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  • 1.
    Abdulhadi, Sami
    Karlstad University, Faculty of Technology and Science.
    ARM i inbyggt system: med prototyp2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Embedded systems has become more and more common in today's society. The embedded systems are included in almost everything today, from various vehicles to children's toys.

    Today's technology means that yesterday's solutions can be realised on a fraction of the area. More and more become surface mounted with smaller and more complex circuits. This is not always an advantage for the developers when assembling and soldering prototype circuit boards become a more difficult and/or an expensive process.

    The goal is to create an embedded system with an ARM-processor. The system will consist of USB-OTG, ethernet, various memory like FRAM and microSD and a display with touchscreen for user interface. The project includes everything from choice of components to test and verification with program code.

    The time was too short to include all the parts that was planned. The result of the project was a prototype card and two small program sequences, one that blinks the two light diodes on the card and one that writes a picture on the display.

    This embedded system is intended for evaluating ARM-processors by Mikrododakt AB.

  • 2.
    Ahlquist, Ulrika
    Karlstad University, Division for Information Technology.
    Trådlöst elektriskt lås2007Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med examensarbetet är att göra en trådlös version av det elektriska lås som tillverkas av Electec System AB.

    För att göra ett trådlöst elektriskt lås måste ett batteri monteras i låset. Batteriet måste hållas uppladdat hela tiden för att kunna driva motorn och ge strömförsörjning till elektroniken i låset. Alla signaler mellan låset och styrenheten ska dessutom överföras trådlöst istället för med kabel. Signalerna måste kodas innan sändning så att ingen obehörig kan läsa signalen och sedan öppna dörren.

    Det svåraste i ett trådlöst elektriskt lås är att överföra effekt från dörrkarmen till låset eftersom utrymmet är begränsat och avståndet mellan låsblecket i karmen och låset i dörren kan uppgå till 10 mm. För att överföra effekt från dörrkarmen till låset konstruerades en transformator. Förlusterna i transformatorn ökar kraftigt då luftgapet ökas.

    Det visar sig att motor och övriga kretsar kan drivas med ett avstånd mellan kärnorna på upp till 7 mm. Luftgapet kan sannolikt ökas när andra transformatorkärnor används. Dessa fanns dock inte tillgängliga under examensarbetets gång på grund av lång leveranstid. I jämförelse med överföring av effekt är problemet att koda och överföra signaler mellan styrenheten och låset enklare och kan lösas med hjälp av färdiga kretsar.

  • 3.
    Andersson, Göran
    Karlstad University, Division for Information Technology.
    Synchronized Clock2007Independent thesis Basic level (professional degree), 10 points / 15 hpStudent thesis
    Abstract [en]

    For this project I was planning to construct a clock that could be synchronized with an external source. The clock should be able to keep the time between synchronizations as these may be sparse. It also needed to be able to store the current time in a memory and keep a register of stored times. The current time and the register must be viewable by the user and the clock must also have the ability to count down the last five seconds prior to a minute selected by the user. I have performed this work at home with my own equipments.

    As an external source for the synchronization I have chosen the DCF-77 clock signal broadcasted from Germany. To receive this signal I used a cheap AM receiver built specifically for this purpose. For the actual clock I used a PIC microcontroller which I programmed in C. The chip had all I needed including an oscillator and a RAM memory. I also connected a 3x16 character LCD display to the clock as well as 4 1-pole buttons for the user interface.

    The program is built upon an interrupt routine that with help of an internal timer is set to execute once every hundreds of a second. During this interrupt routine all other functions are executed. These functions include a DCF decoder, an internal clock to keep the time, an LCD driver and a user interface.

    I have managed to read the clock signal from the receiver but due to interferences from the computer I used to program the PIC chip, I have not been able to get any good reception close to the computer. Apart from this setback the clock works as it should and it meets all other criteria.

  • 4.
    Andersson, Johan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Jansson, Ulf
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Analys av solcellsanläggningar påverkan på elnätet2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

    Examensarbetet handlar om vilka effekter mikroproduktion i form av solcellsenheter har och kommer att ha på Karlstads elnät. Via flera mätserier har här sammanställts vad som händer med elkvaliteten i nätet och vilka krav som ställs på elnätsbolag och framtida mikroproducenter. Genom bred teoretisk kunskap och praktiskt arbete med ett antal dataprogram har denna rapport arbetats fram och sammanställts. Vid ett flertal tillfällen har upphovsmännen bakom denna rapport gett sig ut i fält för att på plats ta del utav dagens former av solkraft samt också iakttagit arbetet bakom och inför elkvalitetsundersökningar.Syftet har i grunden varit att ge kunskap inför ökande volymer av mikroproduktion och att förbereda för framtida förändringar och ombyggnationer i det lokala elnätet. Arbetet har resulterat i en tydlig bild av att dagens elnät har goda möjligheter att möta en ökning av producenter med låga produktionsnivåer. Det har konstaterats att försiktighet bör tas vid inkoppling av anläggningar vad gäller enfas och trefas. Eftersträvansvärt är att använda trefasinkoppling för att undvika snedbelastningar i nätet.

  • 5.
    Andersson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Johansson, Andreas
    Karlstad University, Faculty of Technology and Science.
    Tillämpning av effektstabilisering i PLC2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the degree project is to make a digital realization of a stabilizer for oscillations in the active power from a hydropower synchronous generator, connected to a power network.

    The implementation is supposed to be done in a PLC which already handles part of the excitation system.

    The power stabilization is achieved by sending a counteracting reference signal to the excitation system which controls the generator’s output power. This counteracting signal can be achieved in several ways.

    Two existing models, standardized by IEEE, for power system stabilizing will be examined, PSS1A and PSS2B.

    A Simulink-model of a distribution net with a generator is constructed to test the stabilizers.

    To perform a digital implementation a discrete transformation of one continuous model is done. This discrete model is also tested to verify the function in comparison to the continuous one.

    The discrete model is reorganized in a form possible to implement in the PLC.

    Comparison between the simulated and the implemented model is made by measurement.

  • 6.
    Arntsson, Timmy
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Elnätet och dess anpassning för elektriska fordon: En studie av hur ett lokalnät påverkas av ett ökat antal elektriska fordon2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The availability of non-renewable fuels is decreasing and therefore the prices of both petrol and diesel has increased in recent years. As a result more and more chooses to invest in cars powered by alternative fuels and the focus has long been on electric vehicles. However, this means greater weight on utility companies around the world which now have to adjust to a higher demand. The purpose of this study is to investigate how a local network are affected by electric car chargers and be able to describe the degree to which a low-voltage can be loaded with electric car chargers for commercial and private use, in order to provide recommendations for the future dimension of the local networks. Few studies have been conducted regarding electric cars from a network and supply perspective, but have instead been focused on energy storage in the actual vehicle. Therefore, this study has been processed with an electricity grid perspective.

    The intent of the study has been answered by both a measurement and several simulations. The study is based on Karlstad’s local electrical network and the commercial charging station Tesla in Våxnäs, Karlstad. The parameters of power quality for which this study has taken into account are load of the transformers, load loss, power factor, efficiency, voltage levels, voltage drop and asymmetry.

    The methodological conditions have led to a result that can be used as a basis for an expansion of electric cars, big or small. The measurement was of great support to get an overall view of how the characteristics of a charging session appeared and how the quality parameters were affected during high as well as low power charging. Limitations within the simulation program have led to the calculations to carry out in a more extreme scenario when it comes to the load. A result since the simulation time for constant power was minimum one hour.

    Based on the measurement and simulations of the charging station for commercial use is dimensioned well to cope with the current use of electric vehicle charging. More municipalities should follow Karlstad’s example for the development of commercial charging stations. In the countryside great problems occurred, especially with voltage drop at an increased use of home chargers for electric cars. The same problems emerged in the city part of the network. The study also showed serious problems with asymmetry in the city. The report concluded, therefore, several recommendations for the future dimension of local networks for private homes, for example that the local network should be divided into multiple trails.

  • 7.
    Bellström, Peter
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Information Systems and Project Management.
    Kop, Christian
    Institute for Applied Informatics, Alpen-Adria Universität Klagenfurt.
    Vöhringer, Jürgen
    econob GmbH.
    Semi-Automatic Schema Pre-Integration in the Integration of Modeling Language Independent Behavioral Schemata2012In: ThinkMind: eKNOW 2012, The Fourth International Conference on Information, Process, and Knowledge Management / [ed] Mauri, J.L & Lorenz, P., IARIA Conference , 2012, p. 12-17Conference paper (Refereed)
    Abstract [en]

    In this paper, we address schema pre-integration in the integration of modeling language independent behavioral schemata. In doing so, we propose and present a set of tasks that should be carried out not only to improve and clarify the meaning of a schema, but also to facilitate the resulting time consuming and error-prone phases in the integration process. Due to the complexity of schema pre-integration, domain experts and repositories (e.g. ontologies) are still important sources of knowledge and should therefore be involved during the whole integration process. As its main contribution, the paper offers new tasks to perform in the schema pre-integration process as well as an adjusted and enriched work of previously presented tasks for schema pre-integration.

  • 8.
    Brocker, David
    et al.
    Karlstad University, Faculty of Technology and Science.
    Hallberg, Erik
    Karlstad University, Faculty of Technology and Science.
    Hertzman, Andreas
    Karlstad University, Faculty of Technology and Science.
    Electrical track system: Utveckling av ett nytt system, innefattande elektrisk golvlist och uttag, som medger flytt av de traditionellt fasta vägguttagen2006Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    This degree project concludes the Innovation and Design Engineering programme at Karlstad University. The project was carried out by David Brocker, Erik Hallberg and Andreas Hertzman during the spring of 2006 and corresponded to 15 weeks of work per student. Assigner was Martin Larsson at Arexor and instructor at Karlstad University was Monica Jakobsson.

    Arexor has a patent to a construction of an electrical skirting board with moveable wall sockets, called Electrical Track System. The lowest parts of the interior walls along the floor are today almost always covered by a conventional skirting board. Arexors patented product replaces that with the possibility to move and increase the number of wall sockets by choice along an electrical skirting board. Conventional wall sockets are limited due to fixed positions and are not transferable. It causes a problem when the number of fixed wall sockets controls the possibilities and not the users demand.

    The assignment commissioned by Arexor to the students was to improve and develop the Electrical Track System because the patent did not fulfil the requirements for CE certification. The project results were to be used by Arexor as the basic data when the product was tested by ETL SEMKO.

    The objective of the project was to present directions for production to a functioning prototype of the Electrical Track System, within the estimated time period. The prototype was to be shown at the exhibition for degree projects at Karlstad University in May 2006. The objective also included to create a product brochure and a display case.

    The development method were divided into five phases: preparation phase, research phase, idea generating phase, conception development phase and concretisation phase. They were carried out linear up to the conception development phase. Then iteration between the research phase, idea generating phase, conception development phase was repeated until satisfied result was achieved.

    The result included a number of functioning prototypes, a display case, a product brochure, CAD drawings, renderings and this academic report. The prototypes were manufactured by Modellteknik in Eskilstuna, Sweden.

    Parts of the result cannot be presented due to that the solutions was not, at the time, protected by the patent. Arexor announced in the end of the project that they would apply for a new patent that included our solutions. Because of that these solutions could not be shown in public. Some parts in the report therefore refer to secrecy.

  • 9.
    Cederberg, Petter
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School.
    Kan e-tjänster förenklas och bli mer motiverande med gamification och öppna data?: En kvalitativ studie2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inför sommaren 2015 var 40 % av alla bygglovsansökningar som skickades in till Karlstads kommun antingen felaktiga eller ofullständiga och det leder till stora förseningar på tiden det tar från inskickad ansökan till att beslut fattas från kommunens handläggare. Denna kandidatuppsats syftar till att undersöka om det med hjälp av gamification och öppna data går att förenkla e-tjänster och på vilket sätt, med ansökan av byggnadslov som exempel på en kommunal e-tjänst på hos Karlstads kommun.

    Gamification innebär att applicera spelmekanismer eller spelupplevelser i icke spelrelaterade sammanhang för att öka motivationen och engagemanget hos användarna. Öppna data är när

    data som tidigare inte varit tillgänglig blir disponibel för allmänheten att använda, återanvända och distribuera utan andra förbehåll än källangivelse.

    Kandidatuppsatsen har genomförts i form av litteraturgenomgång som bas och kvalitativa intervjuer med personer som arbetar med gamification, öppna data eller kommunala e-tjänster.

    Slutsatserna av undersökningen visar att e-tjänster kan behöva bli mer självförklarande och enklare så att fler medborgare klarar av att använda e-tjänsten. Genom att applicera enklare spelmekanismer som passar till kontexten hos en e-tjänst och informationen som går att få ut genom öppna data är det möjligt att förenkla e-tjänster och göra de mer motiverande för slutanvändaren.

    Gamification kan göra e-tjänster enklare och mer motiverande med till exempel:  Ge användaren mer feedback

     Sparfunktion så att användaren får möjlighet att spara sina framsteg

     Förloppsindikator så att användaren kan följa hur långt i processen den kommit

    Öppna data kan göra e-tjänster enklare och mer motiverande med till exempel:

     Geografisk data

     Korslänkning av olika öppna data

  • 10.
    Danielsson, Christoffer
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Konstruktion av modulär turbinstyrning i hydroelektrisk kraftproduktion2012Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of this degree project is to design a modular turbine control unit for applications in hydroelectric power production. Normally, the control units are custom made for each new customer, this method is however quite expensive and time-consuming. The local conditions (such as turbine type or number of generators) can vary greatly between hydro power plants, and the unit must therefore be designed to be as compatible and allround as possible.

    The control unit is required to manage the control of the wicket gates of the turbine and, where it is needed, the propeller angle of a Kaplan turbine. The unit should be designed to work as a stand-alone unit, as well as a part of a network of control units. The construction has to be safe. Powerful forces are in motionwhen dealing with hydroelectric power production, thus necessary arrangements are required to be made to guarantee personal and material safety.

    The overall goal is to construct a cheap, versatile product for water turbine controlthat can be used under as many dierent conditions as possible.

    The project is split into three different parts, Design, Hydraulic Construction and Control Program. A lot of the construction and design work follows the same pattern: A set of specifications and requirements are defined. Different solutions and designs are then constructed and evaluated. After some work, a drawing(or program) will emerge. The project also includes dimensioning and choosing thecomponents that are used.

    The project resulted in blueprints for a turbine control unit concept. The design concept features a system that is compatible with PID controllers, it has the necessary functions to control the water turbine, and it is built to guarantee mechanical as well as personal safety. The result is presented as a number of mechanical and hydraulic CAD drawings, and a control program made for use in a PLC. A list of all the components needed, and an economical evaluation is also presented as a part of the result.

  • 11.
    Danielsson, Mattias
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Parallelldrift av multipla Stirlingmotordrivna asynkronmaskiner med gemensam frekvensomriktare2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Cleanergy konceptutvecklar stirling baserade solkraftsparker som inkluderar många asynkronmaskiner. Arbetet ämnar att undersöka om parallelldrift av två eller flera asynkronmaskiner är möjlig för att i slutändan skapa kostnadsbesparing för större solkraftsparker i storleksordning över 5MW.

    Parallell drift av två stycken asynkronmaskiner undersöks i detta arbete då de drivs av en gemensam frekvensomriktare. Det långsiktiga målet är att köra flera asynkronmaskiner under samma frekvensomriktare för att få en kostnadsbesparing, där det första steget är att verifiera koncept och funktion för två asynkronmaskiner.

    Asynkronmaskinens rotoraxel sitter sammanlänkad med en stirlingmotor i en enhet som drivs av solkraft (Sunbox) eller bio- och naturgas (Gasbox). Sunbox- och Gasboxenhetens uppstart körs i motorläge av asynkronmaskinen. Asynkronmaskinen går efter det över i generatordrift då stirlingmotorn producerar vridmoment på rotoraxeln, vid avstängning går asynkronmaskinen åter över i motordrift innan stopp.

    Arbetets huvudsyfte och största fokus är därmed att bekräfta funktionen av dessa effektövergångar och drift vid dubbla maskiner under samma frekvensomriktare.

    Kompletterande mätningar görs under funktionstestesterna som sammanställs i den slutgiltiga analysen av konceptets verifiering.

    Det kan bekräftas att ABB:s frekvensomriktare i produktserie ”ACS800” som användes i detta arbete med styrmetod DTC (eng. Direct torque control) och skalär drift hanterade dubbla maskiner. I detta fall är DTC att rekommendera för bäst styrning. Ett första steg mot konceptverifiering för denna uppställning, ytterligare utredningar för slutgiltig verifiering återstår. 

  • 12.
    Ekblom, Johan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Stenberg, Mikael
    Karlstad University, Faculty of Technology and Science.
    Utredning av effektförbrukningen på Älvenäs industrihotell Pescator AB2007Independent thesis Basic level (professional degree), 10 points / 15 hpStudent thesis
    Abstract [en]

    This assignment is a study of the unknown power consumption at “Älvenäs industrihotell Pescator AB”. They’ve recently changed their power supply and since the change, they have started to record measurements of the power usage. It came to their attention that a large part of the power consumption wasn’t recorded. During our research of the building we first did a visual inspection and then we started to measure the current in different places. We’ve found that a large part of the unrecorded power was lighting.

  • 13. Engström, Fredrik
    et al.
    Lindahl, Tind
    Avbrottsövervakning i elnät2013Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
  • 14.
    Erik, Jansson
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Erik, Tideström
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Analys och utvärdering av elektrokemiska kondensatorer för bruk i lättviktshybridfordon2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Precer Group erbjuder tekniska lösningar för produktion av el genom förbränning av olika typer av fasta bränslen. Tekniken är anpassningsbar och kan bland annat användas som återladdningskälla i olika typer av hybridfordon. Precer Group håller just nu på att ta fram ett konceptfordon i form av en lättviktshybrid som är tänkt att drivas genom att en sådan förbränning driver en generator som laddar upp ett energilagringssystem. En elmotor strömförsörjs sedan av detta energilagringssystem.

    I denna rapport analyseras och utvärderas om det är möjligt att använda sig av elektrokemiska kondensatorer som energilagringssystem för fordonet, både i dagens läge samt år 2017. Det är året då konceptfordonet ska presenteras. Problemområden såsom energidensitet, vikt och återladdning vägs in i analysen. Studien fokuserar enbart på energilagringssystemets dimensionering. Själva implementationen av systemet berörs inte.

    Resultatet från studien visar att det i dagens läge inte är möjligt att använda sig av ett energilagringssystem bestående av enbart elektrokemiska kondensatorer, det skulle bli för tungt. Det är dock fullt möjligt att använda sig av en kombination av elektrokemiska kondensatorer och batterier.

    Den nya europeiska körcykeln, som är en standard för blandad körning av ett fordon, har använts för att kunna se hur lång tid fordonet accelererar under en tidsperiod på 20 minuter. Utifrån detta har vi kommit fram till att ungefär 400 Wh energilagring med elektrokemiska kondensatorer är lagom. Därmed är ett energilagringssystem på 50 kg lite för lätt, kapaciteten skulle då bli för liten. Ett system med 100 eller 150 kg skulle passa bättre, beroende på hur stor kapacitet Precer vill att fordonet ska ha och hur lätt det behöver vara. Det är också en ekonomisk fråga, men det avhandlas inte i denna rapport.

    År 2017, när konceptfordonet ska presenteras, skulle en mycket större del av energilagringssystemet kunna bestå av elektrokemiska kondensatorer. Detta tack vare att en stor teknisk utveckling förväntas ske både på kondensatorsidan samt på batterisidan.

  • 15.
    Ernebro, Samuel
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Bernhardsson, Lars
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Xboxen som dator2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Degree Project was performed at Easygamer in Skoghall which is a company that among other things modifies most of today’s gaming consoles and sells computer products. They wanted us to transform an Xbox to a “student computer”. You will be able to get a quite powerful computer for not that much money. With this kind of computer you will be able to use “office applications”, listen to music, use the internet etc. But of course, also use the Xbox as a gaming console, if you want to.

  • 16.
    Grill, Andreas
    et al.
    Karlstad University, Faculty of Technology and Science.
    Englund, Robin
    Karlstad University, Faculty of Technology and Science.
    Analysis of Fix‐point Aspects for Wireless Infrastructure Systems2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A large amount of today’s telecommunication consists of mobile and short distance wireless applications, where the effect of the channel is unknown and changing over time, and thus needs to be described statistically. Therefore the received signal can not be accurately predicted and has to be estimated. Since telecom systems are implemented in real-time, the hardware in the receiver for estimating the sent signal can for example be based on a DSP where the statistic calculations are performed. A fixed-point DSP with a limited number of bits and a fixed binary point causes larger quantization errors compared to floating point operations with higher accuracy.

    The focus on this thesis has been to build a library of functions for handling fixed-point data. A class that can handle the most common arithmetic operations and a least squares solver for fixed-point have been implemented in MATLAB code.

    The MATLAB Fixed-Point Toolbox could have been used to solve this task, but in order to have full control of the algorithms and the fixed-point handling an independent library was created.

    The conclusion of the simulation made in this thesis is that the least squares result are depending more on the number of integer bits then the number of fractional bits.

  • 17.
    Gustafsson, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Studie av reaktivt effekt2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Den här rapporten är en analys av reaktiv effektförbrukning från två anläggningar i Karlstad, Heden och en nätstation som kallas T375. Med rapporten vill jag skapa en bättre förståelse för hur den reaktiva effektförbrukningen ser ut i elnätet och hur den påverkar kunden. Varje negativ reaktiv effekt ska kontrolleras och med hjälp av värdena ska den mest lämpade åtgärden tas fram. Karlstads Elnät AB, som har ansvar för företaget Heden och nätstation T375, samlar in sina värden från anläggningar en gång om dagen och värdena kontrolleras under natten. Värdena från nätstation T375 som använts under den här rapporten är från år 2000. Hedens värden är från år 2014. Värdena har analyserats med hjälp av kalkylprogrammet Microsoft Excel.Värdena har analyserats utifrån energiförbrukning och effektfaktor samt max-, min- och medelvärden. Det har skapats grafer över den reaktiva och den aktiva energiförbrukningen samt effektfaktorn under en viss tidsperiod. Resultatet kommer från analysering av effektförbrukningen och effektfaktorn från båda anläggningarna samt teoretiska åtgärder för att motverka den kapacitiva reaktiva effektförbrukningen har tagits fram.

  • 18.
    Gustafsson, Martin
    et al.
    Karlstad University, Division for Information Technology.
    Eriksson, Erik
    Karlstad University, Division for Information Technology.
    Kapacitivt tändsystem2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An ignition system is needed to control an engine. This ignition system has to be able to provide the right energy at the right time. Due to the lack of efficiency in older mechanical and early electronic systems, we planned to design and construct a capacitive discharge ignition system. This system includes a microcontroller that will calculate the spark timing. The system controls the spark timing depending on the engine speed. The engine speed is measured using a sensor mounted near the engine flywheel. The basic idea is to split the system into three subsystems, the charge subsystem, the ignition subsystem and the controller. The first step was to design, simulate and construct each subsystem. The next step was to merge these subsystems into a working unit. The result was a fully functional capacitive ignition system.

  • 19.
    Hamanee, Sahaphol
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Simuleringsbaserad analys av toppeffektreducering med batterisystem i lokalnät2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a simulation model developed in MATLAB® in consideration of system losses based on lithium ion-battery is presented. The purpose of the simulation model is to investigate peak shaving potential in the residential distribution network. In other word to determine an optimal threshold limit and battery capacity depending on if the battery system is placed at the transformer or household level. In the report there were economic calculations executed showing that profitability of investing in a battery system depends on the threshold limit and battery capacity.

  • 20.
    Hideblad, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Equipment for Accelerated Vibration Testing2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increasing complexity with the decrease in size of EEE – components (Electronic, electric and electromagnetic) raises the question on how higher energy frequencies will affect the components and their continuous development. The most common vibration testing equipment currently in use within the automotive industry and SCANIA CV AB are the electrodynamic shaker (ED system). This thesis covers the characteristics of different vibration testing equipment while analysing their strengths and weaknesses, not only for the automotive industry but also including equipment more commonly handled within the aero and space industry. The project aims to find a complement for the ED system and study the possibility for its replacement in the automotive industry.In particular, experiments are carried out and documented on a so-called “Repeatable shaker system” (RS system) for the purpose to get a better understanding on the functions of the equipment and its overall differences compared to the electrodynamic system when it comes to random vibration testing.It became clear that complementing or replacing the ED system is difficult and that the RS system work fundamentally different in comparison. Accordingly, the RS system is not a potential replacement for our purpose and it cannot perform at the same level of precision but instead is able to achieve higher energy frequencies overall, making it still ideal for its intended purposes, but not as a replacement of the ED system.

  • 21.
    Hirsch, Tobias
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    3D-modellering av elanläggningar: Kort- och långsiktiga fördelar med 3D-modellering av elanläggningar2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The work has been done at Sweco Industry in Karlstad with the intent to investigate the possibility to construct electrical sites in a 3D-model instead of the usual 2D. Since 3D-models are already in use by the mechanics department the electrical department wanted an evaluation of the advantages and disadvantages this might bring. In the future it’s pretty much already decided that 3D is the way to go, but in what extent and which parts of an electrical site that is especially suited for this was not clear.

    To collect facts and opinions about this I have completed several interviews with experienced constructors at Sweco and the program developers AVEVA. The material from these interviews was then analyzed and summarized in this report. I was also given the opportunity to learn the program myself to easier understand how a constructor works and which possible problems that might appear in the daily work.

    The main goal with this project was to summarize and analyze the possible advantages and disadvantages that 3D-construciton might include. The hardest part of this work was that, by the start of the work process, no project had been done with this method. This meant that no statistics or information was available and most of the fact had to come from peoples own experiences. At the end of the work process, two projects had been started with the 3D-method. These can in the future be used to evaluate the method. 

  • 22.
    Jansson, Peter
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Dämpning av pulsationer i kylkretsen2014Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    The heat pump emits noise when the temperature increases, which can be a disturbing factor to the surrounding environment. The heat pump could become more attractive to the costumers if the noise was decreased.The objective with the examination paper is to investigate if the noise and vibrations could be measured that occurs when a compressed gas expands and leaves the compressor rapidly. A cheap, costeffective and simple damper will be constructed.The dampers that were tested had a diversity of shapes and forms, and at last the damper with damping materials gave a decreased vibration.

  • 23.
    Jönsson, Kristin
    Karlstad University, Faculty of Technology and Science.
    RF-modul2006Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The idea behind this project was to construct a general RF-module as small as possible and the RF-module should be able to connect to an existing design. A transceiver from Chipcon, CC1100, was used together with a microprocessor MSP430 from Texas Instruments. To make

    the RF-module handle a wide input voltage range a voltage regulator, XC6202, from Torex was used. The circuit board is a four layer card with one layer ground and components on one side. The components are placed to full fill there purpose and at the same time make the card

    as small as possible. With help from a network analyzer the network to the antenna was examined so it obtained a value near 50 W. The RF-module was programmed and tested with good result, but I didn’t participated.

  • 24.
    Kahn, Daniel
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Saar, Nimrod
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Analys och utredning av hjulmotorer/kontrollsystem samt SotA inom det valda området ur ett elektromekaniskt perspektiv2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Precer Group is a Swedish company that develops and provides technological solutions to produce electricity by burning solid fuels. Precer has developed a unique system based on an adaptive technique for charging different kinds of hybrid vehicles such as cars, trucks, utility vehicles and boats but, also for housing in the form of electricity generation. They have a patent on a heat engine that drives a generator that charges the battery.Precer Group also has collaboration with the European Space Agency (ESA) in which they are working together to develop new types of powertrains and fuels to create very environmentally friendly hybrid vehicles that do not run on fossil fuels.We have been working together with Precer Group to try to determine how todays technology with wheel motors and the motor controls can be implemented in this specific concept vehicle and also see how the problem that exsist with this tecnology e.g. unsprung weight, power and controlfunctions and systems can be solved. We have concentrated on finding out the best performance for in-wheel motors and the best functionality, safety and usage of motor controllers available on the present market.We received a list of specifications from Precer that we adhered to when we checked and analyzed different manufacturer’s motors. The reason behind attempting to use wheel motors, in oppose to more conventional motors, is weight reduction. By using wheel motors we are able to omit axels and gearboxes, thereby reducing the total weight of the vehicle which must be kept within a maximum limit. Another reason is that the use of in-wheel motors gives possibilities to implement smart electrical systems to control the motors and the vehicle through CAN buses. This leads to faster and more complex steering of the vehicle to improve the efficiency, stability and safety. Precer also specified the use of four separate wheel motors in order to utilize a four-wheel drive concept. We have compared the performance of the various motors and controllers available, and we have concluded which motor best suits this vehicle. Through physical calculations and functional comparisons of data that we have received from some of the leading companies we have come to results that show that systems which integrate the in-wheel motors and the controllers demonstrate a better performance when it comes to acceleration and climb ability. Also their functionality is considerably higher than the systems that integrate in-wheel motors with a universal controller. Although it’s able to configure the universal controllers considerably more and so make it possible for the user to personalize the system by desire.

  • 25.
    Kane, Bridget
    et al.
    St James’s Hospital, Dublin.
    Luz, Saturnino
    Trinity College Dublin.
    A study of the impact of collaborative tools on the effectiveness of clinical pathology conferences2004In: Computer Human Interaction: 6th Asia Pacific Conference, APCHI 2004, Rotorua, New Zealand, June 29-July 2, 2004. Proceedings / [ed] Masood Masoodian, Steve Jones, Bill Rogers, Springer, 2004, p. 656-660Conference paper (Refereed)
    Abstract [en]

    Multidisciplinary conferences in hospitals are becoming an everyday part of health service delivery and being recommended as a mechanism for ensuring quality patient care and management. This paper reports preliminary findings of an ethnographic study of Clinical Pathology Conferences with Respiratory teams. Educational, patient management and organizational objectives of the conference are identified. The findings so far suggest that collaborative technologies have the potential to improve the effectiveness of clinical conference activity. Time, location and missing artefacts are identified as being issues as well as the coordination of the series of events associated with patient investigative and assessment procedures. The implications of recording data and interactions at the conference are also being investigated.

  • 26.
    Kihlström, Andreas
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics. Karlstad University, Faculty of Technology and Science.
    Weivert, Joakim
    Karlstad University, Faculty of Technology and Science. Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    RR PLC Application Code: a Benchmark Study2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This degree thesis is performed at Rolls-Royce at the Control Systems division.

    The assignment is to compare two different PLC development tools and determine how a transition toa new PLC development tool would be. The programs that will be compared is the current toolAutoCAD with the extension ACG and CoDeSys.

    A transition from AutoCAD to CoDeSys is realizable but will take considerable time and effort. Theeasiest way to achieve this is to during the transition generate an export file from the existing drawingsin AutoCAD which then can be imported to CoDeSys. By this CoDeSys can be used as a platform fordeveloping. This is fully realizable because ACG which generates the C code can be modified togenerate almost any export file.

  • 27.
    Klarin, Christoffer
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Utredning och implementation av OPC-kommunikation med .NET2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate the OPC standard OPC Data Access and the corresponding part in OPC Unified Architecture, and to implement OPC communication in a system.

    The need for a communication standard was born out of the interoperability problems that existed mainly in industrial production systems. With an OPC interface implemented between a data source and an application, the data exchange can be done in a standardized way.

    OPC Foundation, which is an organization that provides various OPC standards, has now developed two OPC standards, Classic OPC and OPC Unified Architecture. Classic OPC is a set of specifications that are based on COM and DCOM interfaces, which means that these specifications are tied to the Windows platform. OPC Unified Architecture provides a safer and more versatile communications interfaces than the Classic OPC standard provides, thanks to the communication stack.

    The practical bit of the project consisted of implementing OPC communication in a system. Two parts that were included in the implementation was to create a test environment and to develop an application on top of the class library that dealt with communication with OPC DA and OPC UA servers.

    The OPC Unified Architecture standard defines only the format of the message before it reaches the communication stack. This makes it possible to provide communication stacks that communicate according to other protocols and formats in the future, which allowing OPC Unified Architecture to be adaptable to future needs and thus will be an option for an interoperable system for a long time to come.

  • 28. Kostic, Joca
    et al.
    Bulory, Armita
    Analys av orsaker och tid för åtgärder vid driftstörning i elnätet2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 29. Larsson, Jerker
    et al.
    Granath, Joakim
    Kompensering av spänningsfall i elnätet inom processindustrin med effektkondensatorer2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    We do our thesis work on AF in the Karlstad at Nordic Paper in Säffle. Nordic Paper works with greaseproof paper and includes two large paper machines at its facility.

    Nordic Paper has built a new section of its facility consisting of six new motors. These engines have a voltage drop at the motor starter and our goal is to reduce this voltage drop as much as possible. This is to be reduced by means of capacitors. This voltage drop can in turn lead to that they charge too much reactive power on the network because the engines require very reactive power. This reactive power outtake in turn can lead to penalties from the network owner. The voltage drop can cause complications to the equipment.

    We have concluded that there are two good compensation methods to compensate the reactive power of these is by using power capacitors that are running all the time and starting battery which is running until the engine has started in the normal operating range.

    A calculation was made to the capacitors and placements to the capacitors were produced by hand. We should do the same calculations in Neplan but a license to the program was missing so we couldn’t do any calculations.

    The connection of the output capacitors reduced the voltage drop is not as much as was desirable when the simulation was done in Neplan

    Calculations for alternate starting methods were developed when the result was not what we had hoped for.

  • 30.
    Lindkvist, Linus
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Hagberg, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Transienta strömmar i HVDC-Light2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 31.
    Lindström, Björn
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Metodik för analys av batteriets laddningscykel i entreprenadmaskiner: Prototypbyggnad och teori2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Volvo Construction Equipment AB, Volvo CE, is a global producer of construction machines. This thesis has focus on the battery in these machines that are providing power to the electrical system and start engine during cranking.

    With today’s technology there are new demands on the power supply in construction machines. The largest difference is in the demand for power when the engine is off and the only power source is the battery. A Lead-Acid starter battery is not constructed for this type of demand. Because of this Volvo CE has begun to build knowledge about how the charge in the battery is used and cycled during usage.

    This thesis has processed questions about which parameters and trends that are relevant to evaluate regarding the level of charge in the battery. The theory behind these parameters has been examined, described and evolved in the suggested methodology for analysis of the level of charge in the battery in construction machines.

    A method on how to extract identified data from the construction machines has been described in the work on the prototype equipment for collecting the data.

    The suggested methodology in this thesis to analyse the level of charge in the battery in construction equipment based on the user case may help to give answer to the question if the batteries used today are suitable for the new generation of construction machinery.

    This thesis contains a news value for Volvo CE and others since this methodology has not been described or used before at Volvo CE. The thesis also provide suggestion for a road to build more knowledge on batteries within Volvo CE.

  • 32.
    Lynghed, Christoffer
    et al.
    Karlstad University, Faculty of Technology and Science. Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Andersson, Viktor
    Karlstad University, Faculty of Technology and Science. Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Beräkning av massa genom mätning av hydraultryck2009Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Our task was to develop an algorithm for the relationship between mass and hydraulic pressure in a hydraulic system in a forklift. The algorithm was then to be implemented in a prototype of a forklift scale. The solution had to be cost-effective.

    To examine the relationship we performed series of measurements in which various components were tested. The results of the measurements were analyzed and we found a correlation between mass and hydraulic pressure. Due to this we could write a code for a forklift scale prototype with features.

    The forklift scale prototype worked on the forklift that we used but it needs to be tested and evaluated further in more forklifts before a final product can be made.

  • 33. Lötbrink, David
    et al.
    Sjöberg, Erik
    Ägande/ övertagande av IKN-nät: fördelar, nackdelar, för industri och nätbolag2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 34.
    Maninnerby, Henrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Simulering av ett elnät med hänsyn till förnybar energi: En studie av möjliga lösningar på problemet med fler elbilar i elnätet2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to simulate different scenarios where all vehicles are replaced by electric vehicles in the future.

     

    An addition of electric vehicles to the electric grid is not easy to handle, especially not if the consumers choose to charge their vehicles with higher power. As can be seen in the results of this report, flexible demand through power management is a good option to reduce overall power consumption. Of course, customers will have to agree to that their consumption is controlled in this manner.

     

    Using solar cells during the summer works well, but it’s harder wintertime as the largest electric demands arise during the night, when there is close to no sunlight. However, in the case of batteries, they may be helpful. Possibly by letting the solar cells charge the battery during the day and then use it to help charge the electric vehicle during the night. Unfortunately, it was not possible to include this scenario as the used software was unable to handle batteries in that way.

     

    By completely replacing the heat source, in this case with district heating, and thus releasing available power in the transformer, turned out to be the best option. In this way, virtually all predicted amounts of electric cars could be charged with optional charging strength between 3.7 and 11 kW.

     

    As for the T422 transformer, there is no choice but to replace it if a larger number of electric vehicles wants to start charging there. At present, it can handle a maximum of 10-20 electric vehicles that charge at the lowest power as there is only about 50 kW available there winter time.

    District heating cannot be applied either as the connected customers do not use electric heating.

  • 35.
    narra, suresh
    Karlstad University, Division for Information Technology.
    Pulse Response Based Identification of Low-order Models2006Independent thesis Advanced level (degree of Magister), 10 points / 15 hpStudent thesis
    Abstract [en]

    In practice, many systems are modeled by first and second order models including a time delay. These low-order models can often be used to describe the most important and characteristic features of a system and be a base for control design. In industry, it is important to have fast, reliable, and easily applicable methods for estimating the parameters in such models. It is well-known that, for practical reasons, many systems can not be excited by an arbitrary input signal. However, a pulse-shaped input signal can most often be used. The aim with this thesis project is to study identification of low-order models based on pulse-shaped input signals.

  • 36.
    Nilsson, Andreas
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Beermann, Eric
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Utvärdering av tillgänglighet samt utveckling av summalarm för övervakningssystem2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Detta examensarbete har utförts på uppdrag av Stora Enso Skoghall AB.

    För ett vinstdrivande industriföretag som Stora Enso är oplanerade stopp, oberoende av orsak, kostsamma och skall i största möjliga utsträckning undvikas. Att effektivt kunna förutse och förhindra haveri har därför hög prioritet.

    Mätsystemet Argus CC gör, bland annat, analyser av varvtalsavvikelser med hjälp av pulsgivare. Dessa mätningar ligger sedan till grund för inplanering av underhållsstopp.

    Syftet med detta examensarbete är att utvärdera hur utnyttjandet av Argus CC sparar in på kostsamma och onödiga underhållsstopp, samt att konstruera en kommunikationslänk mellan Argus CC och ABB’s styrsystem.

  • 37.
    Nilsson, Henrik
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Magnusson, Fredrik
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Övervakning för DC-system2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis was performed for AIAB DC Systems in Karlstad.

    Our task is to make a monitoring system for DC-system. The unit is used to supervise voltage and isolation in isolated DC-systems. The unit shall alarm if there is any failure in the system. The company now has an analog solution on this product but now they want a digital version.

    An 8-bit RISC processor has been used to take care of the logic. The programming has been done in assembler with the help of a developing kit. The program operates with two buttons and a display.

    The program that we made needs to be added with some functions. We haven’t got a prototype ready yet due to the project time was expired.

  • 38.
    Nilsson, Johan
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    AC Ion Current Interface2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    An effective way to extract combustion parameters from a spark ignited engine is to measure the level of ionization. One way to do this is to use the spark plug as a sensor.

    Until now this has been achieved by applying a DC voltage over the spark gap which causes an electrical field. The electrical field together with the ionization process gives cause to an ion current which can be measured and analyzed. Previous research suggests that it would be beneficial to replace the DC voltage with an AC voltage.

    The focus in this thesis is on the hardware and how to best implement an AC voltage to the existing ion sensing system. Both simulation- and hardware models will be constructed. These models will be tested and analyzed to evaluate both benefits and drawbacks of an AC ion current sensing system.

  • 39.
    Norenfalk, Eleonor
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Optimering av driftläggningar i Fortums nät2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 40.
    Nouraei, Yaghoob
    Karlstad University, Faculty of Technology and Science.
    Värmepumpars inverkan på elkvaliten2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Modern technology and fast development of heat pumps, the hunt for savings in energy consumption and the strive for environmentally friendly energy sources, convenience, and financial profit, have made heat pumps a reasonable alternative for the heating of houses.

    When the heat pump starts it will consume a considerable amount of current, which may result in a short-lived voltage-drop if the power grid is weak compared to the start-up current.

    The company Fortum Distribution which owns and administrates electrical network is interested in an investigation that deals with heat pumps affect on the quality of electricity.

    The purpose of this investigation is to study fast electrical fluctuations (flicker) as a result of start-up currents for single as well as multiple heat pumps on the same electrical station and from this evaluate whether there will be any problems installing heat pumps.

  • 41.
    Olsson, Joakim
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Effekter av tidiga reflektioner vid musikreproduktion2014Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
  • 42.
    Palmlund Wahlgren, Henrik
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Demonstratortest av gassensor baserad på tryckt organisk elektronik och jonledande papper2013Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Researchers at Karlstad University have developed a method for making paper ion conducting. The reasearchers want to test this technique in various applications and produce products that make use of the ion-conducting paper. Hopefully this will drive the development forward and result in new applications for the ion-conducting paper.

    This study was to test the possibility of manufacturing a gas sensor of conducting paper along with electrodes of conductive polymers printed on the paper. By comparing the paper sensor with an electrochemical cell in which the electrodes of conductive polymer replaces electrodes of metal and ion-conductive paper replaces the liquid electrolyte in the electrochemical cell, it was hoped that it would be possible to measure the oxidation and reduction reactions that a gas could introduce at the electrodes.

    It was shown that it is possible to measure a potential difference in the range of 0.3 V to 0.5 V between the electrodes when exposing an electrode to 100% oxygen. The reaction that takes place is relatively slow and the reaction rate is partly due to the distance between the electrodes.

    Since the sensor can measure oxidation and reduction reactions it is possible that, in further development of a sensor, the sensor can be made ​​into a versatile sensor with more applications than gas measurement as there are many more ways to oxidize or reduce the electrodes than by exposure to oxygen.

    During the study there have been discussions and meetings held with various companies in the sensor industry to be able to specify what the market demands of a sensor made ​​of paper and the requirements that must be placed on the sensor for it to be interesting for the companies.

  • 43.
    Paluri, Suraj
    et al.
    Karlstad University, Faculty of Technology and Science.
    Patluri, Sandeep
    Karlstad University, Faculty of Technology and Science.
    A Study of Impulse Response System Identification2007Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In system identification, different methods are often classified as parametric or non-parametric methods. For parametric methods, a parametric model of a system is considered and the model parameters are estimated. For non-parametric methods, no parametric model is used and the result of the identification is given as a curve or a function.

    One of the non-parametric methods is the impulse response analysis. This approach is dynamic simulation. This thesis introduces a new paradigm for dynamic simulation, called impulse-based simulation. This approach is based on choosing a Dirac function as input, and as a result, the output will be equal to the impulse response. However, a Dirac function cannot be realized in practice, and an approximation has to be used. As a consequence, the output will deviate from the impulse response. Once the impulse response is estimated, a parametric model can be fitted to the estimation.

    This thesis aims to determine the parameters in a parametric model from an estimated impulse response. The process of investigating the models is a critical aspect of the project. Correlation analysis is used to obtain the weighting function from the estimates of covariance functions.

    Later, a relation formed between the parameters and the estimates (obtained by correlation analysis) in the form of a linear system of equations. Furthermore, simulations are carried out using Monte Carlo for investigating the properties of the two step approach, which involves in correlation analysis to find h-parameters and least squares and total least squares methods to solve for the parameters of the model. In order to evaluate the complete capability of the approach to the noise variation a study of signal to noise ratio and mean, mean square error and variances of the estimated parameters is carried out.

    The results of the Monte Carlo study indicate that two-step approach can give rather accurate parameter estimates. In addition, the least squares and total least squares methods give similar results.

  • 44.
    Persson, Daniel
    et al.
    Karlstad University, Faculty of Technology and Science.
    Johansson, Christoffer
    Karlstad University, Faculty of Technology and Science.
    Gränssnittsanpassning av robotiserad mätdatainsamling2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The project is about integrating a recently bought robot system into an already existing measurement data collection system. This robot is meant to replace an older and different robot model. The project was performed at Novanik AB in Karlstad. This report will show how the robot has been voltage adjusted to fit the Swedish electric power system because the robot was bought from USA and used in their electric power system. The report will also show how the robot successfully was adjusted to be controlled by the existing software (which was used for the old robot).

  • 45.
    Persson, Klas
    Karlstad University, Division for Information Technology.
    Utredning av förutsättningar för att direktjorda processnätet på ett pappersbruk2006Independent thesis Basic level (professional degree), 10 points / 15 hpStudent thesis
    Abstract [en]

    To increase the protection against electrical fields in the distribution net on Stora Enso’s mill in Skoghall it will be investigated if it’s possible to use direct earth instead of only protective earth as of today. Because the net only has protective earth the company wants to know if the dimensions of the cables are enough to meet the lesser shortcut voltage in a net with direct earth. The smallest shortcut current when using direct earth occurs between one phase and the zero and will be aproximately times less than when using non direct earth where there is not a zero and the shortcut can onlyu occur between two phases. This means that when building a non direct eart net you can use longer or thinner cables with more resistance than you could using direct earth. New cables are not an alternative when the cost would be to great and the downtime of the machines would be too long. This inquiry will show the maximum cabel length from the different protections to the different engines can be if you want to use direct earth and be sure that the fuses will burn when an error occurs.

  • 46.
    Popaja, Armin
    et al.
    Karlstad University, Faculty of Technology and Science.
    Sundberg, Fredrik
    Karlstad University, Faculty of Technology and Science.
    Konstruktion och programmering av lerduvekastare2008Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This degree thesis is based on an assignment from BEOMAT in Storfors. BEOMAT is a company that constructs and sells

    clay pigeons to both the national and international market.

    Our main purpose with this paper is to find a solution/system that can replace the expensive and space demanding

    Olympic trap facility. Our solution will replace fifteen clay pigeon throwers with one automatic thrower who

    simulate all throwers together. The system will be provided with an appropriate control system for mass production

    therefore this system needs to be user-friendly so no previous knowledge is required.

    Totally 405 different throw coordinates will be stored in the programme in nine different subprograms. According to

    the Olympic-rules the throwers should coincidence within certain specified conditions, this will be solved with an

    randomizer in the programme. The equipment needs to be able resist all outdoor weathers since it is going to be

    installed outside. The software has to be enabling to update so the thrower can be reprogrammed or updated for any

    specific requirements, regulatory reforms etc.

    In addition, the reader gets an insight into general aims and problems we encountered and resolved during along the

    way. Thereafter various forms of clay pigeon shooting are presented to give the reader a general picture of how the

    sport is executed. Finally we describe our actions, the selection of the equipment and also a little about the

    programming of both PLC and display.

    The PC control system that was assembled on the clay pigeon shooter earlier did not was a good solution with our

    requirements. The old system was replaced with PLC model EC-4P-221-MRAD1 with an external steering display.

  • 47.
    Ressem, Björn
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    HRTF lösning för stereodipol2014Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
  • 48.
    Samuelsson, Robert
    Karlstad University, Faculty of Technology and Science.
    Karlstad Vision 100 000 och dess implementering för Karlstads Elnät AB 2011-20152011Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The town of Karlstad has a long term project called Vision 100 000 which aim is to increase the population towards 100 000 inhabitants. This will of course put a strain for the town’s energy distribution grid. This is a work about trying to predict the grids power usage would be for the next five years if the city building plan is finalized. Those predictions are mainly going to be done through calculations with a database program called Facilplus and by checking the measured history of power usage per hour on certain selected customers by the program CustCom.  The peak for power usage happened the 22 December at 4 am. This date is important because it would give the main measure for how much it the grid is able to deliver. The future prognoses of the power usage are then going to be calculated. This is going to be done by making sure that the total areas of newly constructed buildings are going to be measured. A mean value for area and power usage is then going to be calculated for respective single houses and apartment houses. This would in turn give the important necessary value that would enable to give Karlstad Elnät AB a mean to calculate a new primarily prognosis for the next five years plan. These prognoses would then be used as plans how to newly constructed habitation areas would affect the energy grid in Karlstad.

  • 49.
    Segerström, Mikael
    et al.
    Karlstad University, Division for Information Technology.
    Kristiansson, Jörgen
    Karlstad University, Division for Information Technology.
    Dokumentation av elsystem vid Kvaerner Kamfab AB, Karlstad2006Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The assignment has been to label and document Kvaerner Kamfab’s electrical system. This is the first phase of reconstructing the switchgear in order to increase the efficiency.

  • 50.
    Silvén, Daniel
    et al.
    Karlstad University, Faculty of Technology and Science.
    Karlssson, Patrik
    Karlstad University, Faculty of Technology and Science.
    Sensorfinger2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The goal with this degree project was to find a solution with different components to the existing design, or find a sensor with similar function that could replace the previous design of the sensor finger.

    Our work has been limited by ESAB due to the user friendly mechanical design of the previous sensor finger. After examining different sensors we choose to use strain gages as sensors for the mechanical sensor finger. With this choice we also needed to suggest a theoretical design for a mechanical attachment of the sensor finger.

    We have designed two separate Wheatstone bridges with separate instrumental amplifiers (INA125). The output signals from the bridges are relatively small and need to be amplified around 2000 times.

    The zero balancing of the bridges has been done manually with potentiometers but we have also suggested a solution where the zero balancing can be performed by a push-button. The button is placed where you cannot push it unintentionally.

    The result of this degree project is a circuit on a veroboard, a designing proposal for the attachment and the sensor finger.

    In order to further develop this design it would be necessary to build a prototype to evaluate its life span and find the optimal sensitivity.

12 1 - 50 of 60
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