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11215 Uppsatser om Stand-alone power system - Sida 3 av 748

Ny stamstation i Yttermalung för anslutning av vindkraft : Nätstudie av olika utföranden i normal- och reservdrift

Since 2004, wind power has had the largest installation of new capacity compared to other energy sources in Sweden. Accommodating new wind power may require strengthening or rebuilding of the existing grid in areas where the grid is already loaded to maximum capacity. This master thesis examine the possibility of a new 400/130 kV substation in Yttermalung, Sweden, with a connection to the two neighboring regional grids in Dalarna and Värmland owned by Fortum. This substation would provide a new connection point to the Swedish transmission system as well as an interconnection of the two, currently separated, regional grids. Different expansion scenarios where a substation with and without series compensation or a phase shifting transformer (PST) to control active power flow were studied.

RCC-Jordfelsskydd, mätmodul för övertonsanalys

The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.

Produktivitet och kvalitet vid stickvägs- respektive beståndsgående förstagallring :

Nowadays the majority of the thinnings made in Swedish forests are done by machines, harvesters and forwarders. The most common model in thinning with a harvester is strip-road operated thinning and stand-operated thinning with one intermediate passage between the strip-roads. This study is a time study with some quality follow ups on a strip-road operated thinning model, a stand-operated thinning model with one intermediate passage between the strip-roads and a stand-operated thinning model with two intermediate passages between the strip-roads. The machines in the study were a small harvester (Forestline MPM C90) and a medium sized forwarder (Timberjack 1110). The study was made in Litsnäset outside the city of Östersund in Sweden and was made during the autumn 2007. In a lodgepole pine stand six study units (0,6 ha) were thinned with the three different models, two study units per model.

Pengar, press & partiledare : En studie om porträtteringen av makt i svenska tidsskrifter

We have studied how power is portrayed in Swedish journals by analyzing eight portraits of Swedish persons with economic or political power. We have studied how they and their power are described by the journalist in text and picture. We wanted to see which picture the journalist shows of people with power, what properties they are given by the journalist and how this picture is shown by the texts and the pictures. We have also looked if there are any differences between people with political power and people with economic power. We have under our studies noticed that the persons with power are described as very successful and special and this picture are shown in a very clear and unproblematic way..

Frekvens och spanningsskalning i en inbyggd mikroprocessor; for att mojliggora implementationen av schemalaggning med stod for dynamisk frekvens- och spanningsreglering for energihantering.

Minimizing power consumption is a critical part of many embedded design projects. Thechallenge is to limit the power consumption of the system and at the same time providesatisfactory service to the user. With regards to microprocessors, the main way of limiting powerconsumption during program execution is to adjust the frequency and the voltage at which theprocessor operates.To enable the implementation of real-time scheduling with support for dynamic voltage andfrequency scaling, an exhaustive study of the Freescale i.MX31 embedded microprocessor isperformed. Specifically, the power consumption relationship to all relevant frequency andvoltage settings is investigated. In addition, to enable frequency and voltage scaling in a real-timeenvironment, a complete timing analysis of proposed voltage and frequency scaling methods isperformed and their suitability for use in real-time systems is evaluated.To integrate voltage and frequency scaling capability into OSE RTOS, a software module hasbeen developed for this operating system.

Analys av det nordiska kraftnätets påverkan på det svenska elspotpriset.

During the last few years, there has been a lot of debate regarding the price ofelectricity on the Swedish market. According to a recent survey from Sifo, anon-bias governmental institute for consumer research and testing, the priceof electricity is what worries Swedish households the most. An investigationof the eciency of the Nordic power grids inuence on the Swedish spotprice is therefore both relevant and valuable. Three quarters of all electricityproduced in the Nordic region is traded at the Nord Pool Spot power market.This survey examines how much of the variation of the swedish spot pricecan be descried by the variation of the nordic system price and how much iscaused because of ineciencies in the power grid. Primarily, linear regressionwith adjustments for endogeneity and heteroskedasticity has been used in orderto analyze data obtained mainly from Nord Pool Spot and Vattenfall AB.The results show that the variation of the system price can account for all butabout 40% of the variation in the Swedish spot price.

Sjuksköterskans erfarenheter av att i palliativ vård arbeta enligt standardvårdplanen LCP

The purpose of this thesis is to identify power structures and instruments of power within the Jehovah?s witnesses and investigate how they affect the baptized youths baptized within the organization. The material consists of qualitative in-depth interviews and is analyzed with Foucault's theories of power. The results show that the participants have a very strict relationship to the rules of the congregation and also that they take great care in observing these rules carefully. It becomes evident that young members are exposed to disciplinary measures from the organization.

Undersökande journalistik : En analys av Uppdrag gransknings dokumentär om IKEA

This essay is about power in the classroom. It is about the power dimension of the student-teacher relationships that arise in that space. The overall aim has been to investigate which categories are fruitful in a power analysis of these relationships. My aim has therefore been to develop power categories and to use them to identify and to categorise cases of power interaction that take place between those particular actors in that particular setting.In order to gather material for my study I have both read literature that approaches the study of the student-teacher relationships from a power perspective and done a series of observations in a high school.My theoretical frame comprises a concept of power and a series of power categories. These categories include strength, authority, inducement, coercion, violence, resistance as well as to possess power, to have power, to exert power, the scope of power and the base of power.

Kvalitetssäkring vid en monteringslina : ett projekt på Swepart i Liatorp

För att Swepart Transmission AB ska fortsätta att hålla en hög standard på produkter som levereras till kunder, ska monteringslinan för Power Take-Off säkras. Budgeten som är avsatt till att kvalitetssäkra monteringslinan är 500 000 kr. Pick-to-Light och Pick-to-Voice är system som kan användas för att kvalitetssäkra monteringen av Power Take-Off. Systemen jämfördes med systemet med monteringskort som används i nuläget. Det mest lämpliga att införa har visat sig vara Pick-to-Light.I samband med införandet av detta system måste utredningar göras för vilka komponenter som behöver sensorer och vilka som kan säkras på andra sätt.

Scenarioanalys över Sveriges elproduktion år 2050 : Kan Sverige försörja sig med 100 % förnybar

The aim of this report was to investigate if Sweden can have 100 % renewable electricity production in the year 2050. The conclusion is that it is possible but under certain conditions. For instance wave power must be in commercial use. When wind power and solar power represent a large percentage of the electric production there will be a lack of electric power during the winter but during the summer there will be a surplus of electric power. Both the surplus and the lack of electric power need to be taken into account.

Introduktion av buskskikt i ungskogar

Young stands in urban forests often lack a shrub layer, though shrubs play an important structural and biological role in forests. All layers interact with one another to form a multilayered stand, in which shrubs have a vital role.In this diploma thesis, theoretical models for forest dynamics are compared with four reference stands to detect factors, and principals for introduction of shrubs in young stands. In these stands four different ways of introduction were found. In one trees and shrubs were planted together at the same time. Shrubs spontaneous spread under a canopy of mature forest, in another.

Religionsfrihet i Sverige : En studie om högstadielärare i religions tolkning av skolans icke-konfessionalitet

The purpose of this thesis is to identify power structures and instruments of power within the Jehovah?s witnesses and investigate how they affect the baptized youths baptized within the organization. The material consists of qualitative in-depth interviews and is analyzed with Foucault's theories of power. The results show that the participants have a very strict relationship to the rules of the congregation and also that they take great care in observing these rules carefully. It becomes evident that young members are exposed to disciplinary measures from the organization.

Digitala fotogrammetriska arbetsstationer för skoglig flygbildstolkning :

SCA Skog has taken the initiative to this Master?s thesis. Today SCA Skog has a great need to update their informtion on young forest stands across large areas. Traditional field inventory methods for updating stand databases are expensive and time consuming. However, the inventory could be made more efficient if stand boundaries and stand characteristics are derived from aerial photographs.

Avbrottsfri Kraft med användning av ultrakondensatorer

The supply of uninterruptible power can be applied to many areas wherecontinuous operation is highly prioritized.The application of uninterruptible power for motor operation is facilitatedusing a frequency converter. Direct current operated frequency converters canbe applied directly to the power reserve which removes the need for additionalpower-converting.Batteries have long constituted the power reserve but advancements inthe development of ultracapacitors have created a viable substitution. Ultra-capacitors have high energy storing capabilities and can be applied to highpower applications.Maxwell is a leading manufacturing company of ultracapacitors and pro-vide different modules with built-in solutions for voltage balancing. Unevenvoltages between series-connected capacitors is a phenomenon caused by vary-ing capacitance. A configuration containing Maxwell?s 56V module is createdand constitutes the power reserve in the simulations.The discharge simulation shows a significant current that could damagethe system.

FRAMTAGNING AV INSTALLATIONSKIT FÖR PROJEKTILINMÄTNINGSYSTEM

The report presents a thesis carried out on behalf of the company SAAB Training and Simulation which is situated in Huskvarna. The authors of this report are going to graduate as mechanical engineers focusing on product development and design, and this thesis should reflect the knowledge obtained during the education. The assignment, given from the company was to develop a concept of a stand that will constitute as a part of a mobile system for target practice. The reader get to follow throughout the project and can hopefully learn from the smart solutions and approaches that have arisen during the process.Today SAAB doesn?t have a mobile application in their portfolio that utilizes the benefits of their sensor measuring system, also called the LOMAH-bar.

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