Sökresultat:
1989 Uppsatser om Medium Voltage Network - Sida 3 av 133
EMC problematik och el-kvalitet i elkraftnät
The dissertation deals with an account of actual problem, which can arise within EMC and power quality. The cause of power interruption and what can be done to minimise the power interruption is discussed. It also includes a definition of planning levels and which factors one needs to have control over to carry out a possible planning strategy and how the local distributions net could be more secure. The electrical net could be secure but no system can be free from interruption.The dissertation examines two distribution transformers: GLA40T1 (Glansås) and T399 in Tranås Energy which don?t have regulators.
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..
Inställning av automatikermed spänningsreglerande verkani det sydsvenska 400-130 kV nätet
The voltage level in the power grid varies due to variations in load and production. Normally these variations are manageable, but they may be excessively large during a disturbance. If the voltage is too high it may damage the equipment in the grid and too low voltages may cause problems like voltage instability. The magnitude of the voltage variation depends on the short circuit power capacity of the point of interest.This problem may become lore prominent due to automatic voltage regulation that acts on shunt reactors and shunt capacitors. When the shunt reactor is connected or disconnected to the grid it may cause such large changes in the voltage that the shunt reactor starts hunting.
Spänningsstyrd underfrekvenslastfrånkoppling i elektriska kraftsystem
This report is a Master?s Thesis performed by Andreas Adolfsson and David Jacobsson atChalmers University of Technology. The purpose of this master?s thesis is to evaluate anew method for load-shedding, the voltage controlled underfrequency load-sheddingdeveloped by ABB. This report presents a comparison between conventionalunderfrequency load-shedding and this new method for load-shedding.
Implementation av Network Admission Control
This examination work is about implementation of Cisco Systems Network Admission Control (NAC) within a leading IT-company in region of Jönköping. NAC is a technique that is used for securing the internal network from the inside. NAC can verify that the client who connects to the network has the latest antivirus updates and latest operative system hotfixes. Clients who don?t meet the criteria can be placed in quarantine VLAN where they only have access to the update servers.
Framtidens elnät : Hur elbilar och solceller påverkar på det lokala elnätet
The purpose of the project is to determine the impact of solar cells and electrical vehicles on the future electricity grid and distribution network. Future electricity grids will be affected differently than it does today. Therefore, it is important to determine the impacts so that the current electricity distribution system can be developed and redesign to achieve the future demand. In Sweden, government has changed rules and laws in order to make it easier for private sector to invest in renewable energy sources. Our project focused on the impact of the solar cells and electric vehicles on the low voltage electricity distribution.
Nyhetsanvändning på Karlstads Universitet : -En studie av vilka nyhetsmedier som är mest använda och har högst förtroende bland studenterna på Karlstads Universitet
This essay deals with the subject of the use of news medium amongst the students inKarlstads University. The presentation of the problem is about illustrating the or thosemedium that is the most used amongst the students, and also which one, ore which onesof the news medium the students puts largest trust in. This subject was chosen with thepurpose to illuminate patterns and attitudes of and to news medium, to make it easierfor eventual research in the future to connect these patterns and attitudes with theparticipation in political elections. The subject in question is interesting because of thefact that the news medium is one of the largest sources of information for the citizensknowledge?s about the society, and the citizen?s attitude to the news medium mightpossibly have the ability to affect people?s commitment in politics.
Webb-tv ? en konkurrent eller ett komplement till linjär tv? : En studie av hur SVT och TV4 ser på sin webb-tv
The linear televison have dominated the supply of moving pictures, but this is about to change with the possibility to consume it via the Internet.I n this thesis we have studied how the two Swedish tv-network companies, SVT and TV4 are working with their web TV and if their online services have affected the linear TV. To limit the size of the study we chose two network companies that provide the most popular tv channels and web services in Sweden. To gather data from these two companies we conducted qualitative interviews with people at the networks. We came to the conclusion that SVT and TV4 doesn't find that their web TV services (called SVT Play and TV4 Play) are competing with the linear TV. They rather regard them as assets to broaden their services.
Framtidens elbilar utmanar nutidens elnät : Påverkan av ett ökat antal elbilar på ett halländskt elnät
The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years.
"Att bygga broar över murar" : en studie av ett kvinnligt ekumeniskt nätverk
The purpose of this master`s thesis is to examine how the contemporary changes in society display itself in the network Ecumenical Forum of European Christian Women EFECW and to increase the understanding of networks. My main questions are: What does the networks structure look like? What does the networks relationships look like? How is identity created in the network and what types of identities is created? The objectives are reached by using two methods, qualitative inquiries and document analysis. The inquiries were carried out to nine members in the network of different countries. The theoretical framework of the thesis is Manuel Castells theories of the network society, and the study is also placed in context by a presentation of previous research on the field.
The Co-Creative Network
The purpose of this thesis is to explore the co-creation process and how value is created based on a service orientation using a network perspective. The thesis is studied from a social-constructionist philosophy, using a qualitative approach of data collection and the theoretical framework includes network theories, theories of service-orientation and co-creation. We have conducted semi-structured interviews with a small firm and its network, which consists of a customer, a supplier and a partner. We found that Håkansson?s ARA framework combined with Ballantyne and Varey?s triangulation of value-creating activities help to acquire an understanding of the actors? bonds, the resources? ties and the activity links that exist in a network.
Framtidens driftcentral : En analys av den framtida driften av ett svenskt elna?t
Active work to increase the efficiency of energy use is taking place in Sweden and throughout all of Europe. Electricity is an important part in our society?s energy system which means that the electrical grid operators and associated therewith has a central role in this work. Monitoring and controlling the electrical grids are managed from the distribution system operator?s DC, dispatch center.The aim of this report is to examine how the operations in a typical DC on the Swedish electricity distribution network will look like in five to ten years.
Den första inblicken i regionala företagarföreningar : En fallstudie av Örebro Promotion
Many studies have been conducted of different types of business networks in recent years. Despite this, there is a lack of research concerning industry-transcending formal networks which are limited to a specific region. We have conducted a case study of Örebro Promotion, which is an industry-transcending network including over 500 members. Örebro is a medium-sized city in the middle of Sweden. The purpose with our study is to create an understanding of why enterprises choose to be a part of the network and what they feel is the gain of their membership.
En studie av sex ISA-system
On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.
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..