This master thesis has been performed at Vattenfall Power Consultant in Gothenburg and Trollhättan for Vattenfall Vattenkraft. In this report vacuum circuit breaker in small-scale hydropower stations with the rated power 4 MVA and below has been studied. Models of the stations are modeled and analyzed in PSCAD/EMTDC to study the high voltage transients that are created after current chopping with vacuum circuit breaker. Vacuum circuit breaker may chop the current before it reaches zero value, which means that high voltage transients can be created. The equipment of the stations can be destroyed by high voltage transients.The purpose of this thesis is to examine the use of vacuum circuit breaker in small-scale hydropower stations and the risk for high voltage transients from current chopping.According to the results there is a risk of high voltage transients after current chopping with small synchronous generators in stations with the operating voltages 0.4 kV and 3.6 kV.

The purpose of this thesis is to investigate if vacuum insulation panels are a competitive alternative to traditional insulation.Vacuum insulation has been used as insulation in buildings in Germany and Switzerland for a few years. In Sweden the high-performance insulation material is mainly used in refrigerators, freezers and vacuum thermoses. The development is proceeding well and vacuum insulation is becoming more common in the construction industry. Since it is a relatively unexplored material on the market there are many flaws and problems with the material.The questions we have chosen to answer in this report include an increased knowledge of vacuum insulation, various problems that may arise when handling/installation and the pros and cons of vacuum insulation compared to standard traditional insulation.The methods we have chosen to use in this report is a literature study, interviews with various suppliers and manufactures and calculations to show the differences between traditional and vacuum insulation. Vacuum insulation is 5-10 times better insulation than standard traditional mineral wool insulation, mainly at the beginning of its lifetime.Vacuum insulation panels (VIP) have a service life of approximately 50 years, whereas traditional insulation has a service life of approximately 100 years.

This rapport is result of a project. The purpose of which was to design a circuit that is used in a heat glove. The heat glove is the technical aid which provides heat inside a glove.It is specially suited for old people who have problems with cold hands because of decreased blood circulation.There already was an old circuit in the glove that gives a constant current which develops heat from battery to glove through a circuit. The temperature is between 32 and 34 degrees.The problem with the existing circuit was to regulate the temperature. There is only on/off switch and there is no way to adjust desirable value of the temperature.In order to solve the problem the old circuit was investigated.

Storing kinetic energy in a flywheel allows for more efficient driving of electricvehicles. Research in this area is in progress at Uppsala University, where a flywheelwith magnetic bearings encased in a vacuum chamber is being constructed. To makethis possible methods for measuring the current through the electromagnets in thebearings and temperatures in the flywheel need to be developed. This has been thepurpose of this report. The current measurement resulted in a resistive method, andthe implementation of eight measurement circuits in the system.

How can a vacuum cleaner motivate you to use it? From a sustainability perspective,the author asked the question of how such a solution would looklike? These where issues that the project tackled and devised solutions for. Theproject wanted to explore the physical modeling and a large part of the finalresult consisted of a full scale model. The project found that the problem ofvacuuming largely consisted of the problem of storage the product. The projectfound that the motivation for the job, therefore, could be resolved by a betterdesigned vacuum cleaner with a built-in hose, folding handles, which couldbe stored integrated within the vacuum cleaner.

In this report we describe an adaptive simulated annealing method for sizing the devices in analog circuits. The motivation for use an adaptive simulated annealing method for analog circuit design are to increase the efficiency of the design circuit. To demonstrate the functionality and the performance of the approach, an operational transconductance amplifier is simulated. The circuit is modeled with symbolic equations that are derived automatically by a simulator..

The purpose of this thesis has been todesign an electric circuit that measurestemperature in three different ways. Asoftware was also designed to record andanalyse the measurments. The result of thecircuit was a PCB with inputs for 42sensors of both surface and non-surfacemeasurments. These all have a maximumerror of ±3°C..

This thesis has been carried out in autumn 2009 at Uppsala University for Boliden Mineral AB. Physical modelling has been used to model a comminution circuit. The model has then been linked to a PLC.When a concentrator is about to become operational Boliden Mineral AB have been looking for a way to test the PLC. The purpose of this report has therefore been to develop models for the subprocess in a concentrator and link these models to the PLC. The subprocess was a comminution circuit in Aitik36.

Uppsala University is involved in a large international collaborationto build the Laser heater system for the European Xray Free-electronlaser in Hamburg, Germany. In this thesis I describe a laser incouplingdevice into the vacuum chamber of this laser heater all the way fromthe specifications to a completed design.The laser heater is a very important part of the XFEL and thepart described here is a part of the vacuum system needed to couplean external laser into the electron vacuum system and align it withthe electron bunches in order to heat them. The task was started by studying the literature about the basic theory andthe design of vacuum systems. After this study and collection of ideaswith colleagues I started to prepare different concepts to solve thetask. The ideas can be put into two categories, in one case the couplingmirror is located inside the vacuum chamber and in the second caseoutside.

Within the ambulance care in Uppsala County a vacuum splint is used to immobilize fractures on extremities. The research available on which method of immobilizing to prefer during pre-hospital treatment is limited. The purpose of this pilot study was to examine the perceptions of the ambulance personal in Uppsala County on the issue of usability of SAM-splint and vacuum splint when immobilizing extremities. The project was also aimed at researching if SAM-splint could be seen as an alternative or a complement to vacuum splint, and to get an apprehension on any evident differences in patients? perceived pain when treated with the two different approaches. A descriptive comparative study was carried out. All patients, regardless of age and sex, with the need of immobilizing supposed fractures, were included.  Patients with suspected femur fracture, collum fracture, or where pre-hospital care was not possible or in question, was excluded.

Within the ambulance care in Uppsala County a vacuum splint is used to immobilize fractures on extremities. The research available on which method of immobilizing to prefer during pre-hospital treatment is limited. The purpose of this pilot study was to examine the perceptions of the ambulance personal in Uppsala County on the issue of usability of SAM-splint and vacuum splint when immobilizing extremities. The project was also aimed at researching if SAM-splint could be seen as an alternative or a complement to vacuum splint, and to get an apprehension on any evident differences in patients? perceived pain when treated with the two different approaches. A descriptive comparative study was carried out. All patients, regardless of age and sex, with the need of immobilizing supposed fractures, were included.  Patients with suspected femur fracture, collum fracture, or where pre-hospital care was not possible or in question, was excluded.

The number of people in the world and the urbanization increases. This leads to a bigger need of space for the built environment, space that soon doesn?t exist. A large portion of humanity?s energy disposal is used for heating of buildings.

The focus of this thesis is primarily in electronic construction and describes the design process for a microcontroller circuit board from concept development to prototyping. The client develops test fixtures for automated testing of products within the electronics industry and needs a new controller circuit for the test fixtures that can handle controls and basic testing. An investigation into the needs of such a system is conducted and a prototype printed circuit board assembly is manufactured.The prototype is developed with focus on protection against electrostatic discharges and overvoltage. Among the functions that are included are voltage measurements, communication interfaces and control of input and output currents. Firmware for the prototype is developed and configured to communicate with a PC through USB interface for control and collecting of measurements..

The last few decades the development in the field of electronics has been huge. The components performance gets better at the same time as the manufacturing cost decreases. Many of the design moments that have to be done, are done automatically today, but it can get better. Especially for analog circuit design.At Electronic System in Linköpings universitet, research is in progress to develop a tool that can design analog circuits in reasonable time. It means that it has to size the components (transistors, resistances, capacitances etc), so that the circuit can fulfill the performance requirements.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.