Detta examensarbete har utförts på uppdrag utav Göteborg Energi Nät AB. Arbetet har en beskrivande del som handlar om hur det går till när nya kunder ansluts till det befintliga nätet och den andra delen av arbetet är en kartläggning över effektförbrukningen för kundkategorierna flerbostadshus, skolor och förskolor. När en kund vill ansluta en fastighet till elnätet begärs en effekt som av nätbolaget ofta uppfattas som högre än vad som egentligen behövs. Om detta är fallet borde servisledningarna vara lågt belastade och inte optimalt dimensionerade utifrån ett nätbolags perspektiv. Det finns inget underlag som visar på vilken belastningsnivå ledningarna har vilket gör det svårt att föra en dialog med kunden eller installatören gällande begärd effekt. Nätbolaget vill inte ta ansvar för att dimensionera kundens anläggning vilket är installatörens uppgift. Syftet med examensarbetet är att undersöka om det av kunden begärda effektuttaget i föranmälan är högre eller lägre än den faktiska maxförbrukningen. I rapporten undersöks vilken belastningsnivå servisledningarna har och utifrån det bedöms om ledningarna är över- eller underdimensionerade. Genom att ta fram mätvärden för utvalda anslutningspunkter kunde det verkliga effektuttaget jämföras med begärd effekt och därefter beräknades belastningsgraden på ledningarna. Vidare analyserades sambandet mellan olika kabelareor och deras belastningsintervall utifrån framtagna mätvärden. I denna rapport har anslutningspunkter för 87 flerbostadshus, 7 skolor, 18 förskolor och 3 skola och förskola under samma anslutningspunkt undersökts. Resultatet av studien visar att belastningsraden för de flesta ledningar anslutna till flerbostadshus var 25-34 procent och för skolor samt förskolor var den procentuella belastningen för de flesta ledningarna mellan 20- 29 procent vilket styrker hypotesen om att servisledningarna överdimensioneras. Ett steg i arbetet för att minska överdimensioneringen av ledningarna är att försöka förmedla till kunden eller installatören att belastningarna kan sammanlagras, eftersom kunderna inte kommer att ta ut maxeffekt samtidigt. / This bachelor’s thesis has been carried out on behalf of Göteborg Energi Nät AB. The work has a descriptive first part about how new customers are connected to the existing electric grid and the main part of the essay is a survey about power consumption for the customer categories apartment buildings, schools and pre-schools. When customers want to connect a property to the electricity grid, they often request an electric output that the network company perceive to be higher than necessary/what is required. If this is the case, the supply service line connection should have lower load and not be optimally dimensioned from a network company’s perspective. There is no data available that shows what level of load the supply service line connection have, which makes it difficult to start a dialogue with the customer or the electrician regarding requested power. The network companies do not want to take the responsibility to dimension the customer’s facility. The responsibility for this lies with an electrician. The purpose of the thesis is to investigate whether the power demand requested by the customer in advance is higher or lower than the actual maximum consumption. The report examines the level of load that the supply service line connection have and based on that information it gives an estimation of whether the supply service line connection are over or under dimensioned. By obtaining measured values from selected connection points and comparing the actual power consumption with the requested power, calculations can show the load rate of the supply service line connection. In this report, connection points were investigated on 87 apartment buildings, 7 schools, 18 pre-schools and 3 units with school and pre-school under the same connection point. The result of the study shows that the load rates for most electric supply service line connections. For apartment buildings the load rates were 25-34 percent and for schools and pre-schools 20-29 percent. This strengthens the hypothesis that the supply service line connections are over dimensioned. One step in the effort to reduce over dimensioning of the supply service line connections is to try to have a dialogue with the customers or electricians. It is then important to explain that the load can be aggregated and that all loads will not consume maximum power at the same time.

Försäljning av laddbara elfordon växer årligen vilket ger ett ökat behov av laddstationer på boendeparkeringar. Rapporten undersöker tekniska och ekonomiska förutsättningar för elbilsladdning på parkering till flerbostadshus åt Stenungsundshem. Av de typer elbilar som finns är det laddhybrider och rena elbilar som laddas med energi från elnätet. Den vanligaste typen på marknaden är laddhybriden som kan drivas både av en elmotor och en förbränningsmotor medan den rena elbilen endast drivs av en elmotor. Tiden för laddning av en elbil beror på om stationen är utformad med normalladdning, semisnabbladdning eller snabbladdning. För hemmaladdning är det vanligast med normalladdning där elbilen blir fullt uppladdad efter sex till tio timmar, batteriets storlek påverkar också tiden för laddning. Inkoppling till en laddstation kan ske med olika typer av kontakter, inom Europa är Typ 2 standard. Säkerheten vid laddning är viktig varför laddstaioner har delats upp i fyra olika säkerhetsklasser beroende på kommunikationsmöjligheter mellan laddstation och fordon, Mode 3 är standard i Norden. Laddning av elbilar kan resultera i höga effekttoppar vilket huvudsäkringen måste vara dimensionerad för. Dessa effekttoppar kan kapas om någon form av lastbalansering används som fördelar den tillgängliga effekten under dygnet mellan laddstationer så att nätet inte blir överbelastat. De som erbjuder elbilsladdning måste följa Ellagen i form av hur debitering får ske och hur laddstationer ska installeras. Detta förtydligas med hjälp av standarder och förordningar. Dimensionering gällande kabelarea och effektbehov vid olika antal laddstationer har utförts i detta projekt, aluminium kabel med PEX-isolering har använts uteslutande i detta projekt. Det har utförts en marknadsöversikt för att titta på olika lösningar och kostnader för kabelförläggning samt laddstationer. Det i nuläget bästa alternativet för Stenungsundhem anses vara att installera två stycken laddstationer för laddning av fyra boendeparkeringar. Med bidrag i form av initiativet ”Klimatklivet” kan investeringskostnaderna för laddstationer och kabelförläggning reduceras upp till 50%. / Sales of electric vehicles grow annually which increases the need for charging stations on parking lots at apartment houses. This report explore both the technical and the economical aspects of electric car charging for Stenungsundshem. The types of electric cars available on the market that can be charged by energy from the electric power network is the Plug-in hybrid and the electric car. The most common type on the market is the Plug-in hybrid which is driven by an electric motor and an internal combustion engine. The electric car is only driven by an electric motor. Charging times for electric cars depend on if the charging station is designed with normal charging or fast charging. For home charging, normal charging is the most common type of charging where the car is fully charged after six to ten hours. The connection between charging stations and cars can be made by different types of connectors. The European standard is the Type 2 connector. Safety is very important when charging electric cars, Therefore, charging stations have been divided into four different safety modes. Safety modes differ depending on the type of communication available between the charging station and the car. Mode 3 is the standardized mode in the Nordic countries. Charging of electric cars can result in power peaks which the main fuse must be dimensioned for. Power peaks can be reduced by using some type of load balancing system where available power during the day is distributed between charging stations to keep the power consumption below rated power. Terms of how charging is done and installation of charging station must be in compliance with Ellagen. For easier compliance and clarification of Ellagen standards and regulations should be used. In this project cable dimensioning by power requirements for different amounts of charging stations has been made, PEX insulated aluminum cable is exclusively used within the project. The market of charging stations is explored to look at different solutions and costs for charging stations and routing of cables. The best option for Stenungsundshem is currently to install two charging station for charging outlets to four parking spaces. Contributions like “Klimatklivet” can reduce total costs of investments for charging stations and cable routing with up to 50%.

Modern day vehicles is full of electronics, different sensors and software. To test that all these different systems works as expected it is suitable to build test beds. These test beds consists of, as far as possible, real components that should be implemented in the vehicles. A vehicle has various temperature sensors. Something that is important totest is how the vehicles systems reacts to different temperatures. This thesis aim is to construct a unit that can simulate a temperature sensor of type PT100. The unit should be able to be controlled via CAN and it should also be able to simulate short cicruit and open load. Digital potentiometers in parallel was used to simulate the temperature sensor. Relays was used to simulate short circuit and open load. The unit was calibrated and tested witha multimeter. When the multimeter was used the unit produced satisfactory results. When the unit was tested against the test bed it showed different values than with the multimeter thus further work is requierd. This thesis was conducted at BAE Systems Hägglunds AB in Örnsköldsvik.

The purpose with this pre-study of an underground railway track with d.c. traction was to examine alternatives to the auxiliary power, traction power and tracks/ return circuits. This with the problem of stray currents in mind as well with technical, safety and economy. The method used was primarily a literature study of theoretical, standards, other scientific studies, and calculations. The results and conclusions suggested to use a 1kV system for the auxiliary power system, a contact rail for the traction voltage and a slab track for rail and return circuit. This to keep drop voltage within limits, to keep system height down and limit the risk for stray currents. Furthermore, contact rail and slab track raise the comfort and safety, as well as lower the maintenance. The thesis stresses the importance of prevention of stray currents in initial stages of the planning and the fact that there are many ways to do this.

Delivering a fault-free software to the client requires exhaustive testing, which in today's ever-growing software systems, can be expensive and often impossible. Software fault prediction aims to improve software quality while reducing the testing effort by identifying fault-prone modules in the early stages of development process. However, software fault prediction activities are yet to be implemented in the daily work routine of practitioners as a result of a lack of automation of this process. This thesis presents an Eclipse plug-in as a fault prediction automation tool that can predict fault-prone modules using two prediction methods, Naive Bayes and Logistic Regression, while also reflecting on the performance of these prediction methods compared to each other. Evaluating the prediction methods on open source projects concluded that Logistic Regression performed better than Naive Bayes.As part of the prediction process, this thesis also reflects on the easiest metrics to automatically gather for fault prediction concluding that LOC, McCabe Complexity and CK suite metrics are the easiest to automatically gather.

In recent years, the number of photovoltaic systems (PV systems) has increased in Sweden. According to the Swedish Energy Agency the number is expected to continue to increase in the future, much thanks to the declining prices of PV systems. The government´s goal of 100% renewable electricity generation in 2040 can be achieved if half of all small houses in Sweden install PV systems.The 31st of December 2017, Gävle Energi had 39 PV systems whereof 16 had installed capacity of less than 5kW, corresponding to 0,16% of the Swedish PV installations of less than 5kW. In this report a study of how the voltage quality is affected by installation of an increased number of single phase PV systems is presented. The study is performed on 4 different rural area distribution grids and the voltage is analysed with respect to the following quality criteria’s: • Voltage change in connection point, max 5% • Voltage change in interconnection point, max 3% • Voltage variation, ±10% of nominal value (207-253V) 2 different scenarios have been considered for each area: • ”The two houses with largest impedances have PV systems” • ”50% of the houses in one area have PV systems” The simulations performed in this study show that the voltage exceeds one or more of the electrical quality requirements listed above for all four of the studied areas. Measures such as cable reinforcement in connection points and/or interconnection points is recommended.

Many consumer products, such as within the computer areas, computer graphics, digital signal processing, communication systems, robotics, navigation, astrophysics, fluid physics, etc. are searching for high computational performance as a consequence of increasingly more advanced algorithms in these applications. Until recently the down scaling of the hardware technology has been able to fulfill these higher demands from the more advanced algorithms with higher clock rates on the chips. This that the development of hardware technology performance has stagnated has moved the interest more over to implementation of algorithms in hardware. Especially within wireless communication the desire for higher transmission rates has increased the interest for algorithm implementation methodologies. The scope of this thesis is mainly on the developed methodology of parabolic synthesis. The parabolic synthesis methodology is a methodology for implementing approximations of unary functions in hardware. The methodology is described with the criteria's that have to be fulfilled to perform an approximation on a unary function. The hardware architecture of the methodology is described and to this a special hardware that performs the squaring operation. The outcome of the presented research is a novel methodology for implementing approximations of unary functions such as trigonometric functions, logarithmic functions, as well as square root and division functions etc. The architecture of the processing part automatically gives a high degree of parallelism. The methodology is founded on operations that are simple to implement in hardware such as addition, shifts, multiplication, contributes to that the implementation in hardware is simple to perform. The hardware architecture is characterized by a high degree of parallelism that gives a short critical path and fast computation. The structure of the methodology will also assure an area efficient hardware implementation.

Renova hade behov av att utföra en energikartläggning på avfallskraftvärmeverket i Sävenäs. Syftet med detta examensarbete var att hjälpa till i den fullständiga energikartläggningen och komma med förslag på elenergibesparing. Under examensarbetet studerades endast elenergi. Energimätningarna utfördes med två instrument från Chauvin Arnoux. Instrumenten som användes heter CA 8335 och CA PEL103. Objekt som mättes i anläggningen var värmare och motorer som driver fläktar och pumpar. De delar av anläggningen som mättes upp under examensarbetets tid var Panna 5 och de gemensamma laster som används för samtliga förbränningspannor. Anläggningens driftförhållanden varierar sällan och därför beslutades att göra dygnsmätningar. Projektledaren bestämde att minst 80 procent av varje ställverks aktiva effekt skulle mätas upp för att få en godkänd nivå i energikartläggningen. Metoden för mätningarna var att starta på den största effektförbrukaren och arbeta sig ner mot den minsta effektförbrukaren. Mätningarna pågick i samma ställverk tills minst 80 procent av ställverkets aktiva effekt var uppmätt. Därefter fortsatte mätningarna i ett nytt ställverk. Parallellt med mätprocessen pågick analys av mätdata för att hitta möjliga förslag på elenergibesparing. Under det här examensarbetet mättes 2576,6 kW utav 9500 kW upp, detta motsvarade 27,1 procent av hela anläggningens elenergiförbrukning. Utav den uppmätta medeleffekten gick 1097,5 kW till pumpar, 957,7 kW till fläktar, 90 kW till värmare och 431,4 kW till övrigt. En energibesparing för MFL537-05 redovisas i form av ett förändrat driftmönster med hjälp av en frekvensomriktare. Objektet valdes eftersom fläkten inte drevs på ett effektivt sätt. Förändringen i driftmönstret skulle bespara cirka 50 MWh/år och 18 000 kr/år. Detta motsvarar 0,07 procent av anläggningens totala energiförbrukning på 74 200 MWh/år. / Renova had to perform an energy audit on their waste-to-energy plant at Sävenäs. The purpose of this thesis was to assist in the full energy audit and come up with proposals on how to make electric energy savings. Only electric energy was studied during this thesis. Energy measurements were performed with two instruments from Chauvin Arnoux. Instruments used are called CA 8335 and CA PEL103. Objects that were measured in the plant were heaters as well as fans and pumps driven by motors. The parts of the plant that were measured during the work was Boiler 5 and the common loads that are used for all boilers. The plant’s operating conditions rarely change and therefore it was decided to make daily measurements. The project manager decided that at least 80 percent of each switchgears active power should be measured to get an acceptable level in the energy audit. The method used during the measurements was to start on the largest power consumer and then work down to the smallest power consumer. The measurements took place in the same switchgear until 80 percent of the switchgears active power was measured. Afterwards the measurements continued in a new switchgear. Previous data were analyzed while the new measurements went on. The analysis was made in order to find possible proposals on how to make electrical energy savings. During this work 2576.6 kW were measured out of totally 9500 kW. This measured power corresponds to 27.1 percent of the plant’s total electric energy consumption. 1097.5 kW was consumed by pumps, 957.7 kW was consumed by fans, 90 kW was consumed by heaters and 431.4 kW was consumed by other objects not included in any of the previously mentioned categories. One proposal was presented for object MFL537-05. The proposal was to use an frequency converter to change the objects operating pattern. The change in the objects operating pattern would save approximately 50 MWh/year and 18 000 SEK/year, which equals 0.07 percent of the plants total energy consumption. The plants total energy consumption is 74 200 MWh/year.

No description available.

Size measurement of iron ore pellets in industry is usually performed by manual sampling and sieving techniques. The manual sampling is performed infrequently and is inconsistent, invasive and time-consuming. Iron ore pellet's sizes are critical to the efficiency of the blast furnace process in the production of steel. Overly coarse pellets affect the blast furnace process negatively, however this affect can be minimized by operating the furnace with different parameters. An on-line system for measurement of pellet sizes would improve productivity through fast feedback and efficient control of the blast furnace. Also, fast feedback of pellet sizes would improve pellet quality in pellet production. Image analysis techniques promise a quick, inexpensive, consistent and non-contact solution to determining the size distribution of a pellet pile. Such techniques capture information of the surface of the pellet pile which is then used to infer the pile size distribution. However, there are a number of sources of error relevant to surface analysis techniques. The objective of this thesis is to address and overcome aspects of these sources of error relevant to surface analysis techniques. The research problem is stated as: How can the pellet pile size distribution be estimated with surface analysis techniques using image analysis? This problem is addressed by dividing the problem into sub-problems. The focus of the presented work is to develop techniques to overcome, or minimize, two of these sources of error; overlapped particle error and profile error. Overlapped particle error describes the fact that many pellets on the surface of a pile are only partially visible and a large bias results if they are sized as if they were smaller entirely visible pellets. No other researchers make this determination. Profile error describes the fact that only one side of an entirely visible pellet can be seen making it difficult to estimate pellets size. Statistical classification methods are used to overcome these sources of error. The thesis is divided into two parts. The first part contains an introduction to the research area together with a summary of the contributions, and the second part is a collection of four papers describing the research. / <p>Godkänd; 2007; 20071018 (ysko)</p>