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3983 Uppsatser om Electrical distribution systems - Sida 2 av 266
Analys av fördelningssystem för bostadshus
The purpose of this project is to analyze earthing systems for houses. By practical measurements and theoretical analyzes consequences of possible faults, that can occur within the facility and in the low-voltage distribution network, is illustrated. The reason for this project is that nowadays one has to arrange with a main equipotential bonding system for buildings. Apart from that, if necessary, bathrooms must be provided with a supplementary equipotential bonding system.The practical measurements verify that potential differences in facilities may be due to voltage drops in the PEN conductor between the origin of the electrical installation and the power transformer.Based on the theoretical analyzes of possible faults, it is considered that the requirement for supplementary equipotential bonding systems for bathrooms in most cases can be questioned, when basic insulation, fault protection, residual current devise and main equipotential bonding system already provides an adequate level of protection.A PEN conductor loss may result in a situation where metallic parts attached to the equipotential bonding system starts working as earth electrodes. Equipotential bonding system may also increase the incidence of stray currents. If TN-C-S systems is provided with a local connection to earth a redundant system against PEN conductor loss is obtained.
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.
Smart Control : En reaktion på EU:s ekodesignkrav
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.
Vidareutveckling av PV/T-receiver för koncentrerat solljus
The rising demand for electricity and heat raises a big challange for the society and engineers. Many products have been introduced to the market to supply more energy to the energy systems. Absolicon AB is a Swedish company that develops and markets a combined heat and power generating product. The product, Absolicon X10, uses a parabolic trough to concentrate the radiation of the sun onto a receiver. The receiveris equipped with mono crystalline solar cells and is cooled by a circulating liquid media.
Distributionsekonomisk optimering av dagligvaruhandelns lokalisering : förstudie till ett forskningsprojekt
The structure and performance of grocery distribution in Sweden has changed profoundly since the second world war. Increasing access and usage of the private car, in combination with an accommodating town planning has enhanced the exploitation of scale economies within distribution firms. There is, however, some ambiguity concerning the overall efficiency of the distribution system when the costs associated with travelling and purchasing performed by households are treated as an integrated part of the total distribution cost function. The purpose of this master thesis is to develop the foundation of a spatial optimisation model, which defines the most efficient distribution system. The underlying idea is that the optimal localisation and size of grocery stores is a function of economies of scale within the firms weighed against distributions costs within the households, such as transportation costs.
Utveckling av OBD-II-gränssnitt för fjärrdiagnostik av fordon
This Master Thesis documents the development of an On Board Diagnosis (OBD-II) interface for remote diagnosis of vehicles. The Master Thesis is part of a project at the company Wayfinder Systems in Lund. The purpose of this thesis was to design a scantool that communicates with a vehicle through its OBD-II port using relevant standards. In order to make the OBD-II interface development easier, a car simulator was first built. Both the car simulator and the OBD-II interface were implemented using a linux computer running a C-program with serial communication with an external electrical interface.
Transportsfordon för rullstolsburna
A vehicle that carries a person sitting in a wheelchair has been rebuilt. The original vehicle was provided with a petrol engine, hydrostatic drive and a mechanical steering rod, making it noisy and hard to maneuver. The purpose with this project was to convert the vehicle to make it more environmental and easier to drive.A new design has been proposed where an electrical drive has replaced the noisy combustion engine and an electrical motor with joystick control has replaced the manual steering.The project was divided into two parts. One mechanical part where the construction of the drive and steering were to be decided. The other part involved programming the microprocessor and implementation of all the necessary electrical for the control system of the vehicle.
How streaming media can be used in commercial mass
distribution
Mass distribution with techniques as multicast and peer-to-peer are becoming increasingly important in the Internet. Today the distribution of sound and video over Internet, so called streaming media, is static due to the unicast method. This results in a linear increase of distribution costs and therefore no conditions for commercial scalability. This thesis describes why multicast may be the only scalable alternative for commercial mass distribution of streaming media over Internet. Mass distribution through peer-to-peer technology promises a lot but is fronting a couple of great challenges, for example asymmetric bandwidth, locality and legalization.
Val av överlastskydd för elektriska ventilmanöverdon på kärnkraftverket i Forsmark
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..
Tillbaka till framtiden - om svensk filmdistribution i den digitala eran
Why is the e-revolution of the Swedish film distribution lingering? In attempting to answer that question, this qualitative study depicts the distribution market of Swedish film and its actors. Thirteen interviews with representatives of the industry have been conducted in search of an understanding of the current situation. Two important conclusions are made. One is that the strong interdependency between the actors of film distribution is inhibiting the acting space of those who seek change.
Digital videoväxel
This thesis discusses the possibilities to distribute digital video in a military vehicle. Today, an analogue system is used, which has a maximum capacity of eighteen video sources and the same number of monitors. The purpose of this thesis is to increase the systems capabilities regarding secure distribution and additional functions. Both software and hardware tests are made to investigate the features of the digital video standard MPEG-2. Both the coding delay and the image quality are of great interest.
Analys av mellanspänningsnätet i centrala delar av Västerås stad
The dependency of continuous electricity supply is high in the Swedish society today, at the same time no one is willing to pay for a too costly or over dimensioned power distribution system. The owners of the distribution systems are the ones responsible for this balance act of maintaining a high quality of electricity delivery to customers at a reasonable cost.In this master thesis a limited part of the primary distribution system (10 kV), owned by Mälarenergi Elnät AB and located in the city centre of Västerås, was chosen for a deeper analysis of its reliability. Its ability to handle outages of system components (N-1 and N-2 contingency analysis) was investigated to find out potential weak spots and parts of the grid that showed signs of being overdimensioned.The results of the performed simulations showed that in 74 % of the studied N-1 contingencies cases, consisting of outages of a bus bar in a distribution substation, the system could handle this without causing outages in other parts of the grid. For the N-2 contingencies 61 % passed the test. It was also found that one of the two included high voltage substations could alone supply the investigated part of the grid.
Luft/luftvärmepump : - Med möjlighet till återvinning
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.
Spillvärmeåtervinning ur kylvattensystemet ismältverket på Sapa Profiler AB i Sjunnen
The smelting process at Sapa Profiler AB in Sjunnen generates large quantities of waste heat which is absorbed by the cooling water when the aluminum is cooled down. This paper is the result of a Master?s Degree Project aiming to present the conditions for recycling the waste heat. The cooling water absorbs the heat from the aluminum at an average rate of 600 kW and the paper shows that it can be used to replace electrical power consumption for heating the production plant?s facilities.
Modeller för studier av ursprungsmärkt el
The EU has decided that it should be possible for consumers to get information about the origin of the electricity they buy. Therefore, there is a need to examine different systems for electricity disclosure. In this thesis two ways of disclosure have been studied:? Certificate system. A certificate system involves two parallel markets, one for trading electrical energy and one for trading certificates of origin.? Separated Markets.