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3523 Uppsatser om Frequency inverter control - Sida 8 av 235

Konstruktion av turbinmodell för kaplanturbiner

Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.

Synchronous Latency Insensitive Design in FPGA

A design methodology to mitigate timing problems due to long wire delays is proposed. The timing problems are taking care of at architecture level instead of layout level in this design method so that no change is needed when the whole design goes to backend design. Hence design iterations are avoided by using this design methodology. The proposed design method is based on STARI architecture, and a novel initialization mechanism is proposed in this paper. Low frequency global clock is used to synchronize the communication and PLLs are used to provide high frequency working clocks.

När gränsen för styrning suddas ut - En fallstudie av hur ett företags styrning påverkar dess kundrelationer

As collaboration between companies move beyond the single transaction into more long-term relationships the consequences of a company's control system become more complex. The aim of this paper is to provide an understanding of how intra- and inter-organizational control and work practices interact through examining how a company's intra-organizational control influences its customer relationships. The empirical research is performed through a qualitative case study where interviews have been conducted with management and sales staff within the case company as well as with one of the customers. The empirical findings have been analyzed using frameworks and theories regarding management control and customer relationships. The study reveals that the intra-organizational control of the case company affects its relationships with customers in a number of ways.

Pilotmodeller till flygmekanisk simulator för JAS 39 Gripen

AbstractSAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ?Aircraft Rigid body Engineering Simulation?. To work with these pilot models has been both time-consuming and inefficient.

Volymsrapportering vid drivningsarbete

Reporting harvested and forwarded volumes are important for the forest industry as it provides information of the size of the stock and facilitates logistics. Figures from Holmen Skog show low reporting frequency. The purpose of this study is to investigate the reason and find suggestions for improvement. A total of 17 machine operators were interviewed using a questionnaire combined with open questions. The results show that the majority of the machine operators find it simple to use the reporting system, although, some of them reports that it doesn?t always work as supposed to.

Automatisering av spraytorkningsprocess

ABB Surge Arrestors in Ludvika have for a long time had a problem to keep the moisture at a steady state in the production of their ZnO-powder, that is used to produce varistors.Some black-box models of the spray drying process have been designed and evaluated to find a solution for the problem. After evaluating the collected data it has been found that variations in the supply voltage causes control difficulties for the operator. A cascade control system was designed, consisting of three PI control loops designed with lambda tuning. The disturbance in the supply voltagewas used as a feed forward in the control system.At the end of the project the control system was installed, and tests were made to verify the functionality of the regulator. It was shown that most of the variations in the moisture of the powder could be eliminated using small resources, through purchase of a process controller and four power meters.

Locus of Controls inverkan på strategier för konflikthantering i kärleksrelationer

Syftet var att undersöka om personers Locus of Control påverkar deras konflikthanteringsstrategier i kärleksrelationer. Hypoteserna var: H1: Det finns skillnader mellan personer med extern och intern Locus of Control när det gäller vilka typer av strategier de använder för att hantera kärleksrelationsproblem. H2: Personer med intern Locus of Control har större benägenhet att använda sig av relationskonflikthanteringsstrategin Kompromiss i sina kärleksrelationer. H3: Kvinnor påverkas mer än män av Locus of Control när det gäller vilka typer av strategier de använder för att hantera kärleksrelationsproblem. Deltagarna var 172 studenter.

Styrreglage för hållbarhetsstyrning - En fallstudie av hur företags interna styrning aktiverar Levers of Control för att uppfylla hållbarhetskrav

The connection between management control systems for controlling sustainability and a firm's motivation for engaging in sustainability is not completely understood (Arjaliès & Mundy, 2013). The aim of this thesis is to develop a more profound understanding for management control in achieving sustainable companies. To do this, we raise the question: How and to what extent do companies use management control systems to achieve sustainability compliance Simons's Levers of Control (1995) are applied to this question in order to get a consistent and thorough insight of management control systems. Hence, a case study of ABB:s work to achieve material compliance in accordance with EU-regulation was conducted. The findings of the case study reveal that ABB uses the regulations as explicit goals and implement them in sustainability procedures.

Triac Driver Platform

In the electronic industrials, power control of AC motors is commonly used. For example power control of a washing machine motor, a vacuum cleaner motor or a coffee machine motor. The company Rejlers Ingenjörer AB has many projects where power control of AC motors is included. A prototype card for this task can save time and money for the company in the future and this is the reason for this thesis.The motors are power controlled by a TRIAC and control of the trigging pulses to the TRIAC. This card is modularly built and can easily be adapted for future projects where the power control of AC motors are included.The prototype card can be used as a subsystem in a larger electronics projects or as it is in lab environment for testing and evaluating new motors..

Automatisk nivåreglering av strålkastare

To be allowed to sell Z-suspended vehicles with dipped beam Xenon or LED lighting, Scania have to develop automatic headlight level control. This master?s thesis aims to be the foundation to that development.The thesis consists of several parts; a market analysis of how competitors to Scania and the general vehicle industry solve this problem; several available principles for detecting the amount of control needed; the construction of a test station for sensors, a control unit and components connected controlled by the control unit; a further theoretical and practical development of one principle ? one rotational sensor connected between the chassis and the back drive axis; a state flow model programmed in Simulink that produces the control signal for the headlight leveling from the sensor input.Lastly the thesis gives some recommendations to the further development and implementation of automatic headlight level control on Scania vehicles..

Validering av den svenska översättningen av Impaired control scale ? självskattningsskala som undersöker kontroll av alkoholkonsumtion

Föreliggande studies syfte var att undersöka validitet och intern konsistens för den svenska översättningen av Impaired control scale (ICS), en självskattningsskala som mäter grad av kontroll av alkoholkonsumtion. ICS består av subskalorna; Attempt control (AC), Failed control (FC) samt Predicted control (PC). Svar på ICS sammanställdes från respondenter (n = 203) som behandlats för alkoholproblem vid mottagningar i Västra Götaland. Faktoranalysen visade en bakomliggande faktor för AC, och två faktorer för FC respektive PC. Den interna konsistensen var god.

Testsystem för utredning av integrerad styrning för RC-helikopter

AbstractThis report is about the creation of a test system for development of a control system for a off the shelf RC-helicopter, which can be bought for about two thousand SEK. The test system consists of both electronics for controlling the helicopter and mechanical constrainer. The constrainer is used for mounting the helicopter so that it won´t crash.A circuit board including processor and sensors was manufactured. This was used for doing test of the different control algorithms. In this way were we able to analyze the quality of the sensors chosen, and what other sensors that could contribute to the control of the system.Basic helicopter control have been studied and presented in the report.

EKONOMISTYRNING I EN MOTORVERKSTAD: En analys av centralt ställda krav ur ett operationellt perspektiv

The purpose of this thesis is to analyze the design and function of an engine production management?s control system and its intended function, and to contrast it with the present management control systems in use on an operational level. Interviews conducted with employees from all levels of the engine production are the main source of this study?s empirical foundation. Information has also been gathered from relevant written material such as annual reports, internal documents etc.

Utveckling av I/O-modul för trafikskyltsystem

This thesis has been carried out in collaboration with LEDtec International AB. LEDtec focuses on innovative solutions in LED screens. Everything from large advertising signs to welcome signs in cities, to screens indicating speeds or warning of heavy traffic. The task was to was to help them develop a new version of the control board that is used in some of their products. The reason for this is that their old control board is obsolete and the components that are on it, is no longer manufactured or in need to be renewed.

Minkvalpars beteende i större berikade burar vid olika gruppstorlek :

Farmed mink often perform stereotypic behaviours which is considered to be a sign of reduced welfare. Previous studies have shown that enriched cages can reduce the frequency of performed stereotypies. Most studies on mink in Sweden have been done on adults. The aim of this study was to investigate if larger enriched cages with two or four mink kits reduce stereotypies in mink kits during their growth period in comparison to traditional cages. In the present study the behaviours of mink kits that were kept in four different treatments at a private mink farm were recorded. Traditional cages with two mink kits were used as a reference and the other treatments consisted of larger cages with shelves with two kits, larger cages with shelves and a plastic cylinder with two kits, and larger cages with shelves with four kits.

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