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3425 Uppsatser om Power network - Sida 1 av 229

Sårbarhetsanalys av ett infrastrukturnätverk - Användning av nätverksteorier för sårbarhetsanalys av komplexa nätverk

The aim of this report is to examine the possibilities to use network theories to perform vulnerability analysis on complex networks. The scoop of this work is also to improve the possibilities to chart, analyze and present the vulnerability in a power grid. In this report it has been, using power outage statistics, possible to verify, that network theories can be used to evaluate the vulnerability of an infrastructure network. However further studies to establish values on how vulnerable a network is are needed..

Överföring av och beräkning med timmätta värden ? från MT2000 till Xpower

New technology makes it possible to remotely measure all consumers in a Power network onan hourly basis and store the values in a database.This thesis work describes the conversion process between automatic meter reading systemMActor and calculation software Xpower.Then the possible differences between calculations of Power networks using load curves incombination with a yearly estimate of consumption and calculations using hourly measuredvalues is examined.The result of the comparison shows that, for the Power network under inspection, nosignificant difference could be noticed. This does not mean that calculations using hourlymeasured values would be unnecessary. I believe that in a near future calculations using hourmeasurements will be the primary choice for many power companies to whom technology isavailable.Also some basic calculations of fundamental Power network parameters, such as power factorand loses, are presented using hourly measured distribution transformers in combinations withits hourly measured loads.The report is written in Swedish.

Minivindkraftverks inverkan på lågspänningsnät

Micro-power wind energy convertors have recently increased in popularity. The reasons for this are among other things the increasing cost of electric energy and enviromental concern.In this thesis the connection of these micro-power wind energy convertors to the utility network is discussed. Electric standards for the connection of small production units is presented. Finally some calculations and measurements of electric quality are also presented. The utility network used in the calculations is part of Halmstad Energi och Miljö network..

Kartläggning av nätförlusternas storlek inom Mälarenergis elnät

Energy losses are an essential part of a power grid company?s costs. From anenvironmental and economic perspective, it is important to reduce these costs. Toknow where efforts should be deployed, it is important to have good knowledge ofwhere in the network losses are situated. When creating network tariffs, there is alsonecessary to have a correct distribution such that the network customers that use acertain part of the network, only pays for the network losses in this area.

Beredning av lokalnät i landsbygd

In this thesis a rural network in Norrbotten, Sweden, has been to designed and planned with the purpose of improving distribution reliability by exchanging existing overhead lines with underground cables. General network design considerations are discussed as well as the ones for the specific low voltage grid. During the design phase the maximum power of domestic consumers has been estimated using Velander?s method. Currents, voltage drop and impedance of the network have been calculated and fuse operation and selectivity has been considered.

Nätverk och makt - En fråga om makt och relation mellan politiker och tjänstemän

I have studied how network in a broad sense can affect decision-making. The primary purpose is to see if the political initiative somewhere disappears when it comes to understand the relations between power, actors and politics. The study discuss in a theoretical area that concerns the reliability in neoinstitutionalism to use as an analytical instrument. Some criticism is given to the theoretical standpoint in the sense that there is no power perspective included in the theory. I include a discussion about a concept of power, which I include to the theory.

Värdeskapande i nätverk

The purpose of this thesis is to examine value creation in networks. Based on a case study of Livebookings Network, an online booking service. This thesis has an explorative nature. As a theoretical framework we use theories on value and network dynamics. By combining these theories we develop an operationalized framework that we use to analyze our empirical findings.

Tidssynkroniserade mätningar i vattenkraftstationer

Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.

Small-worlds och rich-clubs bland bloggar : En nätverksanalys av den svenska bloggosfären under FRA-debatten 2008

Purpose/Aim: To find power structures within the blog network.Material/Method: Using keywords to find all available blog posts about the National Defence Radio Establishment from the blog search engine Twingly, and thereafter using the same blog search engine to find inlinks from other blogs, to those posts. The data is set into the context of the small-world networks models of Duncan J. Watts and rich-club models of Sergi Valverde och Ricard V. Sole.Main results: 5183 unique blogs have written about the subject in 22779 blog posts to which 28128 inlinks from other blogposts are made. Just over one fifth of the blogs are linkted to each other in one big network, where the remaining blogs stand without any ingoing or outgoing links.

BSR Prestandaverktyg / BSR Performance tool : Prestandamätning via diagnosuttag över CAN / Performance measure via diagnostic socket over CAN

 This abstract describes the bachelor degree thesis in computer technology at Växjö University. The company BSR in Växjö has requested an application that can measure a cars performance, with attributes like acceleration times and engine power estimation. The communication between car and computer is via the USB port on the computer and the OBD-II socket on the car with the network protocol CAN, controller area network. Cars from VAG have been the primary focus group and the application has been tested on a Volkswagen Passat CC from 2009. The system is developed in the programming language C# in the environment Visual Studio with the framework .NET.

Från soptipp till naturreservat : En studie av makt i Lövsta-Kyrkhamn-Riddersvik genom actor-network theory

This paper investigates, through an actor-network theory perspective, how the recreation area Lo?vsta-Kyrkhamn-Riddersvik northwest of Stockholm has developed from being a dumping site into becoming a nature reserve. This investigation also tries to describe and explain which values that have been promoted in the area by the local voluntary associations and companies. Lo?vsta-Kyrkhamn-Riddersvik has been inhabited for more than 3000 years, originally with farming as the most important business.

Självförsörjande elgenerering : Kan Orust bli självförsörjande på förnybar el?

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.

Konstruktion av en autonom vindstation

Construction of an autonomous wind station was a project with the goal of creating a product that could collect wind data from a sensor and then transfer this data to a server wirelessly over the GSM network. The device would be powered by batteries and solar cells and function fully without requiring external power supply. This required that a small computer was constructed and programmed to store and send data at predetermined cycle times and programming of a server that received the sent data. The project also required optimization of power consumption and dimensioning of solar cells and batteries based on this. The construction of this station demanded research both for the selection of hardware and programming software. The computer was based on a microcontroller and a GSM module that sent the data over the 2G network.

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.

Urval och risk i informell finansiering av entreprenörsprojekt : En fallstudie av Firm Factory Network

This thesis discusses various approaches that venture capitalists have when evaluating investment prospects. The thesis is a case study of the business angel network Firm Factory Network. The empirical material is based on an extensive interview with Firm Factory CEO Daniel Kaplan. Our conclusion is that Firm Factory Network uses both informal and formal methods when they evaluate interesting prospects..

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