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3101 Uppsatser om Control stability - Sida 2 av 207

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.

Samverkande, motverkande eller kompletterande? : En uppsats om relationer mellan styrsystem

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..

Uljabuouda vindkraftpark turbinmodellering och stabilitetsanalys

This master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor.

KRAV OCH MÖJLIGHETER FÖR STYRNING AV VATTENFALLS VATTENKRAFTSTATIONER

The secondary control must be part of the production plan, since the capacity will bedeployed in advance, just as the primary control. The activation of the new frequencycontrol should be preformed in Vattenfall's operations centers (DC) to minimizecommunication delay. Vattenfall needs to work towards a more holistic optimizationsystem. The main issue for Vattenfall Generation is not how we produce but ratherwhen, which is done with creation of bids. This is where there is the mostopportunity for improvement.

Effekten av syskonplacering på Health Locus of Control : En studie om syskonplacering och kön kan relateras med locus of control ur ett hälsoperspektiv

Studier har visat att det finns ett samband mellan syskonplacering och locus of control, medan andra studier inte funnit något samband. Syftet med denna studie är att undersöka relationen mellan syskonplacering, kön och locus of control ur ett hälsoperspektiv hos gymnasieelever i årskurs 3. I undersökningen deltog 147 gymnasielever ifrån fem skolor i Kronobergs län. Resultatet visade att kön och syskonplacering samvarierade med intern health locus of control (F= 3,01;p< 0,03; ES= 6,2) och att syskonplacering och kön tillsammans inte visade någon signifikant inverkan på extern health locus of control (F= 2,20;p=<0,09; ES= 4,6). Fyndet kan indikera att manliga mellanbarn i större utsträckning strävar efter en intern health locus of control än kvinnliga mellanbarn.Nyckelord: Syskonplacering, health locus of control, intern- och extern locus of control, kön..

Utveckling av styrsystem för EMC-kammare

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

En frivillig standards kvalitetsma?ssiga pa?verkan pa? redovisning av varuma?rken : ISO 10668

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..

"Den som är satt i skuld är icke fri" : En studie om de svenska elnätsföretagens kapitalstrukturer

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..

En studie om artikelhantering i material- och produktionsstyrningssystem på System Andersson AB

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Adaptiv temperaturreglering av bostadshus

The control of indoor temperature must be able to handle large time constants and both measureable disturbances like outdoor temperature, and non-measurable disturbances, like waste heat from appliances. Due to cheaper microcontrollers (small computers with designated tasks) with better performance, more advanced and computation-demanding methods for control can be used.In this thesis, Generalized Predictive Control (GPC) has been implemented and tested on a theoretically derived model of a house. GPC states that a model of the system is estimated in every sample, and the control is carried out simultaneously, based on predictions of the model. Disturbances like solar radiation can be estimated and used in the control as well. The control signals are determined by quadratic programming, which makes it possible to consider conditions, for example limitations on the control signals.GPC requires a number of parameters to be defined, like model order and control signal penalty, but is relatively robust for variations in them.

STABILITET I INSOMNI, ÅNGEST, DEPRESSION OCH UTBRÄNDHET OCH RELATIONERNA TILLSTÅNDEN EMELLAN

Mental illness is today the leading cause of long-term sick leave and insomnia, anxiety, depression and burnout are among the most common conditions. The aim of the study was to investigate the stability of these conditions and how this is influenced by gender and age, as well as the extent to which these states are risk factors for each other. The participants were a random sample (n = 2336) from the general population in the age of 18-79 years. The results showed that stable illness was more common among women than men, and that stable illness decreased with aging. The stability itself was not affected by gender or age. Relations between the conditions were bidirectional and they constitute major risk factors for each other (odds ratios, OK = 2.37 to 6.46). The largest risk factor for a condition is, however, previous occurrence of the same problem. Previous burnout was found to be a significantly larger risk factor for future burnout than previous insomnia for future insomnia (OK = 9.63 and 5.74, respectively). The results suggest that insomnia, anxiety, depression and burnout, despite their differences, are similar regarding symptoms and underlying causes. The importance of early interventions to prevent comorbid conditions which are more complicated and more difficult to treat is emphasized..

Traditionell ekonomistyrning vs modern verksamhetsstyrning - en fallstudie av ett växande företagsstyrfilosofi

The purpose with this paper is that trough a description of the management control at Jitech AB find out if traditional management control have been abandoned for benefit for modern management control and in which extent the transition have happened. Further is the second purpose with this paper to find out which decisions that lies behind the design of the management control and how these are in opposition to with the theory..

Reliabilitetstest på balanstesterna Unilateral stance och Limits of stability

Människans balanssinne är ett av våra viktigaste sinnen som dagligen sätts på stora prov då vi som tvåbenta individer ska upprätthålla kroppen i normal position vid rörelser och aktiviteter. Människans balans bygger på tre olika sensoriska system som arbetar i synergi för att upprätthålla kroppen i en bra position. Balance Master är ett mätinstrument för att mäta människans posturala kontroll. Syfte: Studiens syfte var att undersöka reliabiliteten i balanstesterna Unilateral stance och Limits of stability utförda på en Neurocom balance master över bestämd tid på friska individer. Material/metod: 11 friska försökspersoner mellan 23 och 29 år utförde balanstesterna Limits of stability och Unilateral stance vid fyra olika testtillfällen.

Missilstyrning med Model Predictive Control

This thesis has been conducted at Saab Bofors Dynamics AB. The purpose was to investigate if a non-linear missile model could be stabilized when the optimal control signal is computed considering constraints on the control input. This is particularly interesting because the missile is controlled with rudders that have physical bounds. This strategy is called Model Predictive Control. Simulations are conducted to compare this strategy with others; firstly simulations with step responses and secondly simulations when the missile is supposed to hit a moving target.

Yeast in forage crops and silage aerobic stability at 15 Swedish dairy farms

This study investigates the role of yeast in green crop and its impact on the aerobic stability of silage. Fresh crop was collected from 15 farms in southern and middle parts of Sweden during the summer 2014; samples from the primary harvest was collected from eight farms and samples from the first regrowth harvest was collected from seven farms. The grass was ensiled in 1.7 l glass silos. After three months of ensiling, silos were opened and silages were stored aerobically for 10 days. Samples from both harvests were ensiled in completely airtight silos, but samples from the second harvest were also ensiled in slightly ventilated silos. Chemical analyses and yeast counts were performed for fresh crop and silage.

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