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2536 Uppsatser om Current measuring - Sida 6 av 170
Utveckling av Mätmetoder för Färdmotstånd
The student project Elba at KTH started in 2011 and is a project where a battery driven prototype car is developed. The vehicle competes in Eco Shell Marathon in Rotterdam, Holland. In this competition the vehicle that travels a certain distance including several starts and stops with the lowest energy consumption wins. To minimize the consumption is therefore very important, which requires knowledge of the vehicles energy losses.A vehicle's energy losses depends on several factors and can be divided into the powertrain efficiency and the driving resistance. The driving resistance can then be divided in to rolling and air resistance, if smaller losses like vibrations are ignored.
Avfyrnings-/relälåda
This is a report of our examination project in electronics carried out for Bofors Test Center in Karlskoga. The task was to construct an electronic devise for starting up different kinds of measuring systems in exact time during test sequences. The modules that are used today are old and unreliable. Our goal was to construct a prototype, which later on is supposed to be developed into a useful system..
Framtagning av reläskyddsinställningar för en transformatorstation
A substation must be properly protected against lightning and other external effects to the equipment in the station or staff, for that we use relay protection. They should also protect against internal errors which may occur as ground faults. There are different types of protection relays, but most common are overcurrent-, distance-, residual current- and differential protection.The purpose of this thesis was to deepen our knowledge of relay protection and to use the theoretical knowledge we got from the university studies in the work process. In the process we discovered which parameters were the most essential and calculated these for all relay protections on the substation. We also carry out a comparison between two brands of relay protection, ABB and Alstom.During our work we will test and simulate the over-current relays in a program called NEPLAN, the program will also calculate the fault currents.
RCC-Jordfelsskydd, mätmodul för övertonsanalys
The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.
Planseparerad spårtrafik i Göteborg
The City of Gothenburg has an urgent need to upgrade its public transport. The capacity of its light rail transit (LRT) has reached maximum capacity within the inner city limits years ago. The construction of an underground metro will be very expensive and time consuming due to the soft clay beneath the city. The apparent need of developing another type of mass rapid transit (MRT) is urgent. An elevated metro have turned out to be a success in Greater Vancouver, but is it possible for the system to operate well in Gothenburg with its narrow streets and current land use; will its route coexist with the current LRT or will the noise disturb people too much?.
Analys av mätdata från nätstationer
Fortum has in a pilot project installed metering equipment with wireless communication in secondary substations in Stockholm. So far, the collected data are used only in specific projects.This master thesis was carried out at Fortum Distribution AB in Stockholm during 2013. The purpose of this study is to simplify and enhance the use of data in for example network planning process, by giving suggestions on how data can be managed and giving examples of analyzes that collected data can be used for.The electricity meter which Fortum has installed is a EDMI-Mk10A which is set to measure max/average/min values with a one hour time resolution of the following parameters: voltage (per phase), current (per phase) andactive power and active and reactive energy.In order to analyze the collected data an analysis tool is required. During this thesis two customized tools in Microsoft Excel have been developed, one for sorting data and one for analyzing.One aim of the thesis is to show examples of what collected measurement data can be used for. This work shows an example of analysis of active power, power factor, voltage, occurrence of interrupts and the relationship between outdoor temperature and power.This master thesis has among others resulted in the following advice: Expand the number of secondary substations with measuring equipment.
Ett flervariabelt feldetekteringssystem för övervakning av bärlagertemperaturen i vattenkraftturbiner
The purpose of this thesis work was to develop an automatic fault detection system for surveillance of bearing temperature in hydropower turbines. The parameters used except the bearing temperature were cooling water temperature and cooling water flow. A simple static model based on data sampled every minute was developed to estimate the bearing temperature. Then a detector for detection of change in bearing temperature based on the CUSUM-algorithm was designed. Since the amount of data was very small the developed model was too uncertain to be used in a working system.The designed fault detection system showed to work well for the available data.
Fåglar i urbana miljöer : kvaliteten på urbana habitat och om beståndstäthet är ett bra mått på habitatkvalitet
The urbanization of the world is increasing. How it affects bird populations have been well studied during the last decade, and comparisons between urban and non-urban habitats have been carried out. A common method for measuring habitat quality is to calculate the population density. This method is easy to use, but have been criticized during the last couple of years. In this study, data of population densities was compared with data on reproduction success.
Artikelbundna instruktioner : Layout och rutiner
This thesis is carried out on behalf of watermixer manufacturer Ostnor AB in Mora.The thesis deals with the area of Article Bound Instructions (ABI) at the company'sassembly department, regarding the layout and management routines involved withthese instructions.In the current situation there are problems with no uniformity in the manner in whichthe ABI is written, then referred to both the civil structure, images and specificityrates in the text.Another problem is that operators do not make use of the ABI that are available inthe current situation, and that there are no clear procedures for who has theresponsibility to write, update and change these ABI.During this work has several people that were identified as key personnel of thethesis held in order to get a handle on how the current situation of the variousobjects of the work looks like, and to examine different desires about the future ofthese should look like from the different subjects perspectives been interviewed.During the work, a number of deficiencies, including that the current program that isused to write the ABI, Lotus Notes, do not possess near the prerequisites for being asimple program to deal with when writing the ABI, which is a condition since wishesare about to put the responsibility for the ABI generation to the departmentsoperators, since their main task is to assemble and do not bother with a program in acomputer.The result of this work has generated new layout and structure of the ABI, designedto be used continuously in the assembly for evaluation, routines regardingresponsibility of the ABI for the Department of Production Engineering (PT),procedures for how the ABI should be written regarding amount of detaileddescriptions in the text and use of pictures.In addition, proposals for further work and improvements has been developed basedon experience during the work and presented at the end of the report..
Luftutsläpp från järnmalmsproduktion : - Strategier för systematisk luftkvalitetsmätning
The mining company LKAB extracts iron ore in three areas in the north of Sweden, Kiruna, Malmberget and Svappavaara. The iron ore is refined and in the pelletizing plants the material is rolled to finished pellet product. The different steps of pelletizing plants causes among other things emissions to the air. It occurs occasionally stops in the production and the emissions are vented via an emergency chimney without purification. The aim for this work is to look into how LKAB may improve their monitoring of air emissions and control of ambient air quality and the analysis methods which are suitable for measuring.
Konstruktion av UPS-modul
This master thesis describes the development of an UPS module. UPS is an acronym for Uninterruptable Power Supply. The UPS module has been developed at the company AerotechTelub AB. The UPS module delivers the necessary voltage and current in case of a power interrupt. If a power interrupt occur, the computer system has one to three minutes available to store data and shut down correctly.
Värmeåtervinning ur spillvatten. En utredning av möjligheterna med spillvattenvärmeväxlare.
This thesis is carried out on behalf of watermixer manufacturer Ostnor AB in Mora.The thesis deals with the area of Article Bound Instructions (ABI) at the company'sassembly department, regarding the layout and management routines involved withthese instructions.In the current situation there are problems with no uniformity in the manner in whichthe ABI is written, then referred to both the civil structure, images and specificityrates in the text.Another problem is that operators do not make use of the ABI that are available inthe current situation, and that there are no clear procedures for who has theresponsibility to write, update and change these ABI.During this work has several people that were identified as key personnel of thethesis held in order to get a handle on how the current situation of the variousobjects of the work looks like, and to examine different desires about the future ofthese should look like from the different subjects perspectives been interviewed.During the work, a number of deficiencies, including that the current program that isused to write the ABI, Lotus Notes, do not possess near the prerequisites for being asimple program to deal with when writing the ABI, which is a condition since wishesare about to put the responsibility for the ABI generation to the departmentsoperators, since their main task is to assemble and do not bother with a program in acomputer.The result of this work has generated new layout and structure of the ABI, designedto be used continuously in the assembly for evaluation, routines regardingresponsibility of the ABI for the Department of Production Engineering (PT),procedures for how the ABI should be written regarding amount of detaileddescriptions in the text and use of pictures.In addition, proposals for further work and improvements has been developed basedon experience during the work and presented at the end of the report..
Accelerometertillbehör till mobiltelefon : - Utveckling av Blåtands ansluten accelerometermodul till smartphone
This master thesis has been carried out as a prototype development project. The project hasbeen performed in cooperation with ÅF Combra AB. The purpose with the master thesis is toconstruct a Bluetooth interface between an accelerometer and a smartphone and constructinga physical prototype containing an accelerometer. This is done to test a new user interface tomobile phones. The master thesis has also included a research about the possibility toimplement distance measuring with Bluetooth.
Konstruktion av Industriellt Vibrationsmätningssystem med signalbehandling baserad på Digitala Vågfilter av Lattice-struktur
In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box.
Från engagemang till intention - En kvantitativ studie om sambanden mellan engagemang och konsumenters intention att använda detaljisters smartphone-applikationer
Smartphone applications, or apps, are an increasingly important part of omnichannel retailing. While the adoption and usage of apps for communicating with consumers has grown exponentially over the past few years, there is little academic research in this area. The primary purpose of this thesis is to describe how the involvement in a product category affects consumers' intention to use a retailer-branded smartphone application during their shopping trip. Drawing upon recent IS-literature with models TAM and UTAUT, our results indicate that product category involvement constitutes an important factor on the intention to use a retailer-branded smartphone application. By viewing involvement as a multidimensional construct, our study shows that the degree of hedonic and expressive value a product cateogry provides consumers with has important effects on intention, and these relationships are not moderated by consumers' age.