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  • 1.
    Abboud, Mohamad Moulham
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Simulation of 3ph induction motor in Matlab with Direct and Soft starting methods.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Asynchronous machines are considered nowadays the most commonly used electrical machines, which are mainly used as electrical induction motors. Starting the induction motor is the most important and dangerous step. The theory behind this project is based on representing the real motor by a set of equations and values in Matlab using the subsystem feature, forming a corresponding idealistic motor in a way where all the physical effects are similar. The motor is started under different loads in two methods: Direct and Soft starting. Each method is studied and discussed using supporting simulation of currents, torque, speed, efficiency and power factor curves.

  • 2.
    Ahmad, Muhammad
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Jhanzeb, Jhanzeb
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Modeling and Simulation of an Electrostatic Precipitator Including a Comsol Multiphysics Guide for Modeling an ESP2011Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Gaseous exhaust of different industries contains dust particles of different chemical precipitates that are harmful for the environment. Electrostatic Precipitators are very often used in industries to filter their gaseous exhaust and to prevent the atmosphere to being polluted. Electrostatic Precipitators are very efficient in their work. Electrostatic Precipitators use the force of the electric field to separate the dust particles from gaseous exhaust. Electrostatic Precipitators charge the dust particles and remove these particles by attracting these charged dust particles toward the collecting plates. The charging of dust particles requires a charging zone. When gas passes through that charging zone, the dust particles in the gas stream become charged and then these charged particles are attracted toward the collecting plates. The design of an Electrostatic Precipitators requires the knowledge of its working principle and the problems that often arise during its working. This thesis is the study of the working and the problems of the Electrostatic Precipitators. The main reason for problems in working of an Electrostatic Precipitator is the dust resistivity. This dust resistivity affects the collection performance of an Electrostatic Precipitator. This thesis also contains the simulation of an Electrostatic Precipitator. In the simulation part, the Electric Potential and the Electric Field of an ESP is modeled in an ideal condition, when no gas is flowing through the ESP. The industrial software Comsol Multiphysics is used for the simulation. A Comsol Multiphysics guide is given in appendix of this thesis report that provides information about using this software.

     

  • 3.
    Akhtar, Asim
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Alahi, Hassan Mateen
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Sehnan, Moeed
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Simulation of Phased Arrays with Rectangular Microstrip Patches on Photonic Crystal Substrates2012Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the investigation of photonic crystals as a substrate in microstrip phased array antennas. Alumina with a relative dielectric constant of 9.6 is used as substrate to obtain miniaturization of the components in the high-frequency range. The proposed design consists of four rectangular patches in a linear array conguration operating at 12 GHz. The antenna elements are excited by a microstrip feed line using the inset feeding technique for perfect impedance matching. A beam steering of 20o is achieved using a switched line phase shifter. Antenna parameters, including impedance matching, bandwidth, gain, directivity and the S parameters of the proposed array antenna are obtained. The simulation results are obtained with the Advanced Design System (ADS) simulator.

  • 4.
    Akkasli, Cem
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Methods for Path loss Prediction2009Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    Large scale path loss modeling plays a fundamental role in designing both fixed and mobile radio systems. Predicting the radio coverage area of a system is not done in a standard manner. Wireless systems are expensive systems. Therefore, before setting up a system one has to choose a proper method depending on the channel environment, frequency band and the desired radio coverage range. Path loss prediction plays a crucial role in link budget analysis and in the cell coverage prediction of mobile radio systems. Especially in urban areas, increasing numbers of subscribers brings forth the need for more base stations and channels. To obtain high efficiency from the frequency reuse concept in modern cellular systems one has to eliminate the interference at the cell boundaries. Determining the cell size properly is done by using an accurate path loss prediction method. Starting from the radio propagation phenomena and basic path loss models this thesis aims at describing various accurate path loss prediction methods used both in rural and urban environments. The Walfisch-Bertoni and Hata models, which are both used for UHF propagation in urban areas, were chosen for a detailed comparison. The comparison shows that the Walfisch-Bertoni model, which involves more parameters, agrees with the Hata model for the overall path loss.

  • 5.
    Aldrin, Martin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Implementering av ett inbyggt system för automatisk styrning av en robotbil.2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes a project for the bachelor degree in electrical engineering at Växjö University. The purpose with this project is to construct a guidance system for a robot car, a program that prevents the car from colliding with objects when moving without external control. The robot could also be controlled from the computer through a virtual instrument implemented in Labview. The necessary hardware for steering and communicating has been constructed. The software is implemented using three different programming languages, C, Perl and Labview.

  • 6.
    Al-Najjar, Hamid
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Gustafsson, David
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Uppträdande problem i elkraftsammanhang: Orsak, verkan och åtgjärder2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 7.
    Andersson, Magnus
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Elektronikingenjörens vardag: - ett rymdäventyr2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Masteruppsatsen Elektronikingenjörens vardag - ett rymdäventyr är skriven inom programmet yrkeskunnande och professionsutveckling vid Linnéuniversitetet. Uppsatsen beskriver ett yrkeskunnande som både innehåller avancerade datorsimuleringar och handfasta lödningar av elektriska komponenter, där teori och praktik samverkar. Uppsatsen är skriven i essäform, där händelser och situationer i yrkeslivet utforskas.

    Uppsatsen är skriven för att belysa yrkeskunnandet hos en elektronikingenjör från olika synvinklar; arbetslivet, lärandet och moralen. Genom att behandla tre olika sidor av yrket är tanken att få en större insikt om yrkets helhet. 

  • 8.
    Andersson, Sam
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Induktionsladdning av hybriddrivna fartyg: En framtida lösning för kustfartyg2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Projektet syftar till att bredda kunskapen om induktionsladdning och belysa de för- och nackdelar tekniken bär med sig på utrustning och kringliggande system.

    Med nya strikta krav på sänkta CO2 utsläpp väljer många redare att konvertera dieseldrivna färjor till hybrid eller helbatteridrift. För att tidseffektivisera hamnuppehållen krävs nya innovativa metoder för energiöverföring. Induktionsladdning av fartyg har provats på det norska fartyget MS Folgefonn med lyckat resultat.

    Utmaningarna med att upprätta en fungerande laddstation med sändenhet och mottagarenhet på ett fartyg, som på grund av väderförhållanden inte hålls helt stagnerad, har varit komplicerade.

    Belastningen på det lokala elnätet har också försvårat processen med en energiöverföring i den magnituden, på så mycket som 1 MW effekt.

  • 9.
    Arnell, Marcus
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Undersökning om möjligheten till småskalig vattenkraft i Björkefalls kvarn2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At present when the interest of environmentally friendly energy increases, small scaled water power is seen as an option to decrease Sweden's import of energy. In Sweden there are thousands of abandoned mills and small water power stations, these could with small means be restored and start to deliver energy again. In Björkefall, Olofströms municipality, there is a individually owned and abandoned mill. This rapport explores the possibilities for a small scale water power station there, for Olofströms Kraft AB.

    Small scaled, water power, power electronics, generator, turbine

  • 10.
    Augustsson, Joacim
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Larsson, Gustaf
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Styrning av stegmotor för robot med NICompactRIO2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report deals about controlling and regulating stepping motors and PM-motors by using thegraphical programming language NI Labview, with hardware NI CompactRIO and NI DAQ-USB.The implementation has been done by controlling a robot with a for the task built system, controllinga PM-motor by PWM and a own created controller.

  • 11.
    Azurdia Meza, Cesar Augusto
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Jon Mohamadi, Yaqub
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Implementation of the LMS Algorithm for Noise Cancellation on Speech Using the ARM LPC2378 Processor.2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    On this thesis project, the LMS algorithm has been applied for speech noise filteringand different behaviors were tested under different circumstances by using Matlabsimulations and the LPC2378 ARM Processor, which does the task of filtering in realtime. The thesis project is divided into two parts: the theoretical and practical part.

    In the theoretical part there is a brief description of the different aspects of signalprocessing systems, filter theory, and a general description of the Least-Mean-SquareAdaptive Filter Algorithm.

    In the practical part of the report a general description of the procedure will besummarized, the results of the tests that were conducted will be analyzed, a generaldiscussion of the problems that were encounter during the simulations will be mention,and suggestion for the problems will be given.

  • 12.
    Bart, Marco
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Spectroscopic methods for secure document authentication: An application to the automated handling of sheet-like objects2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For a long time, document security features, in particular inks and paper fibres, have been composed of materials with specific spectral characteristics. Consequently, spectral cues are playing an important role in forensic authentication methods. Document sorting machines, on the other hand, are characterized by a transport speed of often more than one meter per second. Furthermore, such systems are constrained with respect to size and cost. As a consequence, generic spectroscopic detection methods have rarely been used in that area. However, with recent technological advances in light-sources and in fast, low-cost spectrometers, generic spectroscopic analysis may become affordable for wider use in a not too distant future.

    The goal of this thesis project is evaluating the suitability of generic spectroscopic methods for the authentication of secure documents. To this end, the hardware and software for a spectroscopic sensor prototype was developed and integrated into an automated document sorting machine. This prototype consists of a grating spectrometer, covering the near UV and visible spectral range, combined with light guides and illumination sources for UV and IR wavelengths.

    Data sets for genuine and counterfeit value documents were captured using this prototype system and its authentication performance was tested based on host-side classification of this data. The algorithms employed for feature authentication rely on model-based vector correlation and the extraction of average intensity values from pre-defined wavelength ranges.

    The test results show that the authentication of value documents with such a system is feasible in principle, but also that there are limitations regarding component costs, the availability of light sources for farther UV wavelengths and the stability of spectral features on value documents in circulation.

    This work was performed in the context of Linnæus University’s Master Programme in Signal Processing and Wave Propagation. The sensor development took place at the research facility of Talaris Limited, Berne Branch in cooperation with the Laboratory for Optics and Photonics, University of Applied Sciences Berne, Switzerland.

  • 13.
    Biro, Thomas
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Nilsson, Börje
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Multiple scattering of microwaves from septum discontinuities in a circular bend2005In: Wave motion, ISSN 0165-2125, E-ISSN 1878-433X, Vol. 42, no 2, p. 109-125Article in journal (Refereed)
  • 14.
    Björn, Helander
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Optimization of Power System Efficiency2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project aims to optimize Ericsson's converter system by adjusting the bus voltage.For this purpose the converter system is modelled in Simulink with measurement datafrom the physical converters. To understand from where the losses originate I have asection with theoretical background for the losses in a buck converter. Anoptimization algorithm is developed to control the bus voltage in the simulations, andhopefully this algorithm will function as a template when it is implemented inhardware.

  • 15.
    Cijvat, Ellie
    et al.
    Lund University.
    Sjoland, Henrik
    Lund University.
    Two 130nm CMOS class-D RF power amplifiers suitable for polar transmitter architectures2008In: 9th International Conference on Solid-State and Integrated-Circuit Technology, ICSICT 2008., IEEE Press, 2008, p. 1380-1383Conference paper (Refereed)
    Abstract [en]

    Two class-D RF power amplifiers consisting of CMOS inverter chains have been designed and measured. The first amplifier operates at 1GHz and has a maximum output power of 12dBm, whereas the second operates at 1.5GHz and outputs a maximum of 6dBm. The amplifiers have been characterized for use in two different polar transmitter architectures, Pulse Width Modulation by Variable Gate Bias (PWMVGB) and Envelope Elimination and Restoration (EER). Using a standard 130nm digital CMOS process and off-chip passive components, maximum drain efficiencies of 32% and 39%, respectively, are achieved. The two amplifiers are compared with respect to output power and drain efficiency, including a qualitative analysis of losses. Moreover, their use in the two polar transmitter architectures is discussed.

  • 16.
    Cinar, Gökhan
    et al.
    Eskisehir Osmangazi University, Turkey.
    Aksimsek, Sinan
    Istanbul KÄultÄur University, Turkey.
    Nilsson, Börje
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Nordebo, Sven
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Cinar, Özge
    Eskisehir Osmangazi University, Turkey.
    Wiener-Hopf analysis of TM wave reflection by a step discontinuity on the junction of two coaxial waveguides with perfectly conducting and impedance walls2015In: Progress In Electromagnetics Research Symposium Abstracts, Prague, Czech Republic, July 6-9, 2015, Electromagnetics Academy , 2015, p. 1062-Conference paper (Other academic)
  • 17. Claesson, Lena
    et al.
    Håkansson, Lars
    Using an Online Remote Laboratory for Electrical Experiments in Upper Secondary Education2012In: International Journal of Online Engineering, ISSN 1868-1646, E-ISSN 1861-2121, Vol. 8, no Special Issue, p. 24-30Article in journal (Refereed)
    Abstract [en]

    The use of remote laboratories in courses at university level has been reported in literature numerous times since the mid 90?s. In this article focus is on activities carried out by teachers and students, at the Upper Secondary School Level, using the remote laboratory VISIR (Virtual Instrument Systems in Reality). The Upper Secondary School, Katedralskolan in Lund, Sweden, cooperate with Blekinge Institute of Technology, Sweden, in a project that concerns the introduction of remote laboratory environment suitable for Upper Secondary School science courses. A remote laboratory in electronics has been introduced and is used as a complement to the traditional workbench in the hands-on laboratory. Significant results from the project are; 1) the great interest shown by the students for the remote experiments, 2) the students appreciation for the fact that it was not simulations but actual real experiments, 3) the remote laboratory is easy to implement for use by both teachers and students and 4) it can be used simultaneously by many students.

  • 18. Cleasson, Lena
    et al.
    Khan, Imran
    Zackrisson, Johan
    Nilsson, Kristian
    Gustavsson, Ingvar
    Håkansson, Lars
    Chapter 7 – Using a VISIR laboratory to supplement teaching and learning processes in physics courses in a Swedish upper secondary school2013In: IT Innovative Practices in Secondary Schools: Remote Experiments / [ed] O. Dziabenko and J. Garcia-Zubia, Bilbao, Spain: Universidad de Deusto - Dpto. de Publicaciones, 2013Chapter in book (Refereed)
  • 19.
    Dahl, Hans
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Danielsson, Jonas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Elprojektering av kontorsbyggnad2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    WSP Systems i Växjö är ett konsultföretag som projekterar elanläggningar för allt från bostäder till industrier. Vår uppgift är att utifrån en kravspecifikation och arkitektritning ta fram ett ritningsunderlag för en mindre kontorsbyggnad på Ljungby lasarettsområde. Uppgiften går ut på att ta fram kanalisation-, kraft- och belysningsunderlag både med datorprogram och genom teoretiska beräkningar.

  • 20.
    Dahlskog, Robert
    et al.
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Arnell, Martin
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    En ljusbåges energi och konsekvenser: Att öka säkerheten och belysa konsekvenserna vid en ljusbåge på Mörrums Bruk2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med den här rapporten är att uppmärksamma elriskerna med ljusbågar som i många fall glömts bort, vilka risker man utsätter sig för när man oskyddad rör sig i närheten av transformatorer och ställverk. Rapporten ger också en överblick av vad som behöver förbättras på Södra Cell Mörrum för att öka elsäkerheten och undvika elskador. Ett mål är även att med hjälp av beräkningar kunna välja rätt skyddskläder och ha möjlighet att avgöra när en anläggning ska göras spänningslös vid elunderhållsarbete. Ett beräkningsblad har skapats i Excel för att enklare räkna ut energierna på olika transformatorer.

  • 21.
    Dalarsson, Mariana
    et al.
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Nordebo, Sven
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    The absorption of electromagnetic (EM) waves by a spherical dilute suspension of nanoparticles2017Report (Other academic)
  • 22.
    Dhasarathan, Iyyappan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Rathinasamy, Vimal
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Cui, Tang
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Wavelet Based SPIHT Compression for DICOM Images2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Generally, image viewers do not include the scalability for the image compressionand ecient encoding and decoding for easy transmission. They alsonever consider the specic requirements of the heterogeneous networks constitutedby the Global Packet Radio Service(GPRS), Universal Mobile TelecommunicationSystem(UMTS), Wireless Local Area Network(WLAN) and DigitalVideo Broadcasting(DVB-H). This work contains the medical application withviewer for the Digital Imaging and Communications in Medicine(DICOM) imagesas its core content. This application discusses the scalable wavelet-basedcompression, retrival and the decompression of the DICOM images. This proposedapplication is compatible with the mobile phones activated in the heterogeneousnetwoks. This paper also explains about the performance issues whenthis application is used in prototype heterogenous networks.

  • 23.
    Duzel, Adnan
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Programmerning av en industrikap med GRAPH 72008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essay is divided in several different parts, but all are tied up together by a fact that we want to increase productivity. We hope to do that by programming the PLC and to reach this with a better security for the person how are going to handle the cutting machine under it’s cutting process. We should as well look for some other ways to come up with better instructions and way to work and handle yourself during work. This programming is done in GRAPH7. This is a sequence block program from Siemens.

  • 24.
    Engström, Christian
    Lund University, Sweden.
    Bounds on the effective tensor and structural parameters for anisotropic two-phase composite material2005In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 38, p. 3695-3702Article in journal (Refereed)
    Abstract [en]

    This paper is concerned with the estimation of macroscopic properties such as the permittivity or the thermal conductivity of a composite material from the microstructure. A new method of estimating the microstructural parameters, such as the volume fraction of anisotropic two-phase composite material, is derived. The parameters are estimated using information from measurements of the random material or, in the periodic case, from numerical experiments. The method is used to derive new bounds on the effective tensor that incorporates information from measurements of a related parameter. These new bounds are called cross-property bounds. New tight bounds on low-order microstructural parameters are given in the anisotropic case.

  • 25.
    Ennals, Richard
    et al.
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Nelson, Björn
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Ingwald, Anders
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Johansson, Viktoria
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Lagercrantz, Victor
    Linnaeus University, The University Administration.
    Coping with social learning: Social and economic change through engagement2018In: Coping with the future: Rethinking Assumptions for Society Business and Work / [ed] Hans Christian Garmann Johnsen, Halvor Holtskog and Richard Ennals, London & New York: Routledge, 2018, p. 187-200Chapter in book (Other academic)
  • 26.
    Evegren, Adam
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Utveckling av återkopplad motormodul för styrning av mätantenn: En fallstudie hos företaget Combitech AB2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med föreliggande studie är att undersöka vilket motoralternativ som lämpar sig bäst för precis positionsstyrning av särskilda mätantenner, samt hur denna motor skall kunna drivas på ett funktionellt vis. Huvudresultatet som vill uppnås genom detta projekt är en generell motormodul kapabel att styra antennernas olika dimensioner utifrån användarens kommando genom seriell kommunikation från en PC. Studien har genomförts i samarbete med företaget Combitech AB.

  • 27.
    Fagerqvist, Gustaf
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Integrering av DSP i talförstärkaren MMT-42010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes how to integrate a digital signal processor (DSP) in the speech amplifier MMT-4. This is to improve the sound quality and prevent feedback. Much of the task consisted of selecting a suitable DSP design and components to get it work as a standalone processor in MMT-4. Following this report gives the reader an introduction how to design systems with a DSP and a full description of the DSP ADAU1701.

  • 28.
    Ferreira, Joao Pedro
    et al.
    University of Minho, Portugal.
    Sousa, Marta Noronha
    University of Minho, Portugal.
    Branco, Nuno
    University of Minho, Portugal.
    Ferreira, Manuel Joao
    University of Minho, Portugal.
    Otero, Nuno
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics. University of Minho, Portugal.
    Zagalo, Nelson
    University of Minho.
    Branco, Pedro
    University of Minho, Portugal.
    Thin slices of interaction: predicting users' task difficulty within 60 sec2012In: Proceedings CHI '12 Extended Abstracts on Human Factors in Computing Systems, ACM Press, 2012, p. 171-180Conference paper (Refereed)
    Abstract [en]

    We report on an exploratory study where the first 60 seconds of the video recording of a user interaction are used to predict the user’s experienced task difficulty. This approach builds on previous work on “thin slices” of human-human behavior, and applies it to human- computer interaction. In the scenario of interacting with a photocopy machine, automated video coding showed that the Activity and Emphasis predicted 46.6% of the variance of task difficulty. This result closely follows reported results on predicting negotiation outcomes from conversational dynamics using similar variables on the speech signal.

  • 29.
    Fransson, David
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Projektering av elkraftanläggning för fläktprov: dimensionering av transformator, kablar mm2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Fläkt Woods har ett fläktlab i Växjö där man utför kund och leveransprover av axiella fläktar.

    Befintlig anläggning är i dag bristfällig när det gäller driftsäkerhet och personsäkerhet. Även möjligheten att köra varvtalsreglerat är idag begränsad.

    Uppgiften är att projektera en ny anläggning omfattande en ny jordkabel, mellan- och lågspänningsställverk, transformatorer, kopplingsutrustningar och frekvensomriktare.

  • 30.
    Fransson, Kim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Nya användningsområden KUL2007Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    KUL-KontrollUtrustning Luftvärn används för verifieringar på modifierade och nya luftvärnssystem. Utrustningen har varit begränsad till att kunna verifiera luftvärnssystem och denna rapport är en undersökning som ser på om det finns andra områden där man skulle kunna använda utrustningen. I rapporten beskrivs svensktluftvärn i stort för att kunna förstå hur KUL används. Rapporten går igenom KUL och dess utrustning och egenskaper sen går den igenom olika förslag på områden där KUL skulle kunna användas samt problem och behov av modifikation på KUL för det aktuella området. I rapporten ingår även en sammanfatningar på de studier som har gjorts för att kunna förstå problematik runt utrustningen som t.ex. alla olika format och kommunikationssystem.

  • 31. Golub, Koraljka
    et al.
    Knok, Željko
    Mogućnosti primjene XML-a na sustave za predmetno označavanje2013In: Zbornik radova Međimurskog veleučilišta u Čakovcu, ISSN 1849-1138, Vol. 4, no 1, p. 21-27Article, review/survey (Refereed)
  • 32. Golub, Koraljka
    et al.
    Knok, Željko
    Standard metapodataka za znanstvene podatke CERIF u implementaciji XML-a2013In: Zbornik radova Međimurskog veleučilišta u Čakovcu, ISSN 1849-1138, Vol. 4, no 2, p. 49-54Article, review/survey (Refereed)
  • 33.
    Gran, Erik
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Hård, Erik
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Utveckling av koncept för att reglera reaktiv effekt vid generatordrift via PLC: Framtagande och provning av prototyp2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project investigates the possibilities of being able to control a generators reactive power production by controlling the excitation current from a PLC. As a method for controlling from PLC, it was decided that a signal of 0-5V should be used. In order to regulate the magnetization, and hence in the long term the reactive power, it was decided that the existing manual potentiometer would be replaced by two parallel-connected digital potentiometers of the type MCP4261 controlled by a microcontroller. The fact that the digital potentiometers would be connected in parallel was decided after a feasibility study which showed that in this way it would result in a more accurate regulation without any restriction on the usable control span. Practical testing of microcontrollers and digital potentiometers provided a satisfactory result with a good resolution.

  • 34.
    Granlund, Peter
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Stenström, Anton
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Landström: Undersökning av svenska hamnars ekonomiska möjligheter att investera i landströmsteknik2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study was to investigate Swedish ports possibility to invest in onshore power supply equipment and pay back the initial investment with income from selling electricity to arriving ships. The study is a systematic review based on a sys­tematic search and presented as a theoretical case study. The review was based on five studies that describe costs of providing a port with onshore power supply.

     

    The first part of the findings is calculations of the investment cost for onshore power supply for one single berth. Next the calculations of the costs to generate a certain amount of electricity on board was compared with the costs of buying said amount of electricity from shore providers. Then a profit margin if the electricity was sold for the same price as it would have cost to generate onboard in diesel generators was calculated. Finally the in­crease to the electricity sale price a port could add and still repay the initial investment over five years was calculated. This electricity sale price was then compared to what it would have cost to generate onboard.

     

    The findings shows that there is a good possibility for the theoretical standard quay to refund their investment in onshore power supply over five years, under circumstances where ships visiting the port are equipped to receive the electricity. 

  • 35.
    Gustafsson, Josefin
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Andersson, David
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Detektering av föremål med hjälp av beröringsfria sensorer2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Uppgiften är att föreslå olika metoder på ett kollisionskydd som företaget Arcoma kan använda sig av. Skyddet skall i första hand kunna detektera en människa men om möjligt även döda föremål. Skyddet skall kunna sitta på Arcomas olika röntgenstativ och bord.

    Ett utvärderingskort från Freescale undersöktes först. Kortet skapar ett elektromagnetiskt fält mellan valda utgångar och frågan är om man kan detektera ifall detta fält bryts av något föremål.

    Eftersom utvecklingskortet inte fungerade bra riktades blickarna mot andra tänkbara lösningar. Den lösning som verkade mest gångbar var att använda sig utav kapacitiva sensorer. Ett testkort som kan drivas av röntgenutrustningens 24V matning konstruerades. Kortet jämför två stycken spänningsnivåer där den ena kommer från en fast likspänning och den andra ursprungligen kommer från en pulsgenerator. Pulsgeneratorn ger ifrån sig en fyrkantspuls på cirka fem kHz, efter pulsgeneratorn sitter en kapacitans bestående av två stycken metalliska ytor. Beroende på avståndet mellan sensorplattorna ökar eller minskar kapacitansen, om ett föremål närmar sig förändrar kondensatorns dielektrikum och en spänningsförändring fås. Efter sensorn förstärker en operationsförstärkare den låga spänningen. Nästa steg är att jämföra den fasta likspänningen med spänningen från sensorn. När ett föremål närmar sig sensorn sjunker spänningen och nivån blir lägre än den fasta likspänningen. Då detta händer ändras komparatorkretsens utspänning från 0 – 12V eller tvärtom beroende på insignalernas koppling till komparatorn. En lysdiod fungerade som spänningsindikator.

    Efter en rad tester och demonstrationer verkade företaget mycket intresserade av att fortsätta arbeta med denna metod och kanske utveckla en ny produkt baserad på denna.

  • 36.
    Gustafsson, Stefan
    et al.
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Nilsson, Börje
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Nordebo, Sven
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Sjöberg, Mats
    ABB AB, Karlskrona, Sweden.
    Wave propagation characteristics and model uncertainties for HVDC power cables2015In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 30, no 6, p. 2527-2534Article in journal (Refereed)
    Abstract [en]

    This paper presents a stable and efficient fullwave cable model and a detailed study of the relatedmodel uncertainties regarding the wave propagation characteristics of very long HVDC power cables at low frequencies. The model can be used to predict the dispersion characteristics of the cable with respect to its electromagnetic parameters, or as an inverse problem to estimate some parameters of the cable (armour permeability, metal layer conductivities, temperature, length, etc.) based on measurements. The electromagnetic model is based on a magnetic frill generator that can be calibrated to the current measured at the input of the cable, and a layer recursive computation of the axial-symmetric fields. Measurements of pulse propagation on an 82 km long HVDC power cable over a bandwidth of 100 kHz have been used to validate the model. The main conclusion of the study is that the conductivity (and thus the temperature) of the conductor and the lead sheath are of utmost importance to achieve an accurate model. At the same time, some parameters are in principle insignificant regarding the dispersion characteristics in the low-frequency regime, such as the permittivity and the conductivity of the semi-conducting screens. The paper contains an investigation and a discussion on the electromagnetic properties of all layers of a typical HVDC power cable.

  • 37.
    Gustafsson, Stefan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Nordebo, Sven
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Nilsson, Börje
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Electromagnetic dispersion modeling and sensitivity analysis for HVDC power cables2012Report (Other academic)
    Abstract [en]

    This paper addresses electromagnetic wave propagation in High Voltage Direct Current (HVDC) power cables. An electromagnetic model, based on long (10 km or more) cables with a frequency range of 0 to 100 kHz, is derived. Relating the frequency to the propagation constant a dispersion relation is formulated using a recursive approach. The propagation constant is found numerically with normalized residue calculation. The paper is concluded with a sensitivity analysis of the propagation constant with respect to the electrical parameters εr (the real relative permittivity) and σ (the conductivity)

  • 38.
    Gustavsson, Ingvar
    et al.
    Blekinge Institute of Technology.
    Claesson, Lena
    Blekinge Institute of Technology.
    Nilsson, Kristian
    Blekinge Institute of Technology.
    Zackrisson, Johan
    Blekinge Institute of Technology.
    Garcia, Javier Zubia
    University of Deusto, Spain.
    Hernandez, Jayo Unai
    University of Deusto, Spain.
    Håkansson, Lars
    Blekinge Institute of Technology.
    Ström Bartunek, Josef
    Blekinge Institute of Technology.
    Lagö, Thomas
    Blekinge Institute of Technology.
    Claesson, Ingvar
    Blekinge Institute of Technology.
    Chapter 15 – The VISIR Open Lab Platform2011In: InternetAccessible Remote Laboratories: Scalable E-learning Tools for Engineering and Science Disciplines / [ed] M. E. Auer, V. J. Harward and A. K. M. Azad, IGI Global, 2011, p. 294-317Chapter in book (Refereed)
    Abstract [en]

    The VISIR Open Lab Platform designed at the Department of Electrical Engineering (AET), the Blekinge Institute of Technology (BTH), Sweden, is a platform for opening instructional laboratories for remote access 24/7 with preserved context. VISIR is an acronym for Virtual Instrument Systems in Reality. In VISIR laboratories, students perform physical experiments and laboratory work remotely. A unique interface gives them the feeling of “being there.” The platform software is published under a GPL license, and other universities, schools, et cetera, are invited use it to open their laboratories and to participate in further research and development. Apart from BTH, five universities in Europe have set up VISIR online laboratories for electrical experiments and the Indian Institute of Technology Madras in India will set up one soon. A VISIR community has been established. Common projects are initiated, and the sharing of learning material is being discussed. This chapter is a general introduction to VISIR and its possibilities.

  • 39.
    Gustavsson, Ingvar
    et al.
    Blekinge Institute of Technology.
    Nilsson, Kristian
    Blekinge Institute of Technology.
    Zackrisson, Johan
    Blekinge Institute of Technology.
    Garcia-Zubia, Javier
    University of Deusto, Spain.
    Hernandez-Jayo, Unai
    University of Deusto, Spain.
    Nafalski, Andrew
    University of South Australia, Australia.
    Nedic, Zorica
    University of South Australia, Australia.
    Göl, Özdemir
    University of South Australia, Australia.
    Machotka, Jan
    University of South Australia, Australia.
    Pettersson, Mats
    Blekinge Institute of Technology.
    Lagö, Thomas
    Acticut International AB, Falkenburg.
    Håkansson, Lars
    Blekinge Institute of Technology.
    On objectives of instructional laboratories, individual assessment, and use of collaborative remote laboratories2009In: IEEE Transactions on Learning Technologies, ISSN 1939-1382, E-ISSN 1939-1382, Vol. 2, no 4, p. 263-274Article in journal (Refereed)
    Abstract [en]

    Three key issues should be addressed to enable universities to deliver engineers who have a solid documented laboratory experience enabling them to design goods and services complying with the requirements of a sustainable society. First, introduce learning objectives of engineering instructional laboratories in courses including laboratory components. Second, implement individual student assessment. Third, introduce free access to online experimental resources as a supplement to the equipment in traditional laboratories. Blekinge Institute of Technology (BTH) in Sweden and the University of South Australia (UniSA) have created online laboratory workbenches for electrical experiments that mimic traditional ones by combining virtual and physical reality. Online workbenches not only supplement traditional ones, but they can also be used for low-cost individual assessment. BTH has started a project disseminating the BTH workbench concept, The Virtual Instrument Systems in Reality (VISIR) Open Laboratory Platform, and invites other universities to set up replicas and participate in further development and standardization. Further, online workbenches offer additional learning possibilities. UniSA has started a project where students located in different countries can perform experiments together as a way to enhance the participants' intercultural competence. This paper discusses online laboratory workbenches and their role in an engineering education appropriate for a sustainable society.

  • 40.
    Gustavsson, Ingvar
    et al.
    Blekinge Institute of Technology.
    Zackrisson, Johan
    Blekinge Institute of Technology.
    Håkansson, Lars
    Blekinge Institute of Technology.
    Chapter 11 – A new Concept for Distributed Laboratories Based on Open Source Technology2007In: Advances on remote laboratories and e-learning experiences / [ed] L. Gomes and J. Garcia-Zubia, Deusto Publicaciones , 2007, p. 247-267Chapter in book (Refereed)
  • 41.
    Hallenfors Johansson, Maxim
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Färlind, Filip
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Ottosson, Kim
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Processorbelastning med MPLS och IP-routing2013Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This paper was based on the thesis "MPLS kontra traditionell IP routing - enjämnförelse av resursåtgång" by Sebastian Viking and Anton Öhlin. Their workcompared the CPU usage when performing routing with, and without, MPLS. Theresults demonstrates that MPLS provides higher processor load over traditional IProuting, contrary to the theory of MPLS. Due to the apparent contradictions betweentheory and practice has this work intended to create a hypothesis examined deductivelywith the aim to confirm its statement: Because of MPLS, and IP's, implementation ofthe underlying hardware architecture should no noticeable difference in processor usagebe presentated at tests where a router's job is to convey the package. Therefore, we recreatedtheir tests to confirm the authenticity of their results. The results from the testsin this paper showed no significant difference between IP routing technologies withCEF, and MPLS. Presented results thus confirm the hypothesis supported by thetheories behind the techniques used.

  • 42.
    Hamon, Camille
    et al.
    KTH Royal Institute of Technology.
    Perninge, Magnus
    KTH Royal Institute of Technology.
    Söder, Lennart
    KTH Royal Institute of Technology.
    A computational framework for risk-based power system operations under uncertainty: Part II: Case studies2015In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 119, p. 66-75Article in journal (Refereed)
    Abstract [en]

    With larger penetrations of wind power, the uncertainty increases in power systems operations. The wind power forecast errors must be accounted for by adapting existing operating tools or designing new ones. A switch from the deterministic framework used today to a probabilistic one has been advocated. This two-part paper presents a framework for risk-basedoperations of power systems. This framework builds on the operating risk defined as the probability of the system to be outside the stable operation domain, given probabilistic forecasts for the uncertainty, load and wind power generation levels. This operating risk can be seen as a probabilistic formulation of the N - 1 criterion. In Part I, the definition of the operating risk and a method to estimate it were presented. A new way of modeling the uncertain wind power injections was presented. In Part II of the paper, the method's accuracy and computational requirements are assessed for both models. It is shown that the new model for wind power introduced in Part I significantly decreases the computation time of the method, which allows for the use of later and more accurate forecasts. The method developed in this paper is able to tackle the two challenges associated with risk-based real-time operations: accurately estimating very low operating risks and doing so in a very limited amount of time.

  • 43.
    Hamon, Camille
    et al.
    KTH Royal Institute of Technology.
    Perninge, Magnus
    KTH Royal Institute of Technology.
    Söder, Lennart
    KTH Royal Institute of Technology.
    A computational framework for risk-based power systems operations under uncertainty: Part I: Theory2015In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 119, p. 45-53Article in journal (Refereed)
    Abstract [en]

    With larger penetrations of wind power, the uncertainty increases in power systems operations. The wind power forecast errors must be accounted for by adapting existing operating tools or designing new ones. A switch from the deterministic framework used today to a probabilistic one has been advocated. This two-part paper presents a framework for risk-basedoperations of power systems. This framework builds on the operating risk defined as the probability of the system to be outside the stable operation domain, given probabilistic forecasts for the uncertainty (load and wind power generation levels) and outage rates of chosen elements of the system (generators and transmission lines). This operating risk can be seen as a probabilistic formulation of the N - 1 criterion. The stable operation domain is defined by voltage-stability limits, small-signal stability limits, thermal stability limits and other operating limits. In Part I of the paper, a previous method for estimating the operating risk is extended by using a new model for the joint distribution of the uncertainty. This new model allows for a decrease in computation time of the method, which allows for the use of later and more up-to-date forecasts. In Part II, the accuracy and the computation requirements of the method using this new model will be analyzed and compared to the previously used model for the uncertainty. The method developed in this paper is able to tackle the two challenges associated with risk-based real-time operations: accurately estimating very low operating risks and doing so in a very limited amount of time.

  • 44.
    Hamon, Camille
    et al.
    KTH Royal Institute of Technology.
    Perninge, Magnus
    KTH Royal Institute of Technology.
    Söder, Lennart
    KTH Royal Institute of Technology.
    A stochastic optimal power flow problem with stability constraints: Part I: Approximating the stability boundary2013In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 28, no 2, p. 1839-1849Article in journal (Refereed)
    Abstract [en]

    Stochastic optimal power flow can provide the system operator with adequate strategies for controlling the power flow to maintain secure operation under stochastic parameter variations. One limitation of stochastic optimal power flow has been that only line flows have been used as security constraints. In many systems voltage stability and small-signal stability also play an important role in constraining the operation. In this paper we aim to extend the stochastic optimal power flow problem to include constraints for voltage stability as well as small-signal stability. This is done by approximating the voltage stability and small-signal stability constraint boundaries with second-order approximations in parameter space. Then we refine methods from mathematical finance to be able to estimate the probability of violating the constraints. In this first part of the paper, we derive second-order approximations of stability boundaries in parameter space. In the second part, the approximations will be used to solve a stochastic optimal power flow problem.

  • 45.
    Hamon, Camille
    et al.
    Norwegian University of Science and Technology, Norway.
    Perninge, Magnus
    Lund University.
    Söder, Lennart
    KTH Royal Institute of Technology.
    An importance sampling technique for probabilistic security assessment in power systems with large amounts of wind power2016In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 131, p. 11-18Article in journal (Refereed)
    Abstract [en]

    Larger amounts of variable renewable energy sources bring about larger amounts of uncertainty in the form of forecast errors. When taking operational and planning decisions under uncertainty, a trade-off between risk and costs must be made. Today's deterministic operational tools, such as N-1-based methods, cannot directly account for the underlying risk due to uncertainties. Instead, several definitions of operating risks, which are probabilistic indicators, have been proposed in the literature. Estimating these risks require estimating very low probabilities of violations of operating constraints. Crude Monte-Carlo simulations are very computationally demanding for estimating very low probabilities. In this paper, an importance sampling technique from mathematical finance is adapted to estimate very low operating risks in power systems given probabilistic forecasts for the wind power and the load. Case studies in the IEEE 39 and 118 bus systems show a decrease in computational demand of two to three orders of magnitude.

  • 46.
    Hamon, Camille
    et al.
    KTH Royal Institute of Technology.
    Perninge, Magnus
    KTH Royal Institute of Technology.
    Söder, Lennart
    KTH Royal Institute of Technology.
    Efficient importance sampling technique for estimating operating risks in power systems with large amounts of wind power2014In: Proceedings of the 13th International Workshop on Large-scale Integration of Wind Power into Power Systems as well as on Transmission Networks for Offshore Wind Power Plants / [ed] Uta Betancourt, Thomas Ackermann, Energynautics GmbH, 2014Conference paper (Refereed)
    Abstract [en]

    Uncertainties faced by operators of power systems are expected to increase with increasing amounts of wind power. This paper presents a method to design efficient importance sampling estimators to estimate the operating risk by Monte-Carlo simulations given the joint probability distribution describing the wind power and load forecasts. The operating risk is defined as the probability of violating stability and / or operating constraints. The method relies on an exisiting framework for rare-event simulations but takes into account the peculiarities of power systems. In case studies, it is shown that the number of Monte-Carlo runs needed to achieve a certain accuracy on the estimator can be reduced by up to three orders of magnitude.

  • 47.
    Hamon, Camille
    et al.
    KTH Royal Institute of Technology.
    Perninge, Magnus
    Lund University.
    Söder, Lennart
    KTH Royal Institute of Technology.
    The value of using chance-constrained optimal power flows for generation re-dispatch under uncertainty with detailed security constraints2013In: 2013 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC), IEEE, 2013Conference paper (Refereed)
    Abstract [en]

    The uncertainty faced in the operation of power systems increases as larger amounts of intermittent sources, such as wind and solar power, are being installed. Traditionally, an optimalgeneration re-dispatch is obtained by solving security-constrained optimal power flows (SCOPF). The resulting system operation is then optimal for given values of the uncertain parameters. New methods have been developed to consider the uncertainty directly in the generation re-dispatch optimization problem. Chance-constrained optimal power flows (CCOPF) are such methods. In this paper, SCOPF and CCOPF are compared and the benefits of using CCOPF for power systems operation under uncertainty are discussed. The discussion is illustrated by a case study in the IEEE 39 bus system, in which the generation re-dispatch obtained by CCOPF is shown to always be cheaper than that obtained by SCOPF.

  • 48.
    Hultgren, Anders
    et al.
    Blekinge Institute of Technology.
    Bui, Sonny
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Linnér, Jörgen
    Alstom Power AB.
    Ranstad, Per
    Alstom Power AB.
    Lenells, Matz
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Fault tolerant high voltage resonant power converter application2013In: Proceedings: 2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives (SDEMPED), IEEE, 2013, p. 485-490Conference paper (Refereed)
    Abstract [en]

    A high voltage and high power fault tolerant application of a resonant converter is presented. The resonant converter load shows frequent short circuits making the load voltage drop to zero within some us, implying high stress on the main circuit components. A load voltage short circuit fault tolerant system is suggested by including a novel way of augmenting the controller with a load voltage estimator. The estimator can detect load voltage short circuit and will then be a part of a fault tolerant high voltage resonant converter.

  • 49.
    Hussein, Ivan
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Minskning av switchförluster vid höga frekvenser i diodbrygga på PCB-kort2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetets huvudmål var att utvärdera Zero Voltage Switching, ZVS, på ett dubbelsidigt kretskort. Där ingick att anpassa en H-brygga till ZVS som är populär i industrier samt elektronikkonstruktion. Mätningarna och analyserna gjordes för båda delarna. Med hjälp av en mikrokontroller kunde man ändra på styrsignalernas Duty Cycle och frekvens.

    Framtagen kretskort har sedan använts till att utföra mätningar vid frånslag där falltider, energiåtgång och switchförluster har jämförts med liknande krets på kopplingssplatta och i simulering.

    Nyckelord: switchförluster, H-brygga, zero voltage switching. 

  • 50.
    Håkansson, Therése
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Avståndsmätning med Hallelement2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Hall effect sensor is a magnetic sensor that is used for different applications. It only works when a magnetic field or electrical current can be found in the vicinity. This work is focused on a specific sensor but also describes how a Hall effect sensor generally are constructed. The specific sensor is used for distance measurement. A variety of tests have been carried out to try to increase the distance at which the sensor can detect.

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