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1571 Uppsatser om Variable speed motor operations - Sida 1 av 105

Energieffektivisering på Skutskärs Bruk : Varvtalsstyrning till utvalda pumpenheter på Blekeri 4

In modern society in terms of economics and environmental impact, it is important to ensure that a company is as energy efficient as possible to reduce the amount of energy used. About 10 TWh of electricity used annually to pump drives in Swedish industry. Therefore, pumping system has great potential for energy savings.The objective of this report was to determine how much energy and money that can be saved with the insertion of variable speed drive to six pumps on Bleach plant 4 in Skutskär Mill. The work was performed with electrical measurements during one week, analysis of pump curves and the compilation of production data over a year.The results show that four of these six pumps were profitable and yielded an annual saving of 1172 MWh of electricity and 560 000 SEK. With an economic lifetime of 10 years and a discount rate of 6.8% the final result for the entire life-cycle savings became 3 355 000 SEK.

Automatisk trimning av drivsystemreglering från MATLAB

This master thesis covers the development of an automatic tuning process for the existing speed controller for drive systems. The drive systems are resonant two-mass systems where a motor is used to drive a load connected by a shaft. The developed method relies heavily on system identification and the construction of a complete mechanical model of the process. With this approach, the common problem with poor load speed control that derives from measuring only the motor speed can be addressed and solved for a majority of such processes.The automatic tuning method has along with general test functions been implemented in a complete tool for automatic tuning, testing and performance evaluation and reporting for drive systems..

Konceptstudie av drivmodul till bandskotare med hybriddrift

BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.

Stereoseende i realtid

In this thesis, two real-time stereo methods have been implemented and evaluated. The first one is based on blockmatching and the second one is based on local phase. The goal was to be able to run the algorithms at real-time and examine which one is best. The blockmatching method performed better than the phase based method, both in speed and accuracy. SIMD operations (Single Instruction Multiple Data) have been used in the processor giving a speed boost by a factor of two..

Wobblerpump

The task was to design and manufacture a submersible displacement pump working with the wobble plate principle. The main task for the Wobble plate pump is to be used as a sewage pump for smaller households or dewatering pump in environments where small flows and high pressures are acquired. For these purposes ITT Flygt sell a screw pump, PC-Grinder 3068. The hydraulic part of the PC-Grinder is manufactured by a subcontractor. Therefore ITT Flygt wants to evaluate an alternative to their screwpump PC-Grinder, which can be entirely manufactured by them self.

Lyckans land? : En ekonometrisk studie över nationshemvistens påverkan på upplevd lycka.

Does the country people live in affect the probability of them experiencing happiness? Can a country variable in an ordinal regression model be affected when microeconomic and macroeconomic factors are added to the model? The possible outcomes are either that the country variable affects less when the additional predictors are added to the model, or that they stay the same. The micro data is collected from the European Social Survey database, the macro data is collected from the World Bank. The country variable becomes less substantial when additional variables are added to the model. The variable with the most influence over expected happiness apart from the country variable is whether the individual often socializes with friends or not.

Aktivering av trafiksäkerhetskameror : En studie av kameraaktiveringens effekter på fordonshastigheter i Sverige

During 2006 an estimated number of 150 persons are supposed to have been killed in road accidents caused by speed limit violations. Through Automatic traffic security control (ATK) the Swedish road administration (Vägverket) is working towards lowering the number of speed related accidents. By placing the speed cameras on roads they've managed to lower the average speed at those places. The enlargement of the number of speed cameras is based upon knowledge about for example how high the risk is for speed related accidents on the roads. The speed cameras always measure the speed in which every vehicle passes, but aren't constantly activated to register speed violations.

Fortkörning - en inkomstfråga? : En studie utav inkomstens påverkan på benägenheten att köra för fort

The purpose of the thesis is to investigate whether a higher income make individuals more likely to exceed the speed limit. In addition to income the variables age, sex, perception of the speed of the average driver and offense history for the last three years are taken into account.The method used is based on a survey performed at the mandatory annual motor-vehicle inspection (Bilprovningen). 177 individuals were asked to participate, of these, 124 completed the survey which in turn left us with 117 usable observations.The analysis is based on two forms of regression, a linear regression and an ordered logit regression to confirm the results for the ordinal data.The final model indicates a result where income and age are statistically significant. Sex is considered insignificant for our data material and is excluded from the model. Age has a negative effect on the propensity to exceed the speed limit while income has a positive effect.

Parallell beräkning av omslutande volymer

This paper presents techniques for speeding up commonly used algorithms forbounding volume (BV) computation, such as the AABB, sphere and k-DOP. Byexploiting the possibilities of parallelismin modern processors, the result exceedsthe expected theoretical result. The methods focus on data-level-parallelism(DLP) using Intel?s SSE instructions, for operations on 4 parallel independentsingle precision floating point values, with a theoretical speed-up factor of 4 ondata throughput. Still, a speed-up between 7?9 are shown in the computation ofAABBs and k-DOPs.

Elkvalitéproblem vid varvtalsstyrd motordrift i industrimiljö

Övertoner orsakade av varvtalsstyrda motordrifter ger problem i industrisystem. Syftet med studien är att identifiera problemen och ge rekommendationer för att undvika dem. Studien utfördes som examensjobb på KTH för konsultföretaget Ramböll. En litteraturstudie i ämnet kombinerades med elkvalitémätningar på drifter hos Sandvik Mining.Elkvalitéproblem orsakade av varvtalsstyrda motordrifter kommer till stor del av att frekvensstyrningen ger olinjärt strömuttag som, om nätet inte är tillräckligt starkt, påverkar spänningskvalitén. Problemen kan vara driftstopp, störd utrustning och ökat slitage på utrustning för att nämna några.Denna studie visar att vid ändringar i system innehållande övertoner kan framtida övertonshalter approximeras för vissa fall.

Styrtransmission för bandfordon

The purpose of this master thesis is to construct a steering transmission, for a trackedvehicle, containing two hydraulic circuits which are connected. The steeringtransmission should be mechanical to avoid steer-by-wire.BAE Systems Hägglunds has in an earlier study examined a system with two hydraulicpumps and one hydraulic motor, but the safety of the system wasn?t sufficient.To achieve sufficient redundancy there must be two hydraulic motors, which arecontrolled separately. When the two systems are connected in one point, this point is acritical part of the system because it directly affects both circuits. If one of the hydrauliccircuits fails the other should be able to operate independently as a steeringtransmission.

Motorikens betydelse för inlärning

AbstractMy purpose with this study is to find out if it helps children who have diffuculties with their concentration if they get to practise their motor behaviour knowledge during their day at the school to promote their learning capacity. My purpose is also to find out how schools works with motor behaviour training. To get answers to my questions have I done interviews with four educationalists and I have also used books and internet sites. Motor behaviour is of importance to how children learn things in the school, without a well working motor children gets difficulties to sit still and to concentrate. The children may put their energy at the wrong things in the classroom, when the energy instead should be need to learning things.

Effektiviseringspotential inom industrisektorn : Energibesparing vid frekvensstyrning av centrifugalpumpar ? en fallstudie

The project was performed at SiemensIndustry Drive Technologies with theobjective to provide actual values forthe energy savings potential withinSiemens scope of practice.In Sweden the electrical drives standfor about 30 % of the total electricityconsumption and about 60 % of theelectricity consumption within theindustry. During the pre-study phaseelectrical drives with pump applicationswere identified as large energy users.Because of this a case study at one ofSiemens customers, Stora Enso Fors wasperformed. The system that was evaluatedduring the case study was a throttledsystem with a centrifugal pump forpumping pulp.The results yielded that a saving ofover 50 % could be achieved by replacingthe throttle valve with a variable speeddrive, a frequency converter. Thepayback period was two years and twomonths and the present value for thetotal life cycle cost of the variablespeed system was 662.566 SEK lower thanfor the throttled system. As aconsequence, Stora Enso Fors is advisedto invest in a frequency converter forregulation of the system.The general conclusion is that a focuson system efficiency is the mostimportant factor in energy efficiencyprojects and that the system regulationmethod has a large impact on the overallsystem losses and hence its efficiency.Energy efficiency potential forthrottled systems with centrifugal pumpsis large and significant economicalsavings can be made through investmentswith short payback time..

Motor till unikt luftvärmeväxlarsystem

Gtherm is an innovation company who has an unique air heat exchanger underdevelopment. The purpose of this thesis is to provide data of suitable motors for theheat exchanger and to find suitable motor suppliers.A motor specification was designed. It is an important basis for the search of suitablemotors. A compilation was made of nine motor suppliers and the suitable motorsfrom those. The compilation can be used by GTherm in their choice of suppliers andmotors.The compilation of the demands on the motor and analysis of suppliers indicated thatthere were no standard motors available to GTherms air heat exchanger.

VD:s incitament i form av rörliga ersättningar och dess påverkan på bolagets riskexponering: En empirisk studie av svenska bolag listade på Nasdaq OMX

The recent financial crisis has entailed in a fierce debate whether CEOs variable remuneration has caused unsound risk exposure in public companies. Hence it is considered as interesting to elucidate if this connection exists empirically. With grounding in principal-agent theory, and its implicit assumption of risk adverse agents, this study aims to find empirical evidence for a positively correlated relationship between CEOs variable remuneration and company risk exposure. Through a regression analysis of multidimensional data from 102 listed Swedish companies during the period of 2000-2009, we show that the relationship between CEOs variable remuneration and company risk, in contrast to our expectations, is significantly negative. The coherent result is interpreted as the inherent risk in companies seems to explain the usage of variable remuneration for CEO, rather than vice versa.

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