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5338 Uppsatser om Electrical Power Systems - Sida 25 av 356
Automatisk trimning av drivsystemreglering från MATLAB
This master thesis covers the development of an automatic tuning process for the existing speed controller for drive systems. The drive systems are resonant two-mass systems where a motor is used to drive a load connected by a shaft. The developed method relies heavily on system identification and the construction of a complete mechanical model of the process. With this approach, the common problem with poor load speed control that derives from measuring only the motor speed can be addressed and solved for a majority of such processes.The automatic tuning method has along with general test functions been implemented in a complete tool for automatic tuning, testing and performance evaluation and reporting for drive systems..
Strategi för utvecklande av reglerbudata
This Master Thesis discusses the development of bids for regulation power with consideration of change of discharge. The study was initiated by Vattenfall PD and is a limited part of a substantial development project at the same division. The background of the project is the new demands from SvK, which among other things includes more detailed regulation bids. As from the 1st of November 2008, the regulation bids are supposed to be calculated regarding each specific regulation object, something that is defined by SvK. These new demands changes Vattenfall?s conditions and will increase the need for detailed knowledge about available regulation power and costs for regulation.In this study a strategy for regulation bids was developed.
Webbens klassifikationssystem. En komparativ studie
This thesis deals with subject-based hierarchical search-services on the World Wide Web. The purpose is to investigate how systems of this kind facilitate information retrieval through subject-based information seeking. Its starting point is taken from the study of texts and qualitative analyses of search-services on the World Wide Web. Important aspects and features of the Internet and the World Wide Web are explained as well. Three systems are examined: Mölndals Stadsbiblioteks Länkkatalog, Svesök, and Alta Vista.
Urbana bomärken : människor och uttryck på drift
`When one does not have what one wants, one
must want what one has´: `I have had, you see,
to resort more and more to very small, almost
invisible pleasures, little extras....You´ve no idea
how great one becomes with these little details,
it´s incredible how one grows. ´
The aim of this master thesis is to find words and
expressions that can accompany city phenomenas
as well as the people wandering through the space
which is defiened as city. Through this tentative
search a new term was found namely Urban
Settler Marks. This term started a journey and an
attempt to theoretisize why people have a need for
various spaces to put their Urban Settlers Marks
onto. My focus was drawn to electrical boxes in
the urban environment because of their ambigious
nature.
Energianalys av tryckluftsystem : så kan Billerud Skärblacka AB spara energi på tryckluft
Compressed air is a low efficiency media, and is thus very expensive to produce. This thesis work began by mind mapping how to create savings on the compressed air system at Billerud Skärblacka AB. Certain issues have been chosen for further studies.In order to identify the consumption of compressed air at PM 8 and 9, several measurements were made. At PM 8 there were not found any pressure drop, only large pressure variations for short periods of time. The causes of these pressure variations were not established.
Distribuerade fastighetsautomationssystem : - En implementation av kommunikationsprotokollet BACnet
Building Automation Systems in commercial buildings are often designed and installed by different contractors, using equipment and components from different manufacturers. The lack of an accepted communication standard has resulted in a few different standards. Many manufacturers of building automation systems only support one, a few or none of these standards, while developing proprietary system solutions. Regin, who develop such equipment, are planning to adopt an open communication protocol specially designed for building automation - BACnet. As a step in that direction this thesis was announced with the purpose to investigate the possibility to implement BACnet in one of their products and to gain more knowledge of the BACnet protocol.
Damned if you do, damned if you don´t
The purpose of this paper is to explore the social worker?s perspective on working for the government as a professional in care of children, in relation to the family's right to self determination. The essay's empirical material is gathered from qualitative, semi-structured interviews with social workers who work with children and youth in communities and districts in Skåne and Stockholm City, Sweden. The analysis was conducted in line with theories of social constructivism. The results and analysis show that the interviewed social workers did not believe that the state has too much power over the citizen.
XML som informationsbärare för EDI
Information handling has been a key issue for different companies for a long time. Electronic Data Interchange (EDI) is used to transfer different business documents from one company to another. This is done in such way that the information itself is separated from how this information is stored and handled in the companies internal systems. As different companies have different systems there is a need for a standardised format for this exchange. There is a big difference between EDI-systems based on what kind of EDI-standard is used.
Varför dela makten? En studie av consociationalism och Democratic Unionist Partys beslut att delta i regering på Nordirland.
On the 8th of May 2007 a local power-sharing goverment consisting of Sinn Fein and the Democratic Unionist Party (DUP) was formed in Northern Ireland. The aim of this dissertation is to explore why the DUP, who in the past have opposed all forms of power-sharing decided to form a goverment and take active part in a power-sharing agreement. The study is based on a consociational theoretical framework developed by Arend Lijphart and further developed in a Northern Irish context by John McGarry and Brendan O'Leary. Using this theory the study seeks to understand the broad conditions surrounding the DUP's power-sharing. After a description of consociational theory and the road leading up to the Belfast Agreement,three possible explanations for power-sharing, based onconsociational theory are discussed.
Mobil kommunikation och högre tillgänglighet vid längre elavbrott : Exemplet stormen Dagmar och 4G-kommunikation inom smarta elnät
To be able to secure a safe and reliable power supply is becoming increasingly important since society depends on services and functions that need continuous power supply. The delivery rate in Swedish power supply is 99.98 % which insists on a high availability. During the past decade several storms has passed Sweden which resulted in large amount of tree felling leading to extended power outages. During these storms many socially critical activities, such as electric utility company Fortum, experienced disruption in mobile communication which affected the crisis management. This paper has investigated Swedish mobile operators? crisis management at Hi3G, Tele2 and TeliaSonera with a case study of the storm Dagmar that hit Sweden during December in 2011.
I Europas hjärta; Det brittiska ordförandeskapet under förhandlingarna om EU:s långtidsbudget 2007-2013
This thesis analyses the 2005 UK presidency of the Council, and more particularly the negotiations on the future financing of the European Union. The purpose of the study is to discuss whether the holding of the presidency implies political influence for the member state. To analyse the power of the country holding the chair the thesis focuses on the presidency functions of brokering and leadership. The theory suggests that the influence of the presidency is derived from informational and procedural power resources, as well as some leadership resources, such as coercion and reward. A case study was used to analyse whether these power resources were used by the British presidency.
Deriving ECA-rules from timed-automata specifications.
Real-time systems are required to answer to external stimuli within a specified time-period. For this to be possible, the systems behaviour must be predictable. The use of active databases in real-time systems introduces unpredictability in the system, e.g. due to their use of active rules. The behaviour in active databases is usually specified in ECA-rules.
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.
Power Shift and Retailer Value in the Swedish FMCG Industry
Background: The recent years in the Swedish Fast Moving Consumer Goods industry have been characterized by a palpable shift in power balance, favouring the retailers. Since the shift in power balance has strengthened the negotiation position of the retailers, the suppliers now have to, to a greater extent than before, accommodate to the retailers? goals, whether they be financial or strategic. Purpose: The aim of this study was to investigate how this recent power shift has affected the relationships of suppliers and retailers. This development has resulted in the rather new and unexplored area of retailer value, which this study further aimed to explore.
Hantering av informationssystem
Lund who has over 90 systems in 12 departments and now wants to streamline the management of these IT systems. Governance of IT systems is something that Lund would treat as it carried a large amount of changes in their practices, where the control is something missed in trying to standardize their systems. What's missing for Lund Municipality is routine to fall back on in order to streamline the management when they get into these complex situations.Given that Lund treat so many systems make it so that the situation quickly becomes very complex due of the organization's structure. The municipality is divided into twelve departments that have their own goals, it is an organization that is organized, which makes creating standards become complicated when all departments have different needs. Our study was based on a framework that deals with complex environments that lack a clear definition.An analysis was conducted where we started from the theory associated with the interviews conducted in which we aimed to understand their decision and understand the processes that affect system development.