This thesis work contains a litterature study about electrical motors in general and how PWM-patterns for brushless DC-motors can be made. A suitable method has been implemented as a simulation model in VHDL. A simulation model of a brushless DC-motor which describes the phasecurrents, torque and angular velocity has also been made. The motor model made simulations easier for the complete PWM-system. The design was synthesised and tested with a prototypeboard including a SPARTAN II FPGA.

In today?s society, safety in a workplace is an important factor to any organization. Focus on improving the working conditions by making them safer through technology is taking us into a time where we rely on technology to keep us safe. How well developed the technology may be, it is still not enough to keep us entirely from harm. Human error will always be a factor in the human interaction with a workplace.

This thesis is a part of the project "Sustainable harvesting and storage of sugar beets, more sugar to practice". The work has included a large part of practical experimental work with weight measurement, graduation and storage planning. The aim of the project is to be able to see whether the cultivars react differently in different storage conditions. The project has included storage under controlled conditions to give as accurate results as possible. To be able to mimic the farmers own preconditions the samples was harvested with a conventional Holmer.This project has two parts, one concerning the nature, time and temperature on storage where a number of different cultivars where investigated during three different recording times, two different temperatures and controlled in a controlled environment.

At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause the valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark..

The purpose of this thesis is to assist the Swedish energy company NIBE Energy Systems in their studies of adaptive regulation applicable to electrical water heaters. Due to coming energy classifications of these appliances in the European Union, NIBE Energy Systems needs to use adaptive regulation, called Smart Control, to keep their products in the best possible energy class and remain competitive to the market. By using this Smart Control regulation a 2-3 % improve-ment of efficiency can be credited the system. This is a small number, but heavily needed, since the energy classes are based on the idea that the European Union is provided with electricity from coal condensate power resulting in a 40 % maximum efficiency. Furthermore, doing noth-ing will result in some water heaters not being approved to use on the market from 2015 due to low efficiency.

This thesis considers the use of an oldrock cavern as thermal energy storage.With a large system of differentchillers a model was created to find anappropriate future system. There aremainly two trajectories to take. Eitheran installation of chillers needs to bemade or the rock cavern can be used tomeet the future demand of districtcooling in Solna, Sweden. Additionallythis thesis investigates the possibleuse of different techniques to utilizethe phase change energy of water.Simulation shows that it?s possible toutilize the phase-change energy of afluid; however it?s not economicallyfeasible due to the thermodynamiceffects on the Carnot cycle.

Orust Kretsloppsakademi is a nonprofit organisation, with a goal of annually generate the same amount of electrical energy that is consumed. Orust is an island on the west coast of Sweden, north of Gothenburg. The population of 15 000 reaches 40 000 during summer, due to the large amount of vacationer. The total electricity demand is 174 GWh a year with a maximum power need of 32 MW. This report presents an analysis for the plausibility of their plan and from a power system stability perspective, the effects on the electrical grid.The conclusion is that the restraints for development of power generation from wind, solar and wave generation, are the power systems capability to transfer power, primarily in the transformers of the grid.

Lyckeby Starch AB is a farmer-owned company that produces products based on potato starch. In order to increase their production efficiency and their international competitiveness the company is investigating the possibilities of keeping their factories open longer. To achieve this, potato has to be stored for a longer period of time than what is practiced today. Starch potato is usually stored in large piles covered by straw and plastic, either in the field or on the farmyard. The objective was to examine in what way starch yield (starch content*tuber weight) in three different potato varieties was affected by storage in two different types of storage piles. The potato was stored for three months in total and starch content and tuber weight were controlled throughout the period. Stored tubers were also visually examined and prescense of mechanical damage as well as wet rots and dry rots was recorded. Bacteria and fungi were isolated and identified. In general, varietal differences were greater than differences between the storage piles.

The Goal with this Master of Science thesis is to expand the possible turbine efficiencymeasurements on an exhaust turbocharger. It was done as a part of the CICERO competencecentre. To feed the turbine with air a special flow rig has been used. Instead of loading theturbine by just restricting the compressor flow a docking system for an electrical dynamometer isdesigned to use the dynamometer as an additional loading source. By using an electricaldynamometer as loading device for the turbine, measurements are not depending on compressorperformance.A large part of the work consists in designing accessories for the dynamometer.

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

Allt eftersom webben utvecklas kommer det nya tekniker och verktyg att lära sig för webbutvecklare. WebStorage är en av dessa. Som en del av HTML5 har den många användbara funktioner som öppnar upp nyamöjligheter för utvecklare och för vad webben kan användas till. Som plattform har en hemsida som gåttunder projektnamnet Partify använts och här har Web Storage testas att användas för att undersöka hurman bäst använder tekniken. Rapporten innehåller ingående fakta om hur Web Storage är uppbyggt ochhur man använder det.Efter jämförelse med dagens vanliga teknik, cookies, finns tydliga resultat på hur väl Web Storage hävdarsig när det gäller säkerhet, prestanda, användarvänlighet och funktionalitet.

The need for a more efficient electrical grid has made the smart grid concept popular in recent years. The aims of this study are to identify the conditions in Sweden for implementing a smart grid and to analyse the opinions of stakeholders. One finding is that the large capacity of Sweden?s existing electrical grid decreases the immediate need for smart grid solutions. However, the rapid increase in wind power might push the development of a smart grid in the coming years.

Sweden has long had access to low electricity prices due to the wide availability of hydro and nuclear power. This has now changed because of today's rising electricity rates resulting in increasing heating costs for properties, especially in the properties with electric heating systems."Ankaret" is a parish for "Svenska Alliansmissionen", which is located at "Gullbrannagården".The parish has installed electrical radiators and an exhaust ventilation system that makes the energy demand high due to the large ventilation flows. The building was built as the price of electricity was still low and would reduce energy use today by combining its heating system with an air/air heat pump. The heat pump delivers more heat into the room than the electrical energy that it uses. This lowers the electricity needs.

When the Swedish Forestry Act was changed in 1994, brushing of young stands became non mandatory. Since then the annual need for brushing in the country has increased by about 100 000 hectares per year. In later years the price for biomass energy has increased to the same level as pulp wood. The high price on biomass energy and the large areas of stands in the need of brushing has created a new market with its own technical, economical and environmental conditions. There is a development of various techniques to manage the forestry stands with late brushing.

Geothermal energy can be extracted from an aquifer, where the groundwater is used as heatexchange medium while heat and cold are stored in the surrounding material in the aquiferand to some extent in the groundwater. Application of aquifer storage for the use ofgeothermal energy is mainly used in large scale facilities and is limited to sites with suitableaquifers in the form of ridges, sandstone and limestone aquifers.Löwenströmska hospital in the municipality of Upplands Väsby, north of Stockholm, islocated nearby the northern part of the Stockholm esker. This means that it can be profitableand environmentally beneficial for the hospital to examine the possibilities of aquifer storagein the esker material next to its property.The purpose of this master thesis has been to investigate if geothermal energy storage with aseasonal storage of heat and cold can be applied within Löwenströmska hospital?s propertyarea using groundwater modeling. A hydraulic groundwater model was constructed inMODFLOW based on a simplified conceptual model of the groundwater system.