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11215 Uppsatser om Stand-alone power system - Sida 18 av 748
SPICA - ARISTO JÄMFÖRELSE studie av analysprogram med avseende på spånningskollaps i elektriska kraftsystem
Safe operation of a large synchronous power system as Nordel is not an easy task.There are several aspects to take into consideration. This thesis focuses on the problems due to voltage collapses in a transmission system.The ability to foresee an upcoming collapse is vital to maintain stable operation of the grid. The grid operator at Svenska Kraftnät (SvK) uses the computer program SPICA to predict the maximum transfer limit at specified transfer sections. SPICA uses actual states from the grid to predict the transfer limitation, and a quarter later a renewed estimate is produced and so on. This means that the operator can se his transfer limits vary every fifteen minutes.Our task in this project is to validate the accuracy of the limitations obtained by SPICA.
KORTSIKTIG PRODUKTIONSPLANERING I MINDRE FJÄRRVÄRMESYSTEM : En studie vid Strängnäs Energi AB
District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.
Utvärdering av svensk vindkraft : Skillnaden mellan skogs- och traditionella placeringar
During the last years commercial Wind Power Turbines (WPT) has become larger regardingto the generator sizes and hub heights. Available hub heights around 100 meters is nowcommon, which has led to profitability for WPT located in forests where there normally are tolow wind speeds. The current knowledgement regarding turbulence and the variation in thewind profile for the outcome of the power production for the WPT in forests is limited.In this Master of Science thesis an investigation concerning forest located wind power plantshas been made. The purpose has been to investigate if plants located in forest perform lesscompared to wind power turbines located at more common locations.The analyses are based on statically material for determining the availability,production/generator size, production/hub height, production/swept area and how thetopography affect the production results.The analyses show that the variation in production result for WPT located in forest comparedto turbines located at other locations is small. The availability is high and the productionresults are good..
En liten bit musikdramatik : - en studie i fenomenet scenisk gestaltningsprocess - hieroglyf No 1: The Fall
Prisons are for many an unknown world, and few know about the prison culture which includes unwritten rules, power structures, interactions and relationships between inmates and correctional employees.While many think that Swedish prisons are too comfortable,inmates are facing extreme stress due to surveillance and detention, by depriving inmates their possibility to shape their own lives. When the inmates is deprived of control over their own life?s the penal system have great power to shape and to influence the inmates.The purpose of this paper is to investigate prisoners' experiences of treatment and exercise of power in prisons. Starting point is to examine what are the kinds of relationships between prison officers and inmates from a power perspective, if there is any difference between the closed and open prisons and how the inmates affected by the structures that exist.Based on my overall purpose, and with my informant´s stories which revealed a number of similar points, four main headings were developed; Mass media and society´s view, and unknown world, interaction between inmates and prison officers and consequences.Prison officers with the role as a contact persons as well and other staff which work close to the inmates play a significant role by supporting through motivational interviewing and can help the inmates to gain insight about their life situation and actions. My informant?s underlined that a good contact person can either help or discourage.Inmates who contributed with their experiences express that there is a big difference between open-and closed prisons.
Vem får höras? : En undersökning av lokalpress kring makt och kön i fyra Landsortstidningar
2 (45)AbstractAuthors: Gunnel Forssell Ehrlich & Alexandra WinbergTitle: Gender in local press ? a quantitative study of four local newspapers Level: BA Thesis in Media and Communication StudiesLocation: Linnaeus UniversityLanguage: SwedishNumber of pages: 50The report shows a quantitative study of balance in gender and position of power in the local press. The study aimed to shed light on the distribution of space in the newspaper between men and women, those within power and those without in Swedish local press. The study was conducted with four newspapers, during a month of time with local editorial news material. In our study, we have assumed Lippmann?s and Strömbäck?s theories of pseudo-reality and distribution of gender and position of power in Sahlstrand and Jarlbro.
Förutsättningar att utforma stationsbatterier i vattenkraftverk med Li-jonteknik
In hydropower plants it is necessary to always have local power supply. Therefore, the plants are equipped with batteries as stationary back up power. Vattenfall Vattenkraft is using lead acid batteries but has been investigating alternatives to replace them. The aim of this study is to investigate the potential of using Li-ion technology as back up power.The study showed that Li-ion batteries have many qualities. The Li-ion technology will decrease the space and maintenance demand.
Lyckliga i alla sina dagar? : Makt, kön och heterosexualitet i tre Disneyfilmer
The purpose of this thesis was to examine the ways in which the constructions of heterosexuality and gender in three Disney movies about princesses affect the power relations between men and women in the movies, and how discourses on gender and heterosexuality have changed over time. Research questions were:How do characters in the movies talk about gender and heterosexuality?How does the interplay between gender and heterosexuality affect the power relations between men and women in the movies?What are the likenesses and differences between movies from different time periods?Discourses were mapped out using a model based on Ernesto Laclau and Chantal Mouffe?s political theories. These discourses were then analyzed with a theoretical framework consisting of Yvonne Hirdman?s concept of gender system and gender contracts, Judith Butler?s view on the heterosexual matrix and an understanding of power relations based on Michel Foucault.
Energikartläggning hos RostiGP i Gislaved
In today?s modern age, energy consumption has become a major issue, both from an environmental viewpoint and cost perspective. Because of a rapid technologic change and increased costs of production of electricity, the demand to develop effective methods for energy efficiency industries have grown.The electricity-intensive industries, such as plastic industry, the demand to reduce energy consumption has grown significantly over the past 10 years, which have led to the development of different methods to determine and locate energy-consuming parts in the industry. This also means being able to prioritize and organize activities in the industry.In this study the measurements of voltage, current, power and PF performance on injection molding machines (K-TEC 275 form Ferromatik Milacron in Germany) with a focus to locate, within a machine, various measures that could improve energy use in the plastics industry, in this case RostiGP in Gislaved. These measurements have been carried out with the help of a power quality clamp meter to carry out time logs of the machines for some time during normal word rate.
Wireless Trailer Connection
Today's communication solution between the vehicle and trailer is one many see as anon-viable solution, then breakdowns on both the lights and cables are common. Now, anew innovation enters the market, a system that can transmit wireless control signalsbetween the vehicle and trailer.Parvus and Zap, the two solutions that the projekt group has come up with during thisthesis work carried out over the last year on Utvecklingsingenjörsprogrammet.Technologists Peter Jägevall and Christopher Åberg has developed this project on theirown. The group has developed various concepts and chosen to work on, two of them.The project has resulted in this report and a prototypeThe solution that the group has developed is a wireless communication between vehicleand trailer. The project team has developed new power-efficient LED lighting fixtures inorder to implement an internal power source in the trailer. The result of this has becomea maintenance-free and wireless product to trailers.
E-BUSINESS, WHAT IS IT GOOD FOR: AN EXPLANATORY STUDY OF FIVE COMPANIES? E-BUSINESS SOLUTIONS
The notion of firms interacting with technology is not new; these types of systems were already in place in the mid eighties. E-business users worked with connections between their inbound logistics and procurement systems, and suppliers? order-entry systems. When these connections were described for the first time the vertical links between two, or more, value chains in a value system received more attention in firm strategy. The design of the linkages in the value system was said to be a product of the need for coordination and relative bargaining power.
Voltage Sags Indices and Statistics
Voltage sag indices are a way of quantifying the performance of the power supply, as far as voltage sags are concerned. Indices can be defined for individual events, for individual sites, and for a whole system. A standard method for single-event methods is part of IEC standard 61000-4-30.This thesis emphasizes the importance of voltage sag indices and different methods for calculating three-phase voltage sag characteristics. Three-phase events measured in a medium network voltage over period of one month were analyzed, results examined and statistically evaluated. An algorithm for calculating voltage sag characteristics and indices was created in Matlab.
Microstrip Solutions for Innovative Microwave Feed Systems
This report is introduced with a presentation of fundamental electromagnetic theories, which have helped a lot in the achievement of methods for calculation and design of microstrip transmission lines and circulators. The used software for the work is also based on these theories. General considerations when designing microstrip solutions, such as different types of transmission lines and circulators, are then presented. Especially the design steps for microstrip lines, which have been used in this project, are described. Discontinuities, like bends of microstrip lines, are treated and simulated.
Gage R&R studie på mätutrustning för förpackningsavstånd
The aim of the thesis is to analyse and understand resolution, repeatability and reproducibility of the measurement system for package distance. The measurement system for package distance is already in use, no Gage R&R has been performed on the system and before spreading use of the system the quality of the system has to be understood and approved.
Utformning av förskolans inomhusmiljö utifrån ett genuspersketiv.
The purpose of this thesis was to examine the ways in which the constructions of heterosexuality and gender in three Disney movies about princesses affect the power relations between men and women in the movies, and how discourses on gender and heterosexuality have changed over time. Research questions were:How do characters in the movies talk about gender and heterosexuality?How does the interplay between gender and heterosexuality affect the power relations between men and women in the movies?What are the likenesses and differences between movies from different time periods?Discourses were mapped out using a model based on Ernesto Laclau and Chantal Mouffe?s political theories. These discourses were then analyzed with a theoretical framework consisting of Yvonne Hirdman?s concept of gender system and gender contracts, Judith Butler?s view on the heterosexual matrix and an understanding of power relations based on Michel Foucault.
Koldioxidutsläpp vid sticklingsproduktion av pelargonium x hortorum i Kenya jämfört med Sverige :
Long transport of products is an environmental issue discussed to an increasing extent. The consumers are increasingly aware of how far our comestibles really have been transported. The increasing levels of environmental emissions are something that concerns people. The question is nevertheless delicate and many choose to ignore it. This is no longer an option.