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.

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.

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 20^o 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.

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.

Mikronät är ett självförsörjande elnät och används bland annat då elektriskaprodukter kräver en AC-spänning men inte har tillgång till huvudnätet. Målet idetta projekt är att dimensionera och analysera de olika delarna som ett mikronätbestår av, för att sedan konstruera och testa ifall den uppfyller kraven utifrånvissa specifikationer.Metoderna som används för att dimensionera och analysera mikronätet bestårfrämst av beräkningar och simuleringar samt konstruktion av enstaka kretsar.Mikronätet består av en AC-drive, ett lågpassfilter och trefastransformator.Mikronätet konstrueras med en varierbar frekvens mellan 45 och 65 Hz, samtomvandling av 540 VDC till 400 VAC.

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.

Effective heat management is essential for preserving performance and dependability as electronic equipment becomes increasingly powerful and smaller. This project presents the developed system, TeRMeS, which was created to test the thermal resistance of thermal interface materials (TIMs) essential for the thermal management of electronic devices, including battery systems. This work focuses on using steady-state techniques to evaluate TIMs under various operational forces and temperatures in real-world electronic packaging conditions.

A noteworthy breakthrough is the creation of a user-friendly graphical user interface (GUI), which offers sophisticated options for real-time thickness measurement and enables researchers to alter parameters and dynamically display outcomes, thereby improving the measuring process.

The results of the experiment highlight the importance of TIM thickness and applied force in lowering thermal resistance and increasing thermal conductivity. These elements are necessary to prevent battery packs and electrical parts from overheating. To improve heat management strategies in high-performance computing and electronics, the study provides accurate, reliable data by focusing on steady-state measurements.

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. 

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.

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

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.

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.

The increasing penetration of wind power into the power system dominated by variable-speed wind turbines among the installed wind turbines will require further development of control methods. Power electronic converters are widely used to improve power quality in conjunction with the integration of variable speed wind turbines into the grid. In this thesis, a detailed model of the Predictive Current Control (PCC) method will be descripts for the purpose of control of the grid-connected converter. The injected active and reactive power to the grid will be controlled to track their reference value. The PCC model predicts the future grid current by using a discrete-time model of the system for all possible voltage vectors generated by the inverter. The voltage vector that minimizes the current error at the next sampling time will be selected and the corresponding switching state will be the optimal one. The PCC is implemented in Matlab/Simulink and simulation results are presented. 

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.

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.

Detta arbete inleds med en översiktlig teoretiskt bakgrund om analog till digital-omvandlare(A/D-omvandlare). Vartefter arbetet beskriver två kända metoder för att transformera återkopplingsloopar konstruerade i den tidsdiskreta z-domänen till den tidskontinuerliga Laplace-domänen. En simulering genomfördes för att visa hur en av dessa metoder gav en förväntadbrusformning.

Mätning av brus med diskret Fouriertransform beskrivs och en modell av en inkrementellsigma-delta A/D-omvandlare simuleras för att visa hur en enkel räknare kan användas i deci-meringen.

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.

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.

The educational phenomena studied in this paper is remote-controlled physical laboratory environments and their applicability in upper secondary school physics education. In order to gain a better understanding of the situation and needs regarding laboratory activities in the upper secondary school, eight physics teachers were interviewed at six different schools. This revealed that the resources for laboratory activities vary between schools and may be inconsistent with the Swedish National Agency for Education curriculum. Furthermore, 165 upper secondary school students answered a questionnaire survey regarding subject preferences, program choices, views on technology and self-ability, and approach to technology and technology-related situations. The acquired knowledge provides a basis concerning the needs and conditions of teaching and learning within the subject of physics. This new knowledge motivates the development of the Flipped laboratory concept that is introduced in this paper, based on remote-controlled physical laboratories, for upper secondary school.

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.

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.

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.

It is commonly agreed among energy experts that smart meters (SMs) are the key component that will facilitate the transition towards the smart grid. Fast-peace innovations in the smart metering infrastructure (AMI) are exposing countless benefits that network operators can obtain when they integrate SMs applications into their daily operations. 

Following the amendment in 2017, where the Swedish government dictated that all SMs should now include new features such as remote control, higher time resolution for the energy readings and a friendly interface for customers to access their own data; network operators in Sweden are currently replacing their SMs for a new model, also called the second generation of SMs. While the replacement of meters is in progress, many utilities like Hemab are trying to reveal which technical and financial benefits the new generation of SMs will bring to their operations.   

As a first step, this thesis presents the results of a series of interviews carried out with different network operators in Sweden. It is studied which functionalities have the potential to succeed in the near future, as well as those functionalities that are already being tested or fully implemeneted by some utilities in Sweden. Furthermore, this thesis analyses those obstacles and barriers that utilities encounter when trying to implement new applications using the new SMs.

In a second stage, an alarm system for power interruptions and voltage-quality events (e.g., overvoltage and undervoltage) using VisionAir software and OMNIPOWER 3-phase meters is evaluated. The results from the evaluation are divided into three sections: a description of the settings and functionalities of the alarm, the outcomes from the test, and a final discussion of potential applications.

This study has revealed that alarm functions, data analytics (including several methods such as load forecasting, customer segmentation and non-technical losses analysis), power quality monitoring, dynamic pricing, and load shedding have the biggest potential to succeed in Sweden in the coming years. Furthermore, it can be stated that the lack of time, prioritization of other projects in the grid and the integration of those new applications into the current system seem to be the main barrier for Swedish utilities nowadays. Regarding the alarm system, it was found that the real benefits for network operators arrive when the information coming from an alarm system is combined with a topology interface of the network and a customer notifications server. Both applications could improve customer satisfaction by significantly reducing outage time and providing customers with real-time and precise information about the problems in the grid.

Motivated by the need for less polluting energy production, the recent increase in renewable electricity production is reshaping classical power systems. Initially unidirectional and constant power flow becomes multi-directional and dynamic. As one of the many consequences, classical power system fault location methods might become outdated.To this extent, the development of new methods as well as improvement of already existing methods is of great interest. Additionally, robust and fast means of fault location strengthen power system reliability by improving recovery time. Since most of the faults occur at the distribution level, a study of the main fault location methods in distribution power systems is first conducted. Relevant information about their respective advantages and drawbacks put into light the need to improve classical fault location methods or to develop new methods. The main objective of the thesis is to develop a prototype data-driven ground fault location method that aims to improve the robustness and accuracy offault location in the power system, as well as offer new solutions for fault location.

An 11-bus 20 kV distribution power system with distributed generation is modeled to test the method. As a requirement for data-driven methods, the dataset is provided through simulation where time-domain three-phase voltages at the system substation during fault are generated. This data is then processed using dyadic discrete wavelet transform, a powerful signal processing method, to extract useful information of the signal, after what relevant features are found from the wavelet coefficients. To predict the location ofthe fault, neural networks are trained to find potential correlations between computed features and the distance of the fault from the substation. After testing and comparing different combinations of neural networks, results are analyzed, and eventually, challenges and potential improvements for further development and application of the method are introduced.

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.

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.

Arbetet utfördes med hjälp av Micropower groups i Växjö. För att få ett förståelse för hur Micropowers batteriladdare beter sig och hur stora övertoner de skapar. Då 5 kW laddaren ej klarade SS-EN IEC 61000-3-12[1] standarden, konstruerades det passiva filter för att reducera övertonerna. Det paralleldämpade filtret klarade att reducera dessa övertoner till rätt nivå.

26 KW laddaren klarar standarden, men det lånades in ett elektroniskt filter av Comsys. Filtret testades för att reducera övertoner till den bästa nivån i standarden och hur många laddare filtret kan hantera. Efter detta gjordes det en enkel beräkning för att se hur stor ekonomisk vinst det är på att införskaffa ett filter istället för att bygga individuella filter för varje laddare. 

Nyckelord: Batteriladdare, Filter, Övertoner, Passivt filter, Elektroniskt filter.

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.

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.

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.

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.

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.

Nowadays, interactive visualizations have been one of the most used tools in Big Data fields for the purpose of searching for relationships and structured information in large datasets of unstructured information. In this project, these tools are applied to extract structured information from students following Self-Regulated Learning (SRL). By means of an interactive graph, we are able to study the paths that the students follow in the learning materials. Our visualization supports the investigation of patterns of behaviour of the students, which later could be used, for example, to adapt the study program to the student’s needs in a dynamic way or offer guidance if necessary.

This conclusion presents some closing thoughts on the concepts covered in the preceding chapters of this book. The book addresses the changes, that are likely to come and that will influence society, business and work. It discusses different ways of building knowledge about social and economic change. The book also discusses the special role of social science in providing valid knowledge for the future. It shows that the approach to the issues would be practical and organisational, methodological and philosophical. The innovation discourses in national debates, as well as in the European Union and international organisations, have provided arguments for increased globalisation and market-driven development. They assume that the past is a reliable guide to the future. However, the discourse has been insufficient in its handling of comprehensiveness and inter-relatedness of social and economic change. Those with a focus on technology may have neglected basic human issues; those who focus on sustainability often neglect social and political organisation.

Coping with the Future has been written in response to widespread international awareness that the future is not predictable. In political and economic terms, we are in unknown territory, with daily developments around Brexit and the Trump Presidency, and “Kodak moments” in business. On the other hand, business leaders demand certainty, which is not available. This book redefines the nature of modern business. In contrast to recent trends, it has a focus on human-centred manufacturing and on decision-making which goes beyond a focus on short-term profit. The liberal capitalism of the USA and the UK is not the only current variety of capitalism. Business is not just about managers, but requires participation and engagement by workers. Since the financial crash of 2008, there has been much talk about the need for fresh approaches to business, but little has changed. This book pulls together current research and practice and poses new questions based on case studies. There is no one simple best way, but an uncertain future can be addressed, drawing on diverse past experience and cases. The book addresses an intended audience in business and universities, including business schools, around the world. The debate takes a broader approach, involving research in the social sciences and approaches from philosophy. The world has always been unpredictable, but we have allowed ourselves to be comforted by convenient myths. It is time to wake up. 

Coping with the future is about the ability to anticipate, prepare for, and handle disruptive changes. This chapter argues that there is a big difference between coping with a future within an existing order, compared with a future facing systemic change. It also argues that in any period of systemic change one has to choose direction, and some choices turn out to be better than others. Most people would like to see changes that represent progress but not changes that create fear or conflict or reduce welfare and peaceful social interaction. Social science is concerned with studying the society we live in, and it is part of this society and reality. Science in general, and social science especially, is in a double position when it is seen as part of social development. The nature of Gestalts is different in social science compared to natural science. The chapter also presents an overview of this book.

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.

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. 

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.

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.

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 ε_r (the real relative permittivity) and σ (the conductivity)

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.