increase measurement efficiency for the current sensors which had shot-like noise distortions.

Branding has today a central role in marketing. Branding has in theory been focused on brands of large corporations and consumer goods. The situation of branding in this study differs from the traditional view. In this case is branding studied from the perspective of a small company offering services for an industrial market. The key concepts of the study are identity, image and positioning. The aim is to find how the concept applies on a small company brand, but also how the company will benefit from the brand development. The study is limited to brands that already exist, excluding building of a completely new brand. The branding strategies considered means further development of a present brand with consideration to the existing customer relationships. The existing customer group has to be considered since the brand is already established. The research approach is explorative and qualitative. The study is conducted by a case study at Infologigruppen, an IT-consultant firm located in Norrbotten. Infologigruppen is representative for the brand situation described above, a small local company offering industrial services. The research method is interviews from both identity and image perspective. The results indicates that the theoretical benefits and advantages from branding can be applied only to a limited extent in this case, the brand is of most benefit in the communication with new customers. Functional positioning seems to have a great influence on the composition of identity and image. Further, brand development is in this case not limited by existing customer relationship in any significant way. Validerat; 20101217 (root)