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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
691

Energy analysis and cost estimation of a potential On-shore Power Supply system in the Port of Gävle

Gutierrez Saenz, Juan January 2019 (has links)
The Port of Gävle is one of the most important harbours in Sweden as far as size and freight capacity is concerned. Marine traffic is increasing greatly, thus environmental pollution as well as noise and vibrations are of major concern in port cities. Shore to ship power supply systems might be a feasible solution to curtail emissions because the Auxiliary Engines are instead shut down while the ship stays alongside the quay. The literature review shows they are reliable and very appealing in all respects, thereby contributing to sustainable development. Taking into account the kind of vessels that call at the Port of Gävle, a High Voltage Shore Connection is recommendable, in compliance with the International Standards. An own technical survey is developed to gather all the information, as well as personal interviews to collect first-hand data. Technical issues such as the synchronisation procedure and the ground system with regard to safety are briefly discussed. Due to the lack of data, calculations consist of average values: peak and average demand, and fuel consumption during a typical call. Considering updated energy prices for both electricity and fuel, results show that an on‑shore power supply system make energy costs decrease by 71% at berth in comparison with burning marine fuel, which is saved by around 4 tonnes per call. Additionally, up to 5126 tonnes of CO2 are avoided per year, among other pollutants. Shore‑side power has proven to be profitable and appealing to the Port of Gävle; however, vessels need to be retrofitted, which implies relatively high investments. Collaboration agreements and shipping companies’ willingness to undergo changes are key issues that still need to be solved.
692

Analys av reläskyddsinställningar för jordfelsskydd

Edblom, Hampus January 2019 (has links)
Väl inställda reläskydd för ställverk är en nödvändighet för en personoch driftsäker anläggning. Rapportens mål är att undersöka om oriktade skydd med enbart signalering är tillräckligt för att skydda anläggningen som undersöks, och om riktade skydd har fördelen att förbättra felutpekning, minska risken för felaktig funktion eller minska funktionstiden. Anläggningen som undersökts är ett 6,3 kV industrinät med resistansjordning. I rapporten kontrolleras isolationsvärden och strömtoleranser för utrustningen, som sedan jämförs med beräknade spänningar och strömmar vid enfasiga jordfel. Rapporten beskriver också kort riktade skydd och dess funktioner i förhållande till frågeställningen om den eventuella fördelen med riktade skydd. Resultatet blev att överspänningar på grund av jordfel inte är något problem, men felströmmen genom nollpunktsmotståndet är för stor för enbart signalering. Vid stumma jordfel klarar nollpunktsmotståndet av att hantera felströmmen i 30 sekunder, varefter värmeutvecklingen resulterar i att nollpunktmotståndet kopplas bort och anläggningen blir isolerad från nollpunkten. Riktade skydd behövs enligt studien inte i en anläggning som denna. Detta är baserat på att kabelsträckorna är för korta för att orsaka kapacitiva strömmar tillräckligt stora för att felaktig funktion ska uppstå i oriktade skydd, och att nätstrukturen inte genererar strömmar i oväntade riktningar. Rapportens resultat visar att oriktade skydd är tillräckligt men att funktionen bör ställas om till bortkoppling av felande krets. / Well-adjusted relay protection for electrical substations is a necessity for personal safety and reliable operation. The aim of the report is to investigate whether non-directional protection with signaling alone is sufficient to protect the facility being investigated, and if directional protection has the advantage of improving fault detection, reducing the risk of unnecessary operation or reducing the function time. The facility under investigation is a 6.3 kV industrial network with resistance grounding. The report checks the insulation values and current tolerances for the equipment, which are then compared with calculated voltages and currents at single-phase earth faults. The report also briefly describes directional protection and its functions in relation to the issue of the potential benefit of directional protection. The result was that overvoltages due to earth faults are not a problem, but the fault current through the neutral point resistance is too large for signaling alone. In the case of earth faults with very low fault impedance, the neutral point resistance can handle the fault current for 30 seconds. After which the heat development results in the neutral point resistance being disconnected and the facility being isolated from the neutral point. According to the study, targeted protection is not needed in a facility like this. This is based on the fact that the cable paths are too short to cause capacitive currents large enough to cause unnecessary operation in non-directional protection, and that the network structure does not generate currents in unexpected directions. The result of the report shows that non-directional protection is sufficient, but that the operation function should be changed to tripping of faulty circuits
693

Mönsterigenkänning och trendanalys i elnät : Prognostisering av elkvalitet samt effektuttag inom industrin / Pattern recognition and trend analysis in electric power grid : Forecast of power quality and power consumption in industry

Elvelind, Sofia January 2019 (has links)
Intresset för elkvalitet har ökat då elektrisk utrustning, såsom omriktare, numera ger upphov till mer störningar. Elektrisk utrustning har också blivit mer känslig mot störningar samtidigt som industrier har blivit mindre toleranta mot produktionsstörningar. Traditionellt har felhantering i elnät skett när problemet redan uppstått och utgått från historiska data. Metrum har dock genom sin applikation PQ4Cast introducerat mönsterigenkänning för att prognosticera elkvalitetsparametrar samt aktiv effekt och i och med det bidra till ett proaktivt underhåll. Applikationen skapar en prognos för kommande vecka utifrån data för de senaste veckorna, under utveckling är även en funktion för trendanalys av bland annat effektförbrukning och spänningsnivå. Syftet med implementeringen av PQ4Cast är att få en högre tillgänglighet och minimera kostnader för underhåll och oplanerade avbrott. Ett andra syfte är att skapa ökad kontroll över variationer i effektuttag. Målet med detta examensarbete är att avgöra vilka avvikelser som är viktiga för Sandvik att ha kontroll över, ta fram metoder för att utvärdera applikationens funktionalitet samt ge underlag till hur prognoser från applikationen bör hanteras. Utöver det ska även nyttan med funktionen för trendanalys avgöras. Sandvik ser störst nytta med att få kontroll över framtida värden för aktiv effekt, reaktiv effekt samt variationer i spänningens effektivvärde. Av dessa borde variationer i aktiv samt reaktiv effekt vara mest lämpad för PQ4Cast att identifiera. För undersökning av överensstämmelse mellan prognos och verkligt utfall rekommenderas användning av korrelationskoefficient, determinationskoefficient samt signifikansnivå på fem procent. Användning av MAPE, Mean Absolute Percentage Error, rekommenderas också att användas för att kvantifiera prognosfelet. Vid god överensstämmelse rekommenderas prognoserna för aktiv effekt från PQ4Cast användas för veckoprognos till elhandelsbolaget Statkraft i kombination med temperaturprognos samt prognos över produktion kommande veckan. Trendanalysfunktionen visar ett medelfel med några procent för den aktiva effekten. Ytterligare undersökningar av funktionen rekommenderas och vid god överensstämmelse rekommenderas denna användas som grund för prognoser som ges till Statkraft samt används som grund för nytt effektavtal med Vattenfall i kombination med produktionsprognos. För analys av trend för spänningens effektivvärde är avvikelsen från prognosvärdet endast några tiondels procent och här rekommenderas fortsatta undersökningar och då specifikt vid del i nätet där installation av solcellsanläggning planeras. Applikationen PQ4Cast samt trendanalysfunktionen förväntas kunna leda till ekonomiska fördelar i form av minskade kostnader för inköp av el samt minskade elnätsavgifter och även betydande besparingar om störningar som kan leda till avbrott kan upptäckas i tid och avstyras. Kortvariga störningar, såsom spänningsdippar, är dock svåra för PQ4Cast att upptäcka i dagsläget. / Interest in power quality has increased as electrical equipment, such as inverters, nowadays emits more disturbances. Electrical equipment has also become less tolerant to disturbances, while industries have become less tolerant to disturbances in the production. Traditionally, fault diagnosis and handling have been performed when the fault has already arisen and has been based on historical data. Through its application PQ4Cast, Metrum have introduced pattern recognition to forecast power quality parameters and active power, and thereby contribute to proactive maintenance. The application creates a forecast for the coming week based on data for the last few weeks. Under development is also a function for trend analysis of, among other things, power consumption and voltage level. The objective with the implementation of PQ4Cast is to achieve higher availability and minimize costs for maintenance and unplanned interruptions. A second objective is to increase the control over variations in power consumption. The aim of this thesis is to determine which deviations are important for Sandvik, develop methods for evaluating the application’s functionality and provide a basis for how forecasts from the application should be managed. The aim is also to determine the usefulness of the trend analysis function. For Sandvik, the greatest benefit is seen in gaining control over future values for active power, reactive power and variations in the RMS value of the voltage. Of these, variations in active and reactive power should be most suitable for PQ4Cast to identify. For examination of the conformity between prognosis and actual outcome, the use of correlation coefficient, determination coefficient and significance level of five percent is recommended. Use of MAPE, Mean Absolute Percentage Error, is also recommended to quantify the forecast error. In the event of good conformity, the forecasts for active power from PQ4Cast are recommended for weekly forecasts to the electricity trading company, Statkraft, in combination with temperature forecasts and forecasts of production following week. The trend analysis function shows MAPE at a few percent for the active effect. Further investigations of the function are recommended and in case of good conformity, the prognosis is recommended as the basis for forecasts given to Statkraft and as the basis for new power agreements with Vattenfall in combination with production forecast. For analysis of the trend for the voltage's RMS value, the deviation from the forecasted value is only a few tenths of a percentage. Here further studies are recommended and then specifically at area in the grid where installation of solar power is planned. The application PQ4Cast and the trend analysis function are expected to lead to economic benefits, such as reduced costs for purchase of electricity, reduced electricity grid charges and significant savings if disturbances that may lead to interruptions can be detected and prevented. Disturbances of short duration, such as voltage dips, are however hard to detect with the current setup of the application.
694

Towards Effective and Efficient Business Model change : Opportunities and challenges for software-intensive product development companies

Wilson, Magnus January 2019 (has links)
Digitalization initiates and drives significant changes to the process level, organization level, and business level of software-intensive product development (SIPD) companies and their customers. Digitalization creates new opportunities through digital transformation strategies of the business environment. Digitalization also significantly reduces the turnaround-time on a transaction, driving new challenges for the alignment of business and technology changes. For a successful business model realization, a company must understand what capabilities the organization has (in staff and products), what is required, and more importantly, how to turn these capabilities into good-enough abilities without disturbing the effectiveness and efficiency of the daily operations. Integrating the product and service development and the value delivery with a learning organization is critical for efficient business model change (BMCh). This thesis seeks to develop conceptual models for how BMCh is linked to value, learning organization design, and the transformation of capabilities into abilities derived from business model activities and actor interactions. Such conceptual models facilitate to investigate and identify critical mechanisms and capabilities needed to effectively and efficiently manage BMCh at full scale for SIPD companies, allowing them to exploit the on-going digitalization, may it be through (disruptive) business model innovation, technology innovation, or by continuously adapting and evolving the business operations.   I use the SIPD company as the unit of analysis, with the dual-lens of value and knowledge, set in the context of a business model and how the value creation and capture are influenced by the interaction between two actors performing a business model activity. I build on the business model literature and infuse theories for knowledge creation, learning organizations, and contractual promises to create value. Conducting a cross-disciplinary literature review, followed by a synthesis of related literature, industry best-practices, and an associated design science study, my propositions were validated in a longitudinal case study exploring a service industrialization program in the telecommunication industry. I have produced five conceptual models and seven propositions as a start to be able to support the design of a governance mechanism, as the critical engine for both the learning organization and effective and efficient BMCh. The industry now explores the models found during the case study. My synthesis shows a need for further research into BMCh regarding early detection and measurements of gaps in value, gaps in knowledge, ambiguity, equivocality, and abilities. Flexible role-based governance views present the measurements, as part of the governance mechanisms for full-scale, effective, and efficient BMCh. Further, I also aim to implement such governance mechanisms in software, by using the associated research in intent-driven systems. In the meantime, I propose industry to build knowledge and experience related to the seven propositions.
695

High Accuracy Speed and Angular Position Detection by Dual Sensor

Östling, Johan January 2018 (has links)
For many decades there has been a need in many industries to measure speed and position of ferrous gears. This is commonly done by converting passing gear teeth from trigger wheels to electrical impulses to calculate speed and angular position. By using Hall effect sensors or Giant Magnetoresistance sensors (GMR), a zero speed detection of gear teeth is possible while at the same time be cheap to produce and durable for harsh environments. A specially designed trigger-wheel (cogwheel created for measurements) with gear teeth in a specific pattern, exact position can be detected by using a dual sensor, even when no earlier information is available. The new design of trigger-wheel also makes this new method more accurate and universal compared to previous solutions. This thesis demonstrates and argues for the advantages of using a dual sensor for speed and angular position detection on gear wheels. Were one sensor do quantitative measurements for pattern detection in the teeth arrangements and the other sensor do qualitative measurements for position detection.
696

The Optimization of Solar Energy Harvesting in WSN

Li, Zhitan January 2018 (has links)
In recent year, wireless sensor networks have gradually become an indispensable part of people's daily lives. Energy consumption and energy harvesting play an important role in these systems. In outdoor, there is no doubt that solar energy is more suitable to powering the wireless sensor nodes. Although the energy consumption of these systems has been greatly reduced and the lifetime of sensor nodes also be improved through the larger capacity of supercapacitor or larger size of solar panel. But it will generate another kind of squander, how to choose a suitable solar panel and supercapacitor is appearance in our view. In this paper, I optimized the solar energy harvesting system from two aspects of capacity of supercapacitor and size of solar panel. The objective of this thesis has shown that as small solar panel and supercapacitor as possible for a given load of these systems under low consumption condition. Here, I establish the simulation in Simulink of Matlab, and build a low-power consumption; high-security solar energy harvesting hardware system for monitoring environment in Sundsvall, Sweden. Through the comparison between the simulation and real monitor to verify the feasibility
697

En bogvisirmodell : Underlag för ett PLC styrt bogvisir / A bow visor model : design material for a PLC-controlled bow visor

Turhede, Felix, Suskin, Vladimir January 2018 (has links)
Syftet med den här studien har varit att presentera ett underlag till konstruktion av en bogvisirmodell som skall kunna gå att styras med en PLC-enhet och som kan användas i undervisningssyfte för PLC-programmering. Underlaget förankrades i verkligheten genom en fältstudie och en litteraturstudie. Fältstudien inspirerade utformandet av bogvisirmodellen och bidrog med värdefull insikt i hur bogvisir fungerar. Litteraturstudien har bestått av två delar där en del har fokuserat på att undersöka regelverk som berör konstruktion av bogvisir och den andra delen har studerat hur två katastrofer, som involverade bogöppningar, har påverkat reglerna som rör bogvisir i SOLAS-konventionen. Litteraturstudien resulterade i två sammanställningar. En sammanställning av de regler ifrån SOLAS-konventionen, Transportstyrelsen och DNV-GL som reglerar konstruktion av bogvisir och en sammanställning av hur två katastrofer som involverar bogöppningar har påverkat reglerna i SOLAS-konventionen. Materialet ifrån fältstudien och litteraturstudien har använts till att utveckla ett underlag för hur en bogvisirmodell som styrs av en PLC-enhet, och som skall gå att använda i undervisningssyfte, kan konstrueras. / The purpose of this paper is to present design material that can be used to build a bow visor model which is controlled by a PLC unit and can be utilized as a tool when educating students in PLC programming. A field study and a literature study have been conducted to make the bow visor model realistic. The field study has inspired the design of the bow visor model and contributed valuable insight into the workings of a bow visor. The literature study consists of two parts where one part focused on studying regulations that regulates the design of a bow visor and the other part focused on studying how two disasters that involve bow doors have impacted the regulation in the SOLAS Convention. The literature study resulted in two compilations. One compilation consists of regulations from the SOLAS Convention, the Swedish Transportation Agency and DNV-GL regulating the design of bow visors and the other compilation consists of changes in the SOLAS Conventions regulations that are a direct result of two disasters that involve bow doors. The result of the field study and the literature study have been used to develop the design material for how a bow visor model, that is controlled by a PLC unit and can be used for educational purposes, can be built.
698

Smarta parkeringsplatser : MultiTech mDot-baserade parkeringsplatser utan extern strömförsörjning

Svensson, Oskar January 2017 (has links)
Internet of Things är ett begrepp som innebär att alla tänkbara enheter kan kommunicera med varandra. Utvecklingen är snabb och antalet uppkopplade enheter ökar enormt. Detta medför bland annat att samhället blir effektivare vilket innebär både ekonomiska och miljömässiga fördelar. Genom att göra parkeringsplatser smarta kan de lediga platserna snabbare lokaliseras vilket minskar både miljöpåverkan och bränslekostnad. Eftersom strömförsörjning kan vara ett problem vid en del parkeringsplatser undersöks huruvida det är möjligt att åstadkomma smarta parkeringsplatser baserat på en enhet utan extern strömförsörjning. Undersökningen görs genom att konstruera en prototyp och på den utvärdera ström- och effektförbrukning samt batteritid. Dessutom analyseras om en annan design på prototypen skulle prestera bättre genom att uppskatta strömförbrukningen för en sådan design och därefter beräkna effektförbrukning och batteritid. Prototypens konstruktion bestod av en ultraljudsgivare inklusive styrenhet, en mikrokontroller kallad mDot, ett 9 V-batteri och en strömbrytare. Med mDot:en kunde data sändas till en server via LoRaWAN. De utförda mätningarna och beräkningarna visade att prototypen drar mycket ström. En enhet med tillräcklig prestanda är dock möjlig att konstruera genom att utföra beräkningar i mDot:en istället för i ultraljudsgivarens styrenhet. Detta skulle minska strömförbrukningen vilket förlänger batteritiden. Uppskattningar visade även att batteritiden för en sådan enhet ökar exponentiellt mot tiden i viloläge. Slutsatsen är att batteritiden varierar beroende på hur enheten är designad samt hur länge enheten är i viloläge. Det är dock möjligt att konstruera en enhet utan extern strömförsörjning som har tillräckligt bra prestanda för att åstadkomma smarta parkeringsplatser. / Internet of Things is a term for describing that every imaginable device can communicate with each other. The development in the field is fast and the amount of connected devices increases at an enormous rate. This means that the society becomes more efficient and some part of this is economic as well as environmental benefits. By making parking lots smart, the vacant lots can be located more quickly thus reducing environmental impact and fuel cost. At some parking lots there is no power supply. This report investigates whether or not it is possible to achieve smart parking lots based on a device without external power supply. The investigation is done by constructing a prototype and evaluate its current and power consumption as well as its battery life. Furthermore, an investigation is done to find out if another design can perform better than the prototype. This is done by making assumptions of how another design might look and from that estimate its current consumption and then calculating power consumption and battery life. The prototype constructed existed of an ultrasonic sensor including control unit, a microcontroller called mDot, a 9 V battery and a power switch. The mDot was able to send data to a server via LoRaWAN. The performed measurements and calculations showed that the prototype used to much current. However, a device with sufficient performance is possible to construct by doing the computation in the mDot instead of in the ultrasonic sensors control unit. This would increase the battery life of the device. Estimations showed that the battery life of such a device increases exponentially to the sleep time. The conclusion is that the battery life will vary depending on the design and the sleep time of the device. It is however possible to design a device without external power supply that has sufficiently good performance to enable smart parking lots.
699

Audio classification with Neural Networks for IoT implementation

Khadoor, Nadim Kvernes January 2019 (has links)
This project is based upon two previous projects handed to the author by the Norwegian University of Science and Technology in co-operation with Disruptive Technologies.   The report discusses sound sensing and Neural Networks, and their application in IoT. The goal was to determine what type of Neural Networks or classification methods was most suited for audio classification. This was done by applying various classification methods and Neural Networks on a data set consisting of 8732 sound samples. These methods where logistic regression, Feed-Forward Neural Network, Convolutional Neural Network, Gated Recurrent Unit, and Long Short-term Memory network. To compare the Neural Networks the accuracy of the training data set and the validation data set were evaluated. Out of these methods the feed-forward network yielded the highest validation accuracy and is the preferable classification method. However, with more work and refinement the Long Short-term memory may prove to be the better solution.   Future work with a Vesper V1010 piezoelectric microphone and IoT implementation is discussed, as well as the social and ethical difficulties proposed by what is essentially a data gathering system.
700

WiFi Extension for Drought Early-Warning Detection System Components

Pukhanov, Alexander January 2015 (has links)
Excessive droughts on the African continent have caused the Swedish Meteorological and Hydrological Institute to launch a program of gathering data in hopes of producing models for rainfalls and droughts. A sensor capable of gathering such data has already been chosen, however there remains the problem of conveniently retrieving data from each of the sensors spread over a large area of land. To accomplish this goal, a small, cheap and efficient wireless capable module would need to be used. A possible candidate is the new WiFi-module from Espress if designated ESP8266. It is an extremely cheap and versatile wireless SoC that is able to perform the task of a wireless communications adapter for the sensor unit. The point of this thesis is to investigate the suitability of IEEE 802.11 for the task, and produce a piece of firmware for the ESP8266. The firmware shall enable it to be attached to a sensor and operate as a wireless mesh node in a self-organizing WLAN sensor network, enabling data retrieval via WiFi multi-hop deliveries.

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