Sökresultat:
110 Uppsatser om Faults - Sida 5 av 8
Effektivisering av kvävereduktionen i en konstruerad våtmark avsedd att behandla avloppsvatten
On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.
Utvärdering av Raman- och IR-spektroskopi, differentiell svepkalorimetri och dielektrisk spektroskopi för materialstudier på choklad
On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.
Bärighetskontroll av obundna granular material. En jämförelse mellan olika bärighetskontroller samt en alternativ utvärderingsmetod av bärighet med Lätt Fallvikt
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.
Funktionell testning av webbplatser : En fallstudie
Websites are often developed by small businesses, organizations or individuals which may lead to that the testing gets left behind; the focus is on getting a finished product that can be deployed as quickly and as cheaply as possible.Functional testing is important also for websites and a variety of aids exist. With the right tools and methods the development work is facilitated, and it leads to products with fewer Faults.This report shows in the form of a case study how an appropriate tool for functional testing can be selected and how it can be used within development of a website. An analysis of the tools available is reported and JSystem is selected as the most appropriate for this case.It turned out that JSystem could not be used fully as intended in terms of deployment, but a well-functioning alternative solution was developed.A number of test cases were created without any unsolvable problems and JSystem performed well. In JSystem test cases in Java are created in Java, which gives a high flexibility..
Quartzene i gips : Densitet och hållfasthet
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.
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.
Läsfrämjande i förändring: Om bibliotek 2.0:s läsfrämjande redskap
The aim of this thesis is to investigate how libraries use thetools and ideas from library 2.0 in their reading promotionwork. We also want to include how librarians motivate thisuse and whatever merits and Faults they encounter. We haveperformed document studies and interviews which we thenanalyzed with qualitative content analysis. Our theoreticframework in this study which we also used as a part of ourcoding scheme in the analysis was a model over the conceptlibrary 2.0 developed by Holmberg, Huvila, Kronquist-Bergand Widén-Wulff. This model describes seven aspects oflibrary 2.0 which is users, participation, library and libraryservice, web and web 2.0, social aspects, technology andinteractivity.
Värdering av anbud vid kommunala upphandlingar av byggprojekt
The thesis deals with evaluation of tenders for communal construction procurement. Each year the public procurement equals the value of millions of Swedish kronors, of which construction projects makes up a large proportion. These projects tend to often exceed their budgets. The aim with the thesis is to investigate if there are Faults in the tender evaluation process. The theoretical framework for the study partly consists of a review on how the communal evaluation work is described in law and practice.
UV-tork - analys av drift :
The company Somas, Säffle, has assigned Fredrik Kjellin the project of finding out how ?KVTF DN250?, one of their own valves, reacts on cutting forces under production. They wish to know if and then how much it?s possible to minimize the wall thickness of the valve with neither plastic nor to big elastic deformations caused by processing.The most critical processes have been identified as rough lathing. The study has shown that the marginal for a wall thickness of two millimeters, to fall short of the yield stress in the most critical process, is good.
Maskinduglighet på planlaserskärare
Lars Höglund AB is one of Scandinavia?s most qualified manufacturers of sheet metal products and provides custom designed products of very detailed precision. One of the main methods of manufacturing is laser cutting. When Lars Höglund AB signed up a new customer, with high demands in tolerances for the products, Lars Höglund AB thought it would be necessary to know the capability of the laser cutting machine. Also the process of how to retrieve this capability was interesting. The capability will be researched for the following elements: Cutting right angles in squares with a corner radius of 1 mmCutting corners which are not right angleCutting of circles with constant radius Measurements were made on 150 pieces of sheet metal details, which had been cut out by the machine. The data from the measurements where later used to study the capability.
Feldetektering för diagnos med differentialgeometriska metoder -en implementering i Mathematica
Diagnosis means detection and isolation of Faults. A model based diagnosis system is built on a mathematical model of the system. The difficulty when constructing the diagnosis system depends om how the model is formulated. In this report, a method is described that rewrites the model on such a form that the construction of the diagnosis algoritm is easy. The model is transformed by two state space transformations and the result will be a system on state space form where one part of the system becomes easy to supervise.
Dimensionering av ventilhus med avseende på skärkrafter
The company Somas, Säffle, has assigned Fredrik Kjellin the project of finding out how ?KVTF DN250?, one of their own valves, reacts on cutting forces under production. They wish to know if and then how much it?s possible to minimize the wall thickness of the valve with neither plastic nor to big elastic deformations caused by processing.The most critical processes have been identified as rough lathing. The study has shown that the marginal for a wall thickness of two millimeters, to fall short of the yield stress in the most critical process, is good.
Fjärrvärmesystem
This is a report written for an examination project C-level, on the subject of energy. The examination project is a product of the FVB Sweden AB (district heating bureau). It started with a meeting with Stefan Jonsson FVB Sweden AB, were he explained the content of the project, and from this a presentation of the problem was made. The problem that needed to be solved was how they could control the valves in the system to provide heating to everyone in the system. The valves are often oversized so the pump in the heating plant would have to be enormous to be able to provide enough flow to be sufficient, if everyone in the system had there valves fully opened. I came up with two solutions to the problem, one was a wireless network that could keep track of the valves and the other solution was an extra sensor that was placed on the radiator.
Energi och klimatanalys O-huset på Campus i Halmstad
AbstractThe indoor environment affects the human performance. Noise pollution, poor lightning and coloring are some of the factors that affect our work performance. The human is also affected by the air change and temperature, these factors are in most buildings possible to adjust and through this make economic savings. To find out about the indoor environment in the O-building a questionnaire was handed out, measurements/surveys and an interview was also made. 108 questionnaires where handed out to employees and students.
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.