Sökresultat:
438 Uppsatser om Numerical grid - Sida 10 av 30
Magnetfält alstrade kring nätstationer i samband med lokaldistribution av elkraft : Magnetic fields generated by electrical substations during distribution of electric power
Abstract: This report covers primarily the work of documenting electromagnetic fields generated by one of the later parts in the electrical power distribution chain: The electrical substation, wherein 10 kV is transformed to 400 V for use by private consumers. Thus it is one of the most widespread and frequently occurring parts in the Swedish power grid and of particular interest, as electrical substations are found everywhere in populated areas, often in close vicinity to people and animals.The report deals with a number of formulated questions and/or hypothesis? stated at the onset of the work undertaken, theory that is relevant for the topics the report covers, the details of the field work undertaken and the following analysis of the readings, which in term provide answers for the questions stated in the beginning. It also covers what is the currently known short term and long term risks associated with electromagnetic fields in the power frequent spectrum and of varying intensity in the vicinity of humans.The analysis also provides recommendations and identifies several points to carefully consider when planning for new installations or replacements of some parts of existing installations.For enhanced reading comprehension there is, aside from sections with pictures and attached explanatory texts and templates, several graphs, one-line diagram and maps of the power grid among the appendixes to the rapport..
Pilotinstallation av fast och fjärravläst nätstationsmätning : Identifiering av för- och nackdelar med nätstationsmätning, Mälarenergi Elnät AB
Today?s electrical grid companies understand that better knowledge of and information about their grid can help realize a smart grid network. One way to gain better knowledge and information about the low voltage network is to install measuring equipment on the substation transformer´s secondary low voltage side that measures the low voltage network losses for that specific substation. By doing so, grid companies can, due to the calculation of the low voltage network losses, identify and address issues such as illegal power dissipation, unmeasured power outtakes, and unsatisfied technical documentation for the substations low voltage network.During 2012, Mälarenergi Elnät AB had a total electrical network loss (both medium and low voltage network losses included) of three to four percent of their total distributed electrical volume. Converting this energy volume into a monetary figure this accounts for a loss of around 30 million Swedish crowns.
Hur påverkar en ökad andel solceller Umeå Energis elnät? : ? En utredning med fokus på spänningsvariationer och osymmetri inom landsbygds- och tätortsnät vid en- och trefasanslutning av solcellsanläggningar
A good power quality can be an important prerequisite to achieve a sustainable society. Scandinavia's electrical system is in many respects superior, and Sweden has a fossil free electricity generation at 97 % and a reliability of electricity distribution at 99.98 %. Meanwhile, the EU has an ambition to expand the electricity market in order to achieve a joint trading business across Europe. This cross-border market will result in a large proportion of fossil energy sources integrated into our electrical system, which also leads to an increased need for renewable electricity production in Sweden. One part of this development is to increase the share of renewable micro generation that is locally or regionally connected to the power grid.
Utvärdering av olika metoder för framställning av höjdkurvor från laserskannade höjddata
Lantmäteriet (the Swedish mapping, cadastral and land registration authority) has been laser scanning Sweden since 2009. From the laser scanned data a digital elevation model (DEM) in grid format, with a resolution of 2 m, is produced. This DEM is called GSD-Höjddata, grid 2+ and from its data and the laser point cloud itself (in the form of a las-file) contour lines can be extracted. Lantmäteriet has not yet done this, but plans to update the contour lines in their cartographic products exist. If this is to be done in a satisfactory way an evaluation of different methods for it is needed.
Höjdmodellering med laserdata : Studie av Kärsön, Ekerö med fokus på upplösning, datalagring samt programvara
The New National Elevation Model (NNH) is a new high-resolution digital elevation model (DEM) of Sweden from airborne laser scanning. It creates many new opportunities, particularly in the area of flood mapping. NNH is provided by Lantmäteriet in two formats, both in raw LIDAR (Light Detection and Ranging) data and in grid format with two meter resolution. These alternatives have advantages and disadvantages and the aim of this thesis research is to identify these. One of the focuses of the study is data storage and thus data structure analysis, resolution and storage facilities. The research questions are:Why and in what context the different NNH-products from the National Land Survey are used (DEM 2+ or point cloud)?What constraints and opportunities are created by the different options, mainly in terms of different software, resolution, and data storage?The study area is Kärsön in Ekerö municipality located in Stockholms län and has an approximate area of 25 square kilometers. The study is divided into two parts. The first objective is to identify the consequences of using different software to create DEM from pointcloud compared to the DEM2+ model. Height models with a two meter resolution are created in FME and ArcGIS. The models are then compared with the grid from Lantmäteriet, created in TerraScan. The second objective is to examine the impact of the change in resolution, both the storage aspect and both the accuracy aspect. Inverse Distance Weighted (IDW) is an interpolation method which in previous studies proved to have the best results on high resolution LIDAR data. This model was tested and compared with a model from FMEs built-in function and the model from Lantmäteriet wich are based on triangulation (also proved a good method in previous studies). The grid created in TerraScan has good properties such as accuracy.
Design av en webbaserad person- och släktskapsdatabas
Denna examensrapport redogör för en utvecklingsprocess av en webbasserad släktforskningsapplikation, där resultat från släktforskning kan delas av flera aktiva släktforskare. Genom att grundligt undersöka olika datamodeller och befintliga applikationer försöker arbetet säkerställa grunden till en unktionell webbapplikation. Arbetet ledde till en betaversion med begränsad funktionalitet som skall vidareutvecklas i framtiden till ett GNU/GPL projekt med öppen källkod för gratis användning och nerladdning. Målet med arbetet uppfylldes i stora drag, det frångicks dock lite på grund av tidsbrist som uppstod i samband med prototypprogrammeringen..
Analys och organisering av ö-drift för en samförbränningsstation vid Åmotsfors bruk
Åmotfors Bruk AB (ÅBAB) has today an inefficient production of steam for the
manufacturing of paper. Unpredictable energy prices and modernisation of the current
equipment has been the underlying factors to invest in a thermal power plant, mainly
driven by garbage. This facility will not only use the steam for paper production, it will
also generate electricity through a steam turbine. Today, when a fault on the supplying
line occurs which leads to disconnection of the external grid, all the support of electricity
to Åmotfors Bruk (ÅB) will disappear. This will lead to major interruptions in the paper
production, which will cause severe economical losses.
Förändringar av marknadsdesign och deras påverkan på balanshållningen i det svenska kraftsystemet : En kartläggning och analys av de balansansvarigas arbetsgång
A future expansion of wind power in the Nordic power system makes the balancing for the transmission system operator Svenska Kraftnät (SvK) more complicated. Up to the hour of delivery the balance responsible parties? (BRP) makes prognoses and plans, for consumption and production, to help maintain the balance in the electrical grid. How well this is accomplished is affected by the setup of the market design. Therefore SvK has proposed the following possible changes in market design: Increase the imbalance costsIntensify the regulation of imbalancesIncrease the temporal resolution on the different marketsPresent the prices for balancing power in real-timeModify the balancing market to simplify auction of consumption bidsA mapping over the BRPs? processes within planning and trading on the day-ahead, intra-day, and the balancing market has been performed in this thesis.
Välfärdseffekten av en konkurrensutsatt tågmarknad
The aim of this paper is to describe how to measure welfare effect of the deregulation and increased competition of the public transport by railway in Sweden. The paper also includes a numerical example of how to measure the welfare effect. In our study we use public data from SJ regaring quantity and ticket prices for the period 1996 - 2005. We have used equivalent variation, EV, as the method to measure the welfare effect. We demonstrate how to derive the equation to calculate EV by starting with a Marschallian demand function.
Matematiska färdigheter hos elever med lässvårigheter i årskurs 4
Reading difficulties is the most common learning difficulty in the western world and it is common that people with reading disabilities also exhibit arithmetic difficulties. Different theories about the cause of the relationship exists, one theory describes the importance of good phonological ability in reading as well as in arithmetic, while another theory describes the importance of a reliable number system and that only a subgroup of students with reading disabilities also have difficulties with arithmetic. The purpose of this study is to investigate how students with reading difficulties (RD), without any known mathematical difficulties, perform on mathematical tasks relative to a control group. The study was theoretically grounded on the Triple code model (Dehaene, 1992), which is a model for numerical information processing that describes how various numerical and arithmetic tasks are processed through three distinct representation systems in the brain, a verbal and a visual representation system and a quantity system. Reading skills, phonological skills, arithmetic skills and number processing skills were examined in 61 students through a variety of tests.
Konvertering från luft till vätskekylning av elektronik
A Swedish electronics company wants to make the cooling of one of their electronic components more efficient. They propose that a retrofit liquid cooler is the way to achieve this goal. The current air cooling has high energy cost due to the high amount of power needed to power fans and heat exchangers. Using high volumes of air for cooling also leads to noise pollution. The conversion from air to liquid cooling would possibly make the operation of the electronics more cost efficient and less noisy.The purpose of this project is to theoretically evaluate different concepts of drawing the heat generated by the electronic component in to a fluid, using numerical calculations in Matlab and FEM simulations in ANSYS.
Isaac Newton och den matematiska naturfilosofin
In several scientific and technical educations today we meet mathematical studies in differential- and integral calculus. The classic mechanics is a foundation for the physics and it has made it possible for today's technical developments that we in our everyday life meet and make use of. The intention for this essay is to give a picture of the person behind this discoveries that changed the science and the world. Besides the purpose to bring the reader on a journey through Isaac Newton's life the main intention is to give an understanding of the way he discovered the binomial theorem, the differential- and integral calculus, the numerical methods Newton-Raphson's and Newton's interpolation-polynomial, Newtons identities and his classification of third-degree curves and elliptic curves. A derivation of Kepler's first law is also included..
BIM vid installationsprojektering
Planet rendering plays an important role in universe visualization and geographic visualization. The recent tools and methods allow better data acquisition, usually with very high resolution. However in computer graphics, there is always the limitation on the resolution of geometry and texture due to numerical imprecision. Not many applications can handle high resolution data effectively.This thesis introduces, Implicit Surface Scene, a level of detail scene management inspired by dynamic coordinate system and SCALEGRAPH? which change over time depending on the current camera position relative to the planet surface.
På vilket sätt förbereder sig kreditinstituten inför avskaffandet av revisionsplikten?
Sedan 2003 har Bokföringsnämnden (BFN) arbetat med ett projekt innehållande redovisningsförenklingar. 11 juni 2008 beslutade BFN att ge ut allmänna råd och vägledning för mindre företag, K2. (BFNAR 2008:1) De företag som innefattas i K2 är en stor grupp med 96 % av alla svenska aktiebolag. Kritik som BFN har fått är att enheten jobbar under knappa resurser och att de största företagen inom K2 kommer att ha svårt att redovisa med en rättvisande bild.Hur är kunskapen om och behovet av BFNAR 2008:1 för det övre segmentet inom kategorin K2 i dagsläget?Syftet med denna uppsats är att undersöka behovet hos företag i det övre segmentet inom kategorin K2 samt att se hur kunskapen och attityden är till BFNAR 2008:1.
K2 : Finns det ett behov hos företagen i dagsläget?
Sedan 2003 har Bokföringsnämnden (BFN) arbetat med ett projekt innehållande redovisningsförenklingar. 11 juni 2008 beslutade BFN att ge ut allmänna råd och vägledning för mindre företag, K2. (BFNAR 2008:1) De företag som innefattas i K2 är en stor grupp med 96 % av alla svenska aktiebolag. Kritik som BFN har fått är att enheten jobbar under knappa resurser och att de största företagen inom K2 kommer att ha svårt att redovisa med en rättvisande bild.Hur är kunskapen om och behovet av BFNAR 2008:1 för det övre segmentet inom kategorin K2 i dagsläget?Syftet med denna uppsats är att undersöka behovet hos företag i det övre segmentet inom kategorin K2 samt att se hur kunskapen och attityden är till BFNAR 2008:1.