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  • 1.
    Akiki, Cesar
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Torstensson, Daniel
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Hur routingtabellens storlek påverkar paketets fördröjning i en router eller L3 switch2017Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The internet is growing, and more devices are becoming connected for each day that passes by. This will increase the number of routes in the routing-table on the routers and L3 switches and as they are increasing it will affect the delay on the packets traversing between the source and destination. Or does it matter? Does the size of a routing table affect the delay? In this study, we have researched if there is a difference in the delay on the packets in a comparison to the size of the routing-table and this is compared between a router and L3 switch. During this study, we have been using a desktop computer that has two network interfaces installed in it and is connected to a router or L3 switch. We used three different programs on the computer that have been very helpful for completion of our work: Wireshark, to monitor and capture packets and the time between the two network interfaces on the desktop computer. Tftpd32, to copy the running-configurations from the router or L3 switch over to the desktop computer and back. Ostinato, is used to generate and send out packets on the network. All the results we got from our tests point to that there is no increase in delay no matter how much the routing-table is increasing. These results challenge previous studies that tells us the opposite, that the increase of a routing-table does have an increase in delay.

  • 2.
    Albadri, Rand
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Jämförande analys av driftsäkerhet medRTU och PLC2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis will make a comparative analysis of the operation safety of the wire connection to Remote Terminal Unit (RTU) and Programmable Logic Controller (PLC) with bus-controller. The report describes the basic description of the difference between these two systems and will explore which is safer and more economic with consideration to qualification according to Swedish energy companies' guidelines for dam safety (Ridas).Through course literature, ABB Bok, internet web sits and interviews with Skellefteå Kraft AB staff the result of this report have been created.The report results prove that PLC with bus-controller will operate operationally safe and profitable compared to wire connection to RTU. Results also showed that there is nothing which prevents to install bus-controller according to RIDAS but certain features should be installed.

  • 3.
    Alizadeh Khameneh, Mohammad Amin
    et al.
    KTH.
    Eshagh, Mehdi
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Sjöberg, Lars E.
    KTH.
    Optimisation of Lilla Edet Landslide GPS Monitoring Network2015In: Journal of Geodetic Science, ISSN 2081-9919, E-ISSN 2081-9943, Vol. 5, no 1, p. 57-66Article in journal (Refereed)
    Abstract [en]

    Since the year 2000, some periodic investigations have been performed in the Lilla Edet region to monitor and possibly determine the landslide of the area with GPS measurements. The responsible consultant has conducted this project by setting up some stable stations for GPS receivers in the risky areas of Lilla Edet and measured the independent baselines amongst the stations according to their observation plan. Here, we optimise the existing surveying network and determine the optimal configuration of the observation plan based on different criteria.We aim to optimise the current network to become sensitive to detect 5 mm possible displacements in each net point. The network quality criteria of precision, reliability and cost are used as object functions to perform single-, bi- and multi-objective optimisation models. It has been shown in the results that the single-objective model of reliability, which is constrained to the precision, provides much higher precision than the defined criterion by preserving almost all of the observations. However, in this study, the multi-objective model can fulfil all the mentioned quality criteria of the network by 17% less measurements than the original observation plan, meaning 17%of saving time, cost and effort in the project.

  • 4.
    Alizadeh-Khameneh, Mohammad Amin
    et al.
    Division of Geodesy and Satellite Positioning, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Eshagh, Mehdi
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Sjöberg, Lars
    Division of Geodesy and Satellite Positioning, Royal Institute of Technology (KTH), Stockholm, Sweden.
    The Effect of Instrumental Precision on Optimisation of Displacement Monitoring Networks2016In: Acta Geodaetica et Geophysica Hungarica, ISSN 1217-8977, E-ISSN 1587-1037, Vol. 51, no 4, p. 761-772Article in journal (Refereed)
    Abstract [en]

    In order to detect the geo-hazards, different deformation monitoring networks are usually established. It is of importance to design an optimal monitoring network to fulfil the requested precision and reliability of the network. Generally, the same observation plan is considered during different time intervals (epochs of observation). Here, we investigate the case that instrumental improvements in sense of precision are used in two successive epochs. As a case study, we perform the optimisation procedure on a GPS monitoring network around the Lilla Edet village in the southwest of Sweden. The network was designed for studying possible displacements caused by landslides. The numerical results show that the optimisation procedure yields an observation plan with significantly fewer baselines in the latter epoch, which leads to saving time and cost in the project. The precision improvement in the second epoch is tested in several steps for the Lilla Edet network. For instance, assuming two times better observation precision in the second epoch decreases the number of baselines from 215 in the first epoch to 143 in the second one.

  • 5.
    Almahdawi, Shahad
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    The impact of using touch technology in elementary education2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Before the touch-sensitive screen technology invented and being widely used all over the world, the education process was limited to three main points, the student, the teacher and the subject. Now the touch-sensitive screen is quickly becoming the fourth point that supports the education process.

    The aim of this project is to define the role of touch technology on education, and to check how the process has changed using new materials. The project will mainly analyse the impact of those devices in primary schools, age 6 – 12 years and their teachers.

    The report is divided into three main parts, the first part is to examine the effect of touch devices on the student, the second part related to the impact of these devices on the teacher and the third part will investigate how the touch technology influences the educational material. In the report I will also try to highlight the most important pros and cons of this technology, and also to highlight the most important flaws and shortcomings of using the devices in this area to make use of this useful technology.

    The study will also show how the results differ using such devices, outcomes including doing homework, working together in groups, communicating with other students and teachers.

  • 6.
    Andersson, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Hägerström, Martin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Beredningsarbete på Galtö med undersökning av miljöaspekter vid ombyggnad av distributionsnät2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis deals with the practices of processing work. The work is being performed with TROLK El & Tele AB and is ordered by Ellevio AB. The area that the work is carried out at is Galtö in Tanum. The area includes about 10 km cable installation, 4 substations and 5 satellite substations and three low voltage areas where the grid are going to be rebuilt. Ellevio AB has invested in this project as they want to weather proof and ensure a high quality of the power delivery. The preparatory work that is presented as a proposal TROLK can continue to work with and apply for the relevant permits. These permits have been accounted for when this work has been prepared. The existing overhead line will be dismantled when the new grid has been connected. The overhead line is approximately 5.2 km long and includes nine pole mounted transformers. The work is based on the project documents that Ellevio has provided, though some changes have been made where necessary.

    The thesis also identifies the environmental aspects arising from the dismantling of an overhead power grid and investigates alternative solutions to reduce the environmental impact. When TROLK are working with projects commissioned by Ellevio they are using the environmental plan handed by Ellevio. The environmental plan have been studied and compared with other actors' environmental plans in order to identify potential improvements. The study identified that the greatest environmental aspects is the hazardous waste of creosote impregnated power poles and PCB-contaminated oil. No major improvements in the waste management has been. Focus has then been to examine options to replace the hazardous materials for new installations. It has been found several different options to the creosote power pole that all have different effects on the environment and there are therefore no obvious alternative. PCB-contaminated oil are currently not allowed in the grid but as it means a big expense to replace dispensations has been distributed to the owners of the power grid until it has been rebuilt.

  • 7.
    Andersson, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Leinonen, Markus
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Projektering och elkvalitetsstudie av laddstationer för elfordon2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the last couple of years, the evolution of plug-in electric cars has contributed to an increasing need of well-built charging infrastructure. This does not only require that the fair amount of charging stations needs to match the increasing demand, but the growing amount of charging station could also affect the power quality in the grid itself due to the technology used today.

    The objective of the first part of the project was to deliver a complete installation plan and project basis of two AC charging stations for electric vehicles, planned in the city of Kungälv. The second part of the project was focused on studying the effects of DC fast charging of electric vehicles, with power quality in mind. This study was based on readings obtained from measuring the power quality at an existing DC fast charging station in Kungälv, as well as available publications within the area of the subject. The project planning was conducted in regards to Swedish standards and regulations, as well as to the instructions and expectations of the client, Kungälv Energi. The result was compiled and handed over to the client during the final part of the project. The resulting document contained information regarding installation, material and placement as well as approximate cost calculations.

    The power quality study was carried out on a currently installed fast charging station located in the city of Kungälv, using power quality measuring instruments provided by Kungälv Energi and Metrum Sweden AB. The result was a power quality report, compiled according to Swedish Energy Markets Inspectorate, where all requirements concerning power quality were met. The data was also analyzed manually, to further investigate the effects of DC fast charging. The study shows no immediate signs of negative impact of the power quality in the nearby grid caused by the fast charging stations within the project. There were signs of harmonics caused by the charging stations, but the presence was considered low. The usage frequency is however a major factor when investigating the power quality affection of the charging station. This results in a conclusion that is not generally applicable.

  • 8.
    Andersson, Christoffer
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Andersson, Pontus
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Beredning av distributionsnät Myren-Torseröd i Tanum2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report will focused on how the preparatory work between Myren-Torseröd in Tanum will proceed. On behalf of Ellevio AB, the preparation and construction company Trolk EL & Tele AB shall weatherproof an area between Galtö-Torseröd in Tanum. This report will only include the distribution 0,4-24 kV in the area between Myren-Torseröd. The existing overhead line network will be dismantled and replaced with underground cables. Even existing substations and pole stations to be scrapped and replaced with new ones. During the preparatory work, there have been field visits to get an overview of the field of processing operations, and to measure the position of e.g. substations. To have access to the ground the preparation worker must sign contracts with landowners, and shall also seek authorization from the County Administrative Board, the transport department and municipality. The entire preparation work in this project includes 68 customers.

  • 9.
    Andersson, Hannes
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Udéhn, Robin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Switchover med NSF och SSO: en jämförelse med HSRP2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna B-uppsats har vi valt att jämföra olika sätt att skapa redundans i ett nätverk. Valet av redundansmetoder tog vi det nyare Non-stop Forwarding (NSF) med Stateful Switchover (SSO) en metod vi inte hittat några exakta siffror på hur snabbt det är och jämförde med det äldre mer välkända protokollet Hot Standby Routing Protocol (HSRP). Vi använde oss av Catalyst 6500 switchar som enheter för att göra mätningarna och tiden det tog för NSF med SSO att slå över från passiv till aktiv modul medan HSRP räknades på tiden det tog att slå över från en passiv till aktiv enhet vid länkbrott. Detta gjordes för att vid länkbrott anses det aktiva modulkortet fortfarande vara användbar och trafik skickades via den passiva modulen till den aktiva vilket inte gav oss någon switchover. Våran slutsats är att NSF med SSO är den bättre metoden och den har överslagstider närmare 0.5 sekund men att HSRP kan mäta sig med det om man pressar ner protokollets timers tillräckligt, dock inte utan ett pris. Nedpressnignen av timers kommer leda till att enheterna överbelastas till skillnad från om NSF med SSO används.

  • 10.
    Andersson, Helen
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Analys av ett distributionsnät i en bangård2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An analysis of an electrical distribution system located in a railway yard have been requested by Atkins Global AB. The system includes electrical distribution to signal equipment, heating equipment for the switches and lightning for the platforms.

    The initial part of the analysis consisted of a literature study regarding requirements for this type of system and the gathering of data regarding the cables and the fuses in it. The cabling are either of the type FXQJ or AXQJ. The system is normally powered from a three-winding transformer via two centrals, the first central A1 supplies the signal equipment electricity, through the subcabinet F3, and the lightning both powered by a main voltage 400V and central B1 powers the equipment for heating the switches with the main voltage 230V. The distribution from B1 consists of two parallel cables feeding a subcabinet FS4/36.There also exists an auxiliary power supply from a smaller transformer T3, used if the main power supply should disappear.

    The remaining investigation was conducted in the calculation program MyEcodial by Schneider Electric. The investigation focused on personal safety and short current calculations. The result was a series of suggested changes regarding the fuses and cables in the system.

    The results of the investigation regarding the powering of the signal equipment was such that a recommendation to change the cable going from F3 to one of the signal cabinets to an AXQJ 3x95/29 cable and to conduct a current measurement regarding if the present 100A fuse can remain or if it should be switched to an 80A fuse. From F3 to both the main power supply and the auxiliary power supply new fuses with 200A must be put in to ensure that the cables are protected. For the powering of the lightning it was the selectivity between the fuses that was the problem since they both had the size 63A, the investigation proved that it was the lower fuse that should be replaced with a fuse with highest 50A and lowest 32A. Regarding the power supply for the heating of the switches it is once again necessary to do a current measurement to determ if it is possible to switch the present 400A fuse to a smaller one on 315A. If not then two more cables of the same size as the present ones must be installed parallel to the present ones to ensure safety for people.

  • 11.
    Andersson, Hugo
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Gannholm, Rebekka
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    En jämförelse mellan två generationer av GNSS-instrument2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study examines whether there is any difference in a new generation of Global Navigation Satellite System instruments (GNSS) in the accuracy of positioning and whether there is any time difference when using the different instruments. The study compares the instruments used today by Lantmäteriet, the Leica Viva CS15 and the GS15, with the Trimble GeoExplorer 6000 XR. The GeoExplorer can be used either with an integrated or an external antenna to receive satellite signals, both configurations are investigated in this study. The study was carried out by establishing two core networks with set measurements, to obtain "true" coordinates to compare against the measurements made with the GNSS-instruments. The networks were transformed into SWEREF 99 12 00 using static GNSS surveying. Then each point was measured 30 times by each of the GNSS instruments, in order to get statistically reliable data. The result shows that Trimble with an external antenna generally had the best precision (0,009-0,020 meters in the shrouded network and 0,008-0,013 meters in the open network) but had less accuracy (0,016-0,088 meters in the shrouded network and 0,032-0,054 meters in the open network), in other words a greater distance from the "true" coordinate. The Leica instrument had a lower precision (0,021-0,142 meters in the shrouded network and 0,014-0,032 meters in the open network), but better accuracy (0,006-0,076 meters in the shrouded network and 0,019-0,059 meters in the open network). Trimble with the internal antenna had the lowest precision (0,021-0,038 meters in the shrouded network and 0,013-0,048 meters in the open network) and accuracy (0,026-0,083 meters in the shrouded network and 0,024-0,068 meters in the open network). A time course study was also conducted by measuring the time it took from the point where the instrument was turned on, to when the initialization was completed. The result of the time study was that the Leica Viva was about 12 percent faster when the environment was free of obstacles, and around 21 percent faster when the immediate area was more forest like with trees and bushes. The conclusion of the project is that the instruments are equivalent in terms of quality of measurements and time. The big difference is found in the weight and center of gravity of the instruments, where Trimble with internal antenna has the lowest weight.

  • 12.
    Andersson, Johnny
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Karlsson, Robin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Uppstartsguide för Febdok2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete har utförts på ÅF Industry i Trollhättan. Syftet med examensarbetet är att arbeta fram rutiner och ett standardiserat arbetssätt i Febdok. Detta för att underlätta och spara tid vid användning av Febdok. Inledningsvis påbörjades framtagning av relevant teori kring den definierade problembeskrivningen tillsammans med handläggaren på ÅF. Parallellt genomfördes övningsexempel i Febdok för att gruppen skulle få en insyn i hur funktionerna fungerar. Rapportens teoridel behandlar de mest problematiska- och tidskrävande funktionerna i Febdok så som UPS:er, kortslutningsströmmar och selektivitet. Det för att ge en förståelse om bakgrunden till funktionerna. Ett beräkningsexempel på ett fiktivt nät gjordes för att kunna verifiera en överslagsräkning som används på ÅF för att beräkna ett ungefärligt värde på minsta felström. Denna minsta felström erhålls vid enfasig jordslutning och definierar utlösningsvilkoret. Maximal felström delat på tre har ansetts ge ett någorlunda korrekt värde på minsta felström. Beräkningar på maximal- och minimal felström vid olika kablage jämfördes och visade att överslagsräkningen inte är att rekommendera på grund av att minsta felström ibland bli lägre. Istället bör en faktor av minst fyra användas vid överslagsräkningen för minsta felström. I avsnitt 3 i rapporten beskrivs initiala inställningar och funktioner i Febdok med föregående teori som bakgrund. Implementering av UPS:er i Febdok visade sig kräva mer datainmatning än vad som normalt går att få tag på från tillverkare. Genomsläppt energi är data som visade sig svår att få tag ifrån olika tillverkare. Vid närmare tester av programmet och dess funktioner visade det sig att genomsläppt energi inte behövs definieras i UPS-funktionen för att arbeta med selektivitet och kortslutningsströmmar längre ut i anläggningen.

    Resultatet av observationerna i Febdok och teorin visade att tumregeln som används på ÅF inte är att föredra och säkringar i en anläggning försedd med UPS bör dimensioneras efter batteridrift. Informationen och kunskaperna som samlades under arbetets gång samanställdes i en uppstartsguide för Febdok. 

  • 13.
    Andersson, Karin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Carmesund, Julia
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Handläggningstiden vid bygglov: En studie kring kravet i PBL 9:272015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With Swedish planning and building act (PBL) of 2011 a new demand was adopted for handling time before permits and advance rule, called PBL 9:27. Following PBL 9:27 an application for permits shall be processed promptly and the applicant shall be informed of the decision within ten weeks from the moment a complete application has been submitted to the local building committee. Previously this demand had not been included into Swedish law. The purpose of this demand was to speed up the handling time and to reduce differences in handling time between municipalities. When this demand was adopted a decision was made not to connect it with any form of sanction, should the demand not be met. The argument being that a more effective handling time would be met even without sanctions. Following several notifications to the legal ombudsman one may conclude that in several cases, municipalities do not meet the demand for a handling time within ten weeks. While there are no sanctions connected to the demand municipalities, may without any risk, take as much time they fell needed for the handling of each case. Thereby one of the key purposes of PBL 9:27, that is, reduced differences in handling time between municipalities is counteracted.

    The purpose of this study is to investigate whether handling time in building permit cases are in compliance with PBL 9:27. In order to answer this question building permit cases were examined thoroughly in seven municipalities in Västra Götaland County. The study has focused cases from 2014 and cases pertaining to construction of buildings. The collected information was compiled in one data matrix for each municipality. Beside of the information compiled in the data matrix each municipality answered a questionnaire focusing workload. The purpose of the questionnaire was to relate the results from the investigation of handling time to a possible explanation, that is, the workload of employees during 2014.

    Out of 436 examined cases 44 did not meet the demand of handling tie within ten weeks, or approximately 10 % of the cases. Of these 44 cases that did not meet PLB 9:27, 32 were real estates that were located within areas regulated by detailed municipal plans and twelve were located outside of planned areas. Out of the 32 real estates located within planned areas 13 accounted for a minor deviance from the detailed municipal plan while 19 were in compliance with the detailed plan and

    regulation areas.

    The results indicate that municipalities need to speed up their handling time for building permit cases regulated by PBL 9:27. An additional result of this study is that several municipalities have flaws in relation to documentation of significant dates. Also, municipalities tend to make different assessments of when an application is considered complete. This study suggests that clearer guidelines are adopted pertaining to documentation of cases and the demands for how to assess if an application is complete.

  • 14.
    Andersson, Linnea
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Hansson, Jenny
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    LOU:s tillämpning på PBL 6:402015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    By the beginning of 2015 a couple of new articles in the Swedish Planning and Building Act (PBL) were introduced. For the first time in history there are specific sections that regulate Swedish development agreements. The purpose is the political will to create a faster and simpler planning process. Among other things it is about creating transparency and an openness in the procedure so that a constructor can calculate in advance their costs for a certain project. At the same time it is also about giving the municipality and its residents awareness of the consequences of the agreement. The purpose of this study is to straighten out how to interpret the notion "to institute" in PBL 6:40. The method used was both quantitative with a conducted survey and qualitative with interviews. The survey was sent to all 290 municipalities in Sweden and got a responserate of 57 %. Interviews were made with four persons in the trade and seven municipalities.

    The results show that a majority of the Swedish municipalities construct public areas with municipal mandatorship, when the municipality does not own the land, with a public procurement according to the Swedish Act on Public Contracts (LOU). A couple of the municipalities admit that they make exceptions for contracts with minor monetary values. At the end of the day the civil servants of the municipalities are dubious about changing their work procedures, to one where the developer is allowed to construct, because the legal position is uncertain. The results also clearly show that there is, in general, a great insecurity and confusion about the notion "to institute" and its interpretation among both civil servants and persons in the trade. It appears that a public procurement should always be used when the trigger value is transcended or when there is a cross-border interest. In other cases the legal position is unclear and it seems that PBL 6:40 and LOU collide, even though these legalisations should exist in harmony. For that reason a clarification about how the interpretation should be done is needed in the law.

  • 15.
    Andersson, Martin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Hägerström, Martin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Sammanställning av utbildningsmaterial om reservkraft med inriktning dieselaggregat2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today's society is composed of a constant energy dependency to get all functions of the modern society to function, a power failure can be devastating. Even though Sweden has a strong power grid, the requirement to always have access to electricity has opened up a market for back-up power. The aim of this work was to create material that could be used in educational purpose and for the reader to get a basic understanding of back-up power with focus on diesel generated power. The course material consists of recommendation of content in the form of page references from sources that fit well in the compilation ofeducation material in the form of a compendium. The compendium is supplemented with a layout of a PowerPoint presentation that can be used for educational purposes. By studying the relevant sources, we have deepened in our topic diesel generated power and have picked out page references, in accordance with the agreement regarding the school copy law, which we consider to be a good fit for the creation of a compendium. We have also created a foundation to a PowerPoint that can facilitate the creation of lecture material. This report explains the structure of a diesel power generator and what is important to consider when sizing a power system. The report also discusses recommended maintenance as well as the requirements placed on a diesel power generator.

  • 16.
    Arkevall, Martin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lundgren, Simon
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Återställning av filer: jämförelse av tre gratisverktyg2017Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    To try find a lost file which has been deleted by mistake is probably a common issue for many users. The fact that the recycle bin has been erased too makes the situation more complicated. Or even worse, if a whole partition was reformatted and overwritten. Most users are aware of available support either by contacting a data recovery company or by searching the internet for free tools. Because of the above mentioned common issues, the project has selected three recovery tools to test and compare to find out which tool performs best regarding recovery out of a selection of lost common files. The selection of tools were based from a list with mandatory requirements. The three tools that passed the list was Recuva, Lazesoft and Puran. The results showed variances between the tools where one tool was best in test to recover files back to its original. Another tool performed best when the original size increased after file recovery but the actual data still was functioning properly.

  • 17.
    Asp, Patrik
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Säkerhetsanalys av trådlöst nätverk2015Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study is to observe a corporate wireless network to find potential security holes. The goal of this is to make the network more secure and able to withstand attacks. The method is to interview the IT manager at the company to get a good overview of how their wireless network looks like. It's also applied a risk analysis to eventually use acombination of a risk analysis and interview to get results. The results show that the company has several security holes in their wireless network. Safety flaws that the company has is based on that a hacker must be on the inside of the network to take advantage of these security holes. Measures have been given to the company so that they can fix the security holes that have been found. But the company is keeping high standards overall.

  • 18.
    Augustsson, Angelica
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Albertsson, Cecilia
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lantmäterier i Norden: Dess centralorganisationer och det nordiska samarbetet2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study is to highlight similarities and differences between the different central organizations for surveying in the Nordic counties. The Nordic cooperation’s will be examined to gain a deeper understanding for the cooperation between the countries.

    Denmark’s organization is consisted by several boards. Those who perform cadastral proce-dure are private operators who report changes in property to the boards for registration. The organization is complex and difficult to get an overview of. The central organization of Finland is large and extensive, with multiple devices, areas and departments controlled by directors. The organization is owned by the state where both cadastral procedure and cadastre is within the central organizations responsibility. The central organization of Norway is owned by the state, with few work areas and specializations. They handle maps, cadastre and registration. It is Jordsifteretten who perform major ordinances and municipalities perform the minor. They are investigation whether the cadastral procedure should be private in order to develop and improve the surveying process in the country. Sweden like Finland has a central organization owned by the state who is handling cadastral procedure and cadastre. The organization is built in a number of different divisions that manage registration of property, cadastre and geodesy. In addition to the government offices are also municipal offices. In both the central organizations and in the countries different surveying associations are Nordic cooperation’s. Both seek to strengthen communion and enable exchange of expertise between the counties.

    The central organizations of Denmark, Finland, Norway and Sweden are different from each other, but there are still some similarities. The possibility to create an organization that works across the countries in common, is limited by national legislation. A unified central organization will therefore not be formed, nor is it the purpose of the Nordic cooperation’s. By mapping the central organizations an overview is created of the variations between the countries. But despite these differences succeed to get similar results in terms of surveying operations in the Nordic countries.

  • 19.
    Axelsson, Daniel
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Olsson, Daniel
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Utvärdering av olika dynamiska lastmodeller i PSS/E2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor’s thesis has been performed for Vattenfall Eldistribution AB. The purpose of this work has been to create understanding of dynamic load models and clarify how they function and how they can be used. The aim has been to perform simulations on short circuits and motor starts for two different load models. A part of the work is also to describe the basic principles of the induction motor to create a connection between simulation and theory. The theory of the induction motor contains information about the electric induction that is the basic principle of the induction machine. It also contains the correlations between torque, speed, current and voltage and also a description of the equivalent electric circuit. The IMD program is a program connected to PSS/E and it has been used to create the model for the induction motor that has been used for the simulations. The simulations have been based on instructions from the advisor and instructions from the PSS/E manuals. Simulations have been run with two of the built-in load models in PSS/E, one general load model and one model for induction motors. Short circuits have been simulated on both models and motor starts on the induction motor model. Short circuits have been simulated with two different fault durations 0.15 and 0.4 seconds. Motor starts have been simulated with two different transformer sizes 1.5 and 3.0 MVA and three different values of the inertia time constant 0.7, 1.0 and 1.5 MWs/MVA. At short circuit the fault duration causes larger currents and longer recovery times for both load models. At motor start the size of the transformer, in MVA, and the inertia time constant affects the motors starting time. Larger transformer means shorter time because of lesser drop in voltage. A larger inertia time constant means longer time.  If only the size of the voltage drop is of interest and not the course of the event, the motors start admittance can be used instead.

  • 20.
    Axelsson, Robin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Wangerås, Simon
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Övertagande av huvudmannaskap för allmän plats: En studie av kommuner som behandlat frågan kring övertagande av huvudmannaskap för allmän plats i detaljplan2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The study's 13 municipalities who want or have treated the matter of the choice of the mandatorship for the public space in new and existing detail plans. In Boverkets spaning - Huvudmannaskap innebär svårigheter, they mentioned several problems were arising in detailed with individual mandatorship, for example, no specific reasons for setting up zoning with individual mandatorship, it appears that municipalities do not plan areas that obviously would otherwise be used as a public place. Injustice arises when property owners have to pay construction and maintenance of the road in a public place while they pay municipal taxes that finance public places. Problems in implementation was identified in plans with individual mandatorship. The thought out community unions does not tend work in practice.

    With these problems a thorough study of the problems municipalities had with individual principal responsibility of the plans have been completed, treating how it is supposed to implement a change from the individual to the municipal mandate for the public space.

    The purpose of the study is to examine these municipalities that dealt with the issue surrounding the principal responsibility for the public space in plans. Furthermore to investigate whether the municipality experienced problems with individual principal responsibility for the general location based on the information that Boverket mentions in the spaning - Huvudmannaskap innebär svårigheter. The aim is to examine how local authorities are performing a change from individual mandatorship to municipal mandate in new and existing plans.

    The study was conducted according to a cross-sectional design, which means that both a survey and interviews were used. To find out which municipalities we could use in our study we sent out a survey, 21 municipalities were selected from the answers and 13 of these municipalities were interviewed.

    The result shows that most municipalities want to make a change based on similar grounds. Municipalities have different ways of dealing with the transition from the individual to the municipal mandate in the plans but the most common way is to change the existing plan. In summary, we think it is positive that municipalities address the issue surrounding the principal responsibility. We believe that the majority of municipalities handle the problems properly and make decisions based on the right reasons.

  • 21.
    Back, Cornelia
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Gustafsson, Julia
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Kartläggning av Stockholms, Göteborgs och Malmös hantering av miljonprogramsområden: ur kommunernas och de kommunala bostadsbolagens perspektiv2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The million programme is a building era that took place between the years 1965 to 1974 when a politic decision was made to build a million new residences in Sweden, to correct the housing shortage. It´s now been more than 40 years since these residences were built and the need to renovate is a necessity, which makes this programme a very current subject. The purpose of this study is to map the three largest city´s handling of the need for renovation. The main question of this study is how the buildings of the million programme is being handled today. Meanwhile a series of other questions have been answered in this study; the difference between laws now and then, how the million programme areas looks in the different cities and how they are treated in the layout plans, what the need for renovation might lead to, and if there is any profit in restoring the buildings.It is a qualitative study as it is a situation in a few cities that are being studied, but through a survey this study gets a quantitative mixture as well. A survey was dispatched to the three municipalities and their communal real estate companies.Malmo, Gothenburg and Stockholm are both similar and different regarding planning and visions. Both Gothenburg and Stockholm placed their million programmes outside of the city´s core, whilst Malmo´s was located close to the centre of the city. They all have visions in their layout plans to create a more unified and connected city through increased integration and better communication between the city areas.There was a wave of renovation in the eighties and nineties because of the ROT-deduction and many projects concerning the million programme are still ongoing to this day. Facade renovation is common in all three cities and, to a certain degree, restoration of balconies and windows. Gothenburg has invested a lot in energy efficient measures and in Stockholm it has become increasingly more common with energy saving interventions like adding increased isolation. The image of the million programme´s constructions is "concrete ghettos", but the most common houses consists of three storeys with apartment size 3 rok.The Swedish legislation are of great importance during the renovation as there now are requirements on energy efficiency amongst other things, but also during the wave of renovation in the eighties and nineties when the demand of discretion was enforced in PBL 1987. The foundation in the million programme houses is satisfactory and they are functionally built which makes a renovation more cost-efficient than it would be to tear it down and build new buildings. The problem then does not reside in the need for renovation, as most houses needs restoration after so many years, but in the sheer number of buildings that would require a renovation.

  • 22.
    Baric, Velibor
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Mugisha, Arthur
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Elkvalitetsmätningar vid Högskolan Väst och kartläggning av hur elkvalitetsutredningar hanteras vid elnätbolag2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today voltage quality is important in society, and with the constant continuing development of new modern technological products also makes people more demanding market and its products. This report describes the regulatory requirements on power quality and describe how a power quality works in practice. A clear written guidance on electrical connectivity have been performed in order to get clear instructions on how to connect today's instruments. Measurement has been conducted at University West for 24 hours using the school's equipment and with the help of an experienced supervisor. Furthermore, the report will include what affects the power quality and the consequences that may occur when there is poor power quality in the electricity grid. A distinction has been made on three network companies in Sweden of different size. The three network companies are Vattenfall AB, Göteborg Energi Nät AB and Trollhättan Energi AB. The survey has been done through interviews with officers and electrical engineers. The reason for this limitation is performed to find out if there are any established routines on how network companies handle customer complaints and unsatisfied customers. In addition, the report will describe the differences and similarities how these tree network company handled customer complaints. After interview with electricity suppliers can be concluded that there are few costumer complaints/cases per year from customer to the electricity supplier given how many customers it has. The result for measurement on voltage fluctuations, harmonics and flicker shows accordance with standards accepted values and it can be stated that University West has strong network.

  • 23.
    Bengtsson, Emmy
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Svensson, Anton
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Små och okomplicerade projekt inom infrastrukturplanering: En studie i hur Trafikverket använder typfall 12015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Spatial planning of land and water is an important part of a community’s structure and development. Community planning is a democratic process, regulated by several laws and it’s contributing to a sustainable living environment from a social, ecological and economic perspective.

    Trafikverket (The Swedish Transport Agency) is the authority in Sweden which is responsible for infrastructure planning. According to the Swedish Road Law and Railway Law, the one intending to build new infrastructure, must establish a road or railway plan, which often is a long and costly process. In January 1, 2013 changes were introduced in to the law to exclude small and uncomplicated projects from the formal planning process, to create a more effective infrastructure planning system. These small projects were given the name type case 1 (typfall 1), in the planning system of Trafikveket.

    The purpose of the study is to examine how the changes in the law from 2013 have been used in the planning process by Trafikverket. The study intends to investigate which type of project the law changes has applied on and how they conform with the intentions that they should be small and uncomplicated. It will also investigate how the changes are received and perceived by those involved in infrastructure planning.

    The methods used to answer the questions is document study and focused interviews. The documents study includes all the planned projects from Region Väst (Western Region) from 1 January 2013 to 31 December 2014. The interviews were conducted with project managers and consultants who all have experience in the planning of small and uncomplicated projects.

    The results shows that Trafikverket mainly uses the new changes in the law to build bus stops, left fields and roundabouts, and it has been applied to significantly more road projects than railway projects. The projects is varying in size since the new guidelines have been interpreted in different ways.

    The conclusion is that changes in the law have contributed to a more efficient planning process. The project managers overall have a positive attitude to implement smaller projects without a formal plan, but the guidelines on witch background material needed for a project should be more clear.

  • 24.
    Berg, Gustaf
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Brattlöf, Magnus
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Distributed Checkpointing with Docker Containers in High Performance Computing2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Lightweight container virtualization has gained widespread adoption in recent years after updates to namespace and cgroups features in the Linux kernel. At the same time the Industrial High Performance community suffers from expensive licensing costs that could be managed with virtualization. To demonstrate that Docker could be used for suspending distributed containers with parallel processes, experiments were designed to find out if the experimental checkpoint feature is ready for this community. We run the well-known NAS Parallel Benchmark (NPB) inside containers spread over two systems under test to prove this concept. Then, pausing containers and unpausing them in different sequence orders we were able resume the benchmark. After that, we further demonstrate that if you carefully consider the order in which you Checkpoint/Restore containers, then the checkpoint feature is also able to resume the benchmark successfully. Finally, the concept of restoring distributed containers, running the benchmark, on a different system from where it started was proven to be working with a high success rate. Our tests demonstrate the performance, possibilities and flexibilities of Dockers future in the industrial HPC community. This might very well tip the community over to running their simulations and virtual engineering-applications inside containers instead of running them on native hardware.

  • 25.
    Berg, Gustaf
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Larsson, Daniel
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    En jämförande studie av tekniker för trådlös platsanalys vid Universeum2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis a comparison between a predictive site survey and two passive site surveys is performed, to see if only a predictive survey is enough to estimate a well-functioning wireless network. Some fundamental facts and techniques that are involved in wireless networks are presented and also the method of how the site surveys were planned and performed. The outcome is compiled in diagrams. The difference between a predictive and a passive site survey is analyzed, and shows if the prediction is trustworthy or needs to be verified.

  • 26.
    Bergkvist, Sofia
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Runge, Johanna
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Allmänna och enskilda vägar: Väghållaransvar utanför detaljplanelagt område2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In terms of traffic, in order for the infrastructure to work it requires that the road network fulfills its function. Communication between the different parties, the Swedish Transport Administration (Trafikverket), municipalities and individual property owners is important, and situations with conflicts and disagreement are easy to evolve. Which part should manage the operation and maintenance to a certain road and what the laws say about each road are sometimes unclear. The Swedish Transport Administration, municipalities and individual property owners are the three different parties that can be responsible for operation and maintenance, also known as road holders, by roads. If the road is located within or outside of the planned area depends on which legislation is applicable. Planning and building act (PBL) and road legislation (VägL) are the laws used inside the planned area, but so is the plant legislation (AL) in the formation of community facilities. It is mainly the planning and building act that is applied because it regulates the planning, the road is then named street according to PBL, but in some cases the municipalities may choose to plan the road according to the road legislation. In cases where the road legislation is applied the process is more extensive and for this law to apply, the roads must be public. Outside planned area there is no law that regulates in the same way as the planning and building act, instead the plant legislation is applied for the individual roads mainly to establish a community facility. It is at the establishment of the community facilities the statutes are set, these regulate the operation and maintenance of the road which concerns the individual property owners. The study includes a survey conducted to 49 municipalities in the county Västra Götaland. Four of these municipalities were then selected for a further interview. The Swedish Transport Administration and National federation individual roads (Riksförbundet enskilda vägar) were also interviewed, this in order to get an overall view and not only information from different municipalities.The result is based primarily on the interviews but also the answers from the survey. The information that emerged from the interviews with the municipalities differs from the answers received from the survey whether the municipalities experience problems with managing individual roads. Instead, the municipalities mean that there are generally more problems in the planned area than outside. The result also indicates a variation between the municipalities, while the Swedish Transport Administration has clear limits on the selection of road holders. REV addresses the problem of the difficulty of getting people to arrange  ii Allmänna och enskilda vägar – Väghållaransvar utanför detaljplanelagt område  the board work on an individual road. The definition of public and individual road differs between the different interviewed parties. The study reflects on distinct guidelines for when a road should be public respectively individual in order to clarify the boundary of when road maintenance takes over and another ends.

  • 27.
    Berndtsson, Jesper
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    By, Mathias
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Analyzing and improving a wireless network2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about how a site survey is carried out using software and how a site survey can collect the information needed to improve the existing wireless networks. The report provides both general information about wireless networks and practical examples with authentic measurements in the corporate environment.

    Problems can arise in a wireless network if the planning is not properly done. A measurement have been made in second floor, where company X is located.

    The results of the survey is presented in images that show the strength of Company X wireless networks, on the second floor. Images also shows noise, overlapping channels and how the signal strength related to these.

  • 28.
    Berndtsson, Jesper
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    By, Mathias
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Analyzing and improving a wireless network2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about how a site survey is carried out using software and how a site survey can collect the information needed to improve the existing wireless networks. The report provides both general information about wireless networks and practical examples with authentic measurements in the corporate environment.

    Problems can arise in a wireless network if the planning is not properly done. A measurement have been made in second floor, where company X is located.

    The results of the survey is presented in images that show the strength of Company X wireless networks, on the second floor. Images also shows noise, overlapping channels and how the signal strength related to these.

  • 29.
    Berndtsson, Jesper
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    By, Mathias
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Cactuz: The modular toolbox for evaluating Intrusion Prevention Systems2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Intrusion prevention systems are a widely used today to protect the local network from threats on the world wide web by blocking unwanted packets, but still be able to forward desirable traffic. Before placing the intrusion prevention system in a live network, the system can be tested with it capabilities in a test environment.

    This paper is about the build of the toolbox "Cactuz", developed with 11 different test sce-narios with the availability to expand. The report contains general information about threats and attacks but also the software and tools included in the build. The result of the build is presented as the toolbox which includes multiple attacks and tests with a user interface. Cac-tuz is evaluated by Snort IPS where the evaluation of each attack is presented and analyzed.

  • 30.
    Bertilsson, Oskar
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Kartläggning av kommunalt nätverk: med granskning av enhetssäkerhet2017Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This thesis is about mapping of a municipal network and evaluation of the security on the network devices. The evaluation of the security was done simultaneously as the mapping of the network. Solution of any security flaws will also be included in this thesis. The mapping of the network was made by looking at the configuration of the devices. Telnet was used to access the configuration of the devices. Biggest part of the mapping was done with information given by Cisco Discovery Protocol (CDP). To create the map of the network Microsoft Visio was used. The municipality had an old map of the network that was copied and modified. The security was examined by inspecting which protocols and settings that were configured on the devices. Results of the mapping showed that the network is a flat layer 2 network. It was only configured for layer 2 except the links out from the network. The devices in the network were mostly layer 2 switches but it had some layer 3 switches. Comparing the old map with the new map showed that the network had been expanded and some switches had been moved around. When examine the security of the devices it showed some security flaws. Since the network was complete layer 2 network, the focus was on the layer 2 security. The biggest security flaw that was discovered were the use of Telnet instead of SSH. VTP did not have any password set since it was version 1. Some trunk ports were open even though it was not in use. CDP was in use all the time which could give an attacker lots of information. Mapping the network was done without any major problems. The security flaws that was found was presented to the municipality together with a solution for each flaw.

  • 31.
    Beyrouti, Magdalena
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Larsson, Patrik
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Beredning av landsbygdsnät Restenäs-Andorra i Uddevalla kommun2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is about how preparation work is accomplished by contracts and permit search to network planning and dimensions. The requirement for reliable electric power increases because electricity is such an important part of our society. Large disruptions cause significant costs for electric distribution companies and customers. . To increase reliability and make the power grid weather secured, overhead lines are replaced with underground power cable.

    The preparation work is preformed to weatherproof the electric power grid in Restenäs-Andorra outside Ljungskile in the municipality of Uddevalla, by placing power cable in the ground instead of overhead power lines. The project will be implemented in connection with the development of communal water and sewer to reduce the cost of excavation.

    The result of this preparation work includes a new 10/0,4 kV substation, four cable boxes together with 1200 m of high voltage power cable and 800 m of low voltage power cable. The electric transmission network has been placed in the same excavation as water and sewer as long as possible. The substation and cable boxes are placed for easy access and to create a good mesh. A P2-calculation has been created to get an overview of the costs of the project.

  • 32.
    Beyrouti, Samer
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Yaghoubipoor, Mohammad
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Standardisering av reläskåp för transformatorstationer2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis is a case study about standardization of a relay cabinet at E.ON´s 55/11 kV substation. Standardization of the relay cabinet implies that a solution is developed from a station and applied to other stations with the same conditions. Prior to the development of the relay cabinet, a basic theoretical study was performed about the external and internal faults that a transformer may be exposed to and the most common transformer protection philosophies were investigated. In addition to relays other components in the relay cabinet were also examined. The project was then divided into parts where control of the assigned data and circuit diagrams were performed. The material consists mainly of connection charts and circuit diagrams that describe the station and cabinet construction and the components used at present. The charts for the existing devices in the relay cabinet were examined extensively. In combination with E.ON's requirement for the cabinet components and the transformer station the components technical specifications as well as the protection functions were established. A request for quotation was sent to the leading manufacturers with the component's technical specifications. The answers provided by the suppliers were analyzed and then compared with the existing ones. A request was also sent to relay cabinet installation companies. Only one company was able to perform the work. All data was then compiled and analyzed. Following the study of the market leading manufacturers relay D, voltage regulator F and annunciation relay H were chosen as the best recommended components. Other products that have some advantages are analyzed and discussed in the report. The only installation company that responded was chosen to perform the installation work.

  • 33.
    Birgersson, Patrik
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Svensson, Martin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Utvärdering av möjligheter för semiautomatisk reläskyddsprovning med Omicron CMC 3562017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When energy companies undertake the maintenance responsibility for their power plants and facilities the protection systems may be tested by different contractors. As a result, the testing procedures may differ between facilities. In order to achieve a more similar testing of the protection relays they should be tested the same way every time. Testing of relays are usually performed by experienced personnel that may employ in slightly different ways of testing due to the lack of one which is standardized. This leads to a situation where the knowledge within this area of work stays in the minds of only a few employees of the company.

    The reason for this project to be made is the employers wishes to investigate if the testing of relays can be performed in a more similar way in order to achieve comparable results and to minimize the risk of mistakes made during the testing.

    With Omicron CMC 356 and the associated software "Test Universe 3.10" it is possible to program tests in advance and bring to the station and implement the prepared tests. This report is performed as a pilot project to show the client how the tests can be programmed and how Omicron might be implemented in the maintenance testing of their relay protection.

    The report begins with a theoretical review of the functions that the thesis comprises. The construction of the relay with the principles it uses are explored, the limits and accuracy for the measurements are also reviewed. The thesis is because of time constraints limited to testing the functions: overcurrent, overvoltage, undervoltage, underimpedance, as well as differential and frequency protection. The thesis also contains a practical part in which testing of the relays was completed in a hydropower plant. Omicron CMC356 was the testing equipment used along with the related software "Test Universe 3.10", where the testing functions were programmed. The modules used for testing the relay functions are described along with the essential parts needed to test the functions that the thesis comprises.

    The conclusion of the thesis is that several of the functions needed can be performed automatically. A decision has to be made about the balance between economy and quality because of the initial work that have to be made to program every station that is meant to be tested in this way.

  • 34.
    Bjurelid, Martin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Murina, Emran
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Analys & kartläggning av Uddevalla citys mellanspänningsnät2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The demand of reliable power distribution is increasing as the usage of power is increasing in the society of today. Overhead lines are replaced by underground cables, availability to reserve power supply and power quality is of high priority.

    The condition of the equipment deteriorates over the years and will eventually have to be replaced. By request from Uddevalla Energi, values have been provided concerning voltage drop, capacitive ground fault current and loads during normal operation and standby power supply. The types and ages of cables in Uddevalla City’s high-voltage network has also been looked at. This report presents these results and gives some suggestions for modifications if required. Planned future deployments are looked over and how these may affect the network.

    To obtain these results the network calculating program "DpPower" was used.

    The calculations presented shows that in normal operation all values are approved within the company standards that Uddevalla Energi follows. For the reserve supply however, some lines are overloaded. The analysis shows possible solutions for these issues. Age and status of cables in the network varies widely, making it difficult to specify how redevelopments should take place. Instead the overloads should be given more consideration.

  • 35.
    Blomberg, Charlotte
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Söderqvist, Linnea
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Andelstalsfördelning för gemensamhetsanläggningar i tredimensionella fastigheter2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is currently no common way of apportioning participatory shares in joint facilities in 3D property formation. One reason is that 3D property formation is relatively new and previously used only to a limited extent, but today it is becoming more common as cities are densified and growing in height. This leads to a more complex property formation with more common spaces and facilities. The purpose of this thesis is to create a model for apportioning participatory shares that can be used in 3D-based facility procedures for joint facilities with the purpose of elevator. The idea is that the participatory shares should be easy to understand, while at the same time experiencing fairness by the property owners as well as giving a general picture of reality. The method that is used to obtain the calculation models is statistics on the number of journeys in lifts, as well as surveys of areas and visitors to different types of properties. Further methods used are discussions with several surveyors and analysis of collected materials and results. The model developed uses the “tonkilometermetoden” as a basis. In the same way as “tonkilometermetoden”, the apportioning is divided into two steps to obtain a transport number and then a length number. The transport number corresponds to the number of elevator trips a property generates and is calculated using models depending on the type of activity in the property unit. The work generates calculation models for property units with the purpose of housing, office, restaurant, preschool and dentist. For other types of property units there is only an indicative discussion. The length number is determined by the floors used by the property unit. The model for the length number leads to two proposals for how the length number can be calculated and differentiated with respect to the floor, with a linear curve or an exponential curve. The two solutions are compared and their advantages and disadvantages are analyzed. The transport number and length number are then used together to obtain the participatory share that the property unit receives.

  • 36.
    Bodestål, Emil
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Jakobsson, Daiel
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Metoder för att minska risken för sympati-utlösning av Vattenfalls transformatorstationer2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This Bachelor's Thesis has been produced in cooperation with Vattenfall Eldistribution AB. In the center of operations in Trollhättan, they manage their electric grid in Sweden. During the energizing process of a transformer in parallel with another one in use, the station sometimes becomes disconnected. This phenomenon is called "sympathetic disconnection". It occurs in some way randomly and is fairly uncommon. At Vattenfall it occurs a couple of times every year. This means that there are few cases to study and therefore most of the project is based upon interviews and one well-documented case. Based on that case, a computer model was created in PSCAD EMTDC and modified to create a situation where the phenomenon always occurs.

    The goal for this project was to find some strategies and test those in PSCAD to see if they would make the situation better. The different types of strategies tested are to change the point of circuit-breaker operation, the tap changer, an alternative energizing from the secondary side, different winding connections and the significance of a strong network. A theoretical analysis of the importance of an inrush limiting resistor and synchronized switching was also made.

    The results show that the time of the circuit-breaker operation is of great importance. With support of synchronized switching an energizing can be done completely without affecting the feeding grid, nor the parallel transformer. Individual breakers seems to be worse than just sensing the voltage zero crossing and operating all the breakers simultaneously. The simulations have shown that some measures can improve the chances of a successful energizing. The tap-changer should be set in the position with the largest ratio. A wye-delta connected transformer is better than a wye-wye connected, which is the standard at Vattenfall. It is also standard to energize transformers from the primary side. Simulations have shown that an energizing from the secondary side would result in several benefits. At last, a strong network is preferred.

    The earth-fault protection relay in the feeding line is most prone to cause a disconnection. Therefore, depending on the situation, a change in the time setting in the relay's fourth step should be considered.

  • 37.
    Bolander, Ola
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Erving, Ivar
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Elkvalitetsundersökning vid Sahlgrenska sjukhuset2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On behalf of ÅF Consult an electrical power analysis has been made for Västfastigheter at a switchgear at Sahlgrenska University hospital in Gothenburg. The intention is primarily to investigate the data of most interest to the customer such as variations in voltage, imbalance in supply voltage, voltage harmonics, power consumption and neutral conductor current. In addition, Västfastigheter have requested an investigation of a vibrating busbar trunking supplied from the switchgear. The starting point of thesis work is a theoretical background described in the first part of the work and the goal is to deliver a good basic understanding of the concept of power quality.

    Measurements have been carried out both when the system was fed from the normal supply as well as during a 6 hours long test of the backup power supply system. The result at normal supply showed, according to current regulations, that all parameters are approved except for harmonics number 9 and 15 for which to high levels are detected. When the load was fed from the backup power supply the results show no significant changes compared when the load was fed from the normal power supply. However, some noticeable phenomena linked to the voltage and the current waveforms are noted. They are of interest for getting a deeper understanding of the different supply modes. In backup supply mode the grid impedance increases, this is normally described as the grid becoming weaker. This is shown as increased imbalance between the voltage levels of the three phases. It is also characterized as the current distortion having a greater impact on the waveform of the voltage leading to a larger level of voltage distortion compared to normal supply.

    The connected load on the vibrating busbar trunking is examined with a power quality analyzer and vibrations are measured by an accelerometer. Since the degree of the vibration decreases as the electrical power is unloaded throughout the different levels at Sahlgrenska, the theory is that they are related to the level of the current. To further strengthen this theory reference can be made to two adjacent busbar trunking of the same type that are considerably less loaded. They have noticeable vibrations but with a much lower magnitude, which is comparable with how the investigated vibrating busbar trunking behaves further out.

  • 38.
    Borgmalm, Tomas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Schüllerqvist, Ola
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Bygglovets giltighetstid: Och hanteringen av justeringar efter bygglovsbeslut2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    How long a building permit is valid is regulated in the Swedish planning and building act (PBL) 9:43. The validity of the permit is defined as the actual works with the building must be commenced in two years and ended in five years. The main question in this study is about the difficulty in assessing whether the actual works with the building has been commenced. There are few law cases that define the meaning of "commenced", which probably means that municipalities make different interpretations of the issue. Another question the study addresses is how changes in building permits are handled after the permit has become valid. Reasonably it happens that developers need to make adjustments of the building permit during the actual construction.

    The aim of this study is to examine how municipalities interpret PBL 9:43 with respect to the term "commenced" and how the building permits limitation of two years is complied with. Furthermore, the purpose is to give a description of the legal basis of what is meant by "commenced" in the current legislation. The study also intends to investigate whether PBL provides the ability to adjust the building permit during the time of the construction, and how municipalities deal with such cases in practice.

    The study is based on a legal analysis that aims to describe the legal grounds surrounding the building permit and especially the rule in PBL 9:43. To examine how the two-year period is complied, a quantitative survey of 500 building permit documents in six municipalities was completed. A questionnaire was sent out to 75 municipalities to provide answers to questions about the municipalities interpretations of "commenced" in PBL 9:43 and how adjustments of building permits are being handled.

    The outcome of the legal analysis shows that work with a building's foundation is probably a requirement that is needed for the work to be assessed as "commenced". The questionnaire survey reveals large differences in how municipalities interpret "commenced" in PBL 9:43. It also shows that half of the municipalities do not perform any active controls of the building permit's two year limitation. The investigation reveals that it is common that developers make adjustments during the time of construction and that most municipalities deal with it within the existing building permit. The investigation of building permits shows no case where starting clearance was given after the two year limitation.

    We conclude that a clarification of the legislation would likely provide a more uniform assessment of "commenced" in the municipalities. Likewise, it is unclear what support PBL provides considering adjustment after the building permit has become valid.

  • 39.
    Bou Nassif, Nizar
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Abdallah, Ali Waddah
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Google Drive, Dropbox and OneDrive - A Comparison from a Security Perspective2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to examine what security issues exist in cloud storage services. We examine the solutions offered by Google Drive, Dropbox and OneDrive and make a comparison among these three services from a security perspective. Cloud storage is one of the cloud computing services that has become popular in recent years because of the spreading of smartphones and tablets. According to previous theo-ries, there are many security issues affecting cloud storage. In this study we examined Google Drive, Dropbox and OneDrive from a security perspective. We did a compari-son between the solutions offered by these three providers.Our criteria were taken from the cloud security alliance that has a list over the most im-portant security issues affecting cloud computing. We took information about the secu-rity solutions from the providers' white papers and support sites.Our results show that the three providers have similar security procedures and that they use many security technologies like TLS, two factor authentication and defense in depth. Results also show that each one of them has a superior procedure in a particular area compared to the others, and that made it difficult to decide which one is the best.

  • 40.
    Bradley, Jonatan
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Höglind, Fredrik
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Anti-Virus resursutnyttjande2016Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    How does Anti-Virus software affect the computer performance? Avast, Windows defender, Eset Nod32 and Symantec are a few of the big Anti-Virus companies that specialize in protecting your computer by removing virus, malware and trojans. Four Anti-Virus software and three scenarios was chosen to test cpu, memory, networks effect of the Anti-Virus software. Every scenario were tested three times ten minutes for every Anti-Virus software. Five minutes composed of a baseline and no test performed, after five minutes we conducted the test. Results differentiated between the different scenarios. Altogether, the Anti-Virus software differentiated minimal between each other. The data showed that the free Anti-Virus software was every bit as good as the paid Symantec version in utilizing the computer resources.

  • 41.
    Brinkheden, Dan
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Andersson, Robin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    A Performance Study of Hybrid Mobile Applications Compared to Native Applications2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study evaluates the performance difference between hybrid and native mobile applica-tions when accessing the low level API. The purpose of this study is to find out the differ-ence in performance between the different methods for developing applications due to an increasing market for platform independent applications.

    Several benchmarks were created to measure the performance on the following criteria, execution time, memory allocation and storage space. The benchmarks were developed with a similar behaviour to match the functionality.

    The Titanium benchmarks were around 8.5 times larger in storage space and used 26-28% larger heap when it came to memory than the equivalent Android benchmarks. Android generally has a lower execution time than Titanium, however there are cases such as the math library where Titanium has a lower execution time.

  • 42.
    Britte, Johan
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Kratzer, Björn
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Ottersten, Christian
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Förutsättningar för mikroproduktion med vindkraft för Byggnad 73 på Innovatum2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today's society environmental friendly electricity is sought after. This thesis will discuss the prerequisites to produce electricity from micro production wind turbines adjacent to Building 73 Trollhättan, situated in an urban environment.

    This thesis compiles information about wind turbine technology and the laws, rules and recommendations to be followed while constructing a wind turbine in urban environments. A market research of the Swedish micro wind turbine market has been concluded. From the market research results two suitable wind turbine proposals has been presented. During the process it was revealed that there are different definitions of micro production. There is also many different laws, rules and recommendations that you have to consider while constructing a wind turbine. It was established that it is important to examine the prerequisites of the environment in the area where you plan to place the wind turbine for example you have to consider obstacles and average annual wind speed.

    The prerequisites of the building were established and contact with Kent Andersson building-and equipment manager was made. We discovered that the electricity contract was too large for connecting of micro production and the construction of the building was too weak to support the weight of a wind turbine. Even though these aspects were disregarded we came to the conclusion that wind power in an urban environment is not appropriate for many different causes. But micro production in form of wind power is suitable in a rural environment where many of these causes do not exist.

    The group has disregarded these aspects when the two wind turbine suggestions were formed. Of these two suggestions one is mounted on the roof and the other on the ground besides the building. The two wind turbines that came to be chosen were Winden 30 and Villaverket Maglev 10 kW. Winden 30 is a wind turbine with an effect of 30 kW that should be placed on the ground beside the building and is made in Sweden by Winden Sweden AB. Villaverket Maglev 10 kW which is made by Nordh Energy and is supposed to be placed on the roof of the building.

    In this thesis the economic aspects of wind turbine construction has been disregarded.

  • 43.
    Broman, Therese
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Plan- och bygglagen: En planprocess i förändring?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The municipality is responsible for planning land and water use within the municipality. The municipality determines, through its planning monopoly was and what gets built. Today, there are parts of the country problems with the housing shortage that is partly a consequence of our society has undergone great changes. The changes have largely been the household composition, age distribution and geographical distribution of the population. In addition, there are built new homes sufficiently. For this reason, several investigations and studies conducted over the years to identify which part of the planning process that takes time to come to terms with lengthy planning processes. The aim has been to develop solutions to the problems identified in order to speed up and streamline the planning process as well as to simplify legislation. Weaknesses in the application is another reason to simplify the legislation but also need the skills increased in both the municipality and the state. Efforts skills development has been made by, among other things, Building and Planning and the stakes are even supposed to continue. The question then is whether it led to any change in the planning process?The study aims to describe the plan development of the process of trying to find out about the legislative changes made since the Planning and Building Act became final in 1987, have led to any change. The aim is also to try to find out whether the standard procedure will be applied more widely and if that means a faster process. Since the municipalities and the provincial government has an important role in the planning process, their views on the planning process contribute to transparency in various parts of the process and the municipalities to the amendments. To obtain county administrative and local views was conducted empirical studies. Data collection for the theoretical part is mainly relevant legislation and preparatory works studied. The study is both a quantitative and a qualitative study where both quantitative and qualitative data presented in the report.The result of the study is that municipalities themselves do not think that any major change in the planning process has taken place. Some changes have nevertheless taken place even if it has been at various times over a long period and in small dose at a time. Changes in legislation have resulted, if not faster, so at least one more functional planning process and a clearer legislation. The conclusion is that it really does not matter which procedure applies without ultimately is about every single detail plans complexity. To achieve the highest possible efficiency means achieving minimum time consumption without affecting quality, and there is the planning process is not yet.

  • 44.
    Bryntesson, Markus
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Rasheed, Nihro
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Omprövningsförrättningar enligt AL 43 §: En studie där omprövningar utvärderas med hänsyn till kvalifikationsgränser I AL 35 §2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to have facilities, which are common for some properties, functioning in a purposive manner for several users, the concept of joint facilities are established in Sweden. In ordinary cases in order to manage the joint facilities is to organise a joint property management association by co-owners of the properties. After the establishment of a joint facility, a need for changes or adjustments of that could arise. To implement these changes, a new cadastral adjudication procedure, under § 35 AL, can be applied, where the adjudication of the joint facility is re-exercised there.

    In order to perform a reconsideration for an adjudication, one of the three criteria of § 35 AL should be met. In order to have the permission to modify the issue as a cadastral procedure again, the material criteria of AL 5-11 §§ need to be met as well. The goal of this project is to study the different criteria of AL § 35 and new cadastral procedure adjudications from the archives of the municipal cadastral authority. The main purpose of this work is to assess to what degree the new cadastral procedure adjudications apply and fulfil any criterion in AL § 35.

    Those three criteria governing whether it is possible to perform a new cadastral procedure, regarding a joint facility, are changed circumstances, a clear need and a deadline stated in the previous cadastral procedure. The actual definitions of the first two criteria are not clear from the law, and therefore there is a difficulty for cadastral surveyors to assess and apply AL § 35.

    In our study, 2.5% of total number of the analysed acts do not or doubtfully fulfil any criterion of AL § 35. In 15% the new cadastral procedures some unclear issues are seen, which put a question mark in front of the work of the cadastral surveyors in using and applying the paragraph, but the acts were done in any case.

    The results of this project show that most of the assessed cases fulfil one of the necessary criteria, but despite this there are clear shortcomings in how AL § 35 is applied. It is often difficult for cadastral surveyors to know how this paragraph is assessed and applied, and which trial to apply for each criterion. Clearer and better explanations of these criteria can contribute to a more accurate and efficient cadastral procedure reconsiderations.

  • 45.
    Bäcklin, Staffan
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Jämförelse av svarstider för olika bilddatabaser för Javabaserade http-servrar2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis concerns databases in Java-based imaging system where the images are stored and retrieved as binary objects. In MySQL and in some other database management systems this format is called Blob (Binary Large Object). For the imaging system to work well, it is necessary to use a fast database.

    The aim has been that out of a sample of databases designate the database that is the fastest in terms of response times for downloading images stored as binary objects in databases. The databases are the four well-known database management systems MySQL, MariaDB, PostgreSQL and MongoDB.

    The tests have been conducted with the databases integrated into Java-based client-server modules in order to as much as possible mirror the conditions prevailing in an imaging system. The test tool that has been used is JMeter which is an advanced application for measuring response times and PerfMon to monitor the consumption of system resources.

    MongoDB was the fastest image database, but there are many uncertainties that must be considered, which is also explained in this bachelor thesis.

    Although many measures to counter the uncertainties have been made, the measurement uncertainty remains big. Further measures to isolate the database part of the response times in a client-server system must be made. Proposed measures are described in this bachelor thesis.

  • 46.
    Carlander, Isabel
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Holmberg, Malin
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Undersökning och exemplifiering av ett oriktat jordfelsskydd för detektering av dubbla jordfel i impedansjordade nät.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes problems that might occur with detecting and disconnection of cables and lines that have suffered from cross-country fault in impedance grounded networks, furthermore how and if an undirected earth-fault relay could affect the way these faults are dealt with. When single-phase earth-faults occur, the network suffers from a dissymmetry. This dissymmetry leads to enhanced stress on the parts of the network which are healthy. This stress could cause other earth-faults to occur, for example on locations in the network where, for some reason the insolation has been compromised. These problems could lead to that the time it takes for the relays to disengage the faulty cables becomes too long or that unnecessary large areas of the network are disconnected. The purpose of this study is to illustrate these problems and to analyze in what way an undirected earth-fault relay could affect the outcome of these problems.

    By examining theoretical cases where earth-faults had occur, files from actual disturbances and by verifications tests with relays in the laboratory and Comtrade-files developed from PSCAD, these problems could be analyzed and were easy to survey. As a result of the study it was found that the undirected earth-fault relay both can contribute to better selectivity in the network and to faster disconnection in the event of cross-country faults. The undirected earth-fault relay should also be able to handle additional cases when earth-faults occurs, for example, where a simultaneous uncompensated power distribution network leads to that the directed earth-fault relay functions does not work.

    The earth-fault function is recommended to be used with DFT-measuring, as this prevents the relay from tripping for harmonics, transients and direct-current components. A good knowledge regarding the capacitive currents occurring in the network is crucial to set the relay correct and prevent from unselective tripping, but if set correctly, no conflict with other protective relay functions has been noticed.

    The problem with disconnecting cross-country faults mainly occurs where two-phase-measuring overcurrent protective relays are used, therefore, the transition to three-phase-measuring overcurrent-relays are recommended in places where the undirected earth-fault relay proves to be difficult to set up correctly.

  • 47.
    Carlsson, Caroline
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lindesson, Julia
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Är det skäligt?: En studie kring skäl vid överklagade bygglov2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the current housing crisis, part of the social debate has been focused on streamlining the building permit process, and more specifically the ability to appeal a building permit. Proposals that emerged in the legislative history is to limit what and who has the right to appeal a building permit decision and the possibility to charge for the appeals. As the legislative history is only based on general statistics there is a lack of knowledge about what the complainant confided as reasons for the appeal. Nor is there any recognition on the grounds that wins the greatest success with the provincial government by matters referred back or canceled.

    The purpose of the study is to create a better understanding about the contested building permits and the function the provincial government fills as the appeal court. The main objective is to investigate the reasons behind the contested building permits, and investigate which of the arguments that have the greatest success for the complainants. To fulfill the purpose three questions were answered. What are the reasons invoked by the appellant? With what the reasons cancels and remits the provincial government municipal decisions? To what degree do the reasons cited by the complainant correspond with the reasons the provincial government cancels or refers cases?

    A quantitative content analysis was applied together with the legal method to interpret and classify the reasons. A statistical method has been used to compile and present the results. A total of 274 contested decision documents were reviewed and resulted in 197 documents considered as representative for the study. The review resulted in 77 categories of reasons cited by the complainants.

    The most common reasons were: significant inconvenience, the measure is contrary to the local plan, city- and landscape, cultural heritage and good overall effect is adversely affected, the neighbor hearing has not occurred, that there have been shortcomings in the documents and frivolous reasons.

    By far the most common reasons for the cancellation was that the measure is contrary to local plan and was not considered to be a little deviation. The most common reasons for the provincial government to remit cases were that the neighbor hearing had not occurred and that the building committee failed in its justification of the decision. Reasons cited by the complainant and the provincial governments reasons for the suspension or referral was consistent in 47% of the cases.

    Overall, the biggest success factors to cited reasons involving measures who is contrary to local plan or defects in the building committees' handling of building permits. As a whole the provincial government are considered to play an important role as a regulator and should therefore not be excluded from the instance chain.

  • 48.
    Carlsson, Mattias
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Systemanalys av eldistributionssystem på Preemraff Göteborg2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On behalf of the technology department at Preemraff, a system analysis of the electrical distribution system has been performed. The work consists of two parts, and its main purpose is to give a better knowledge of the plants status. In the first part, a model of the refinery’s electrical distribution system is built in a program for network analysis. The model is intended to help Preemraff’s technology department in both the daily operation but also for expansion projects and changes in the electrical distribution system. In the second part of the work, an analysis of a limited part of the plant is performed. The analysis consists of verification of short-circuit currents, selectivity and simulation of voltage drop during start of electrical motors. A rough check of free capacity in respective part of the plant is also performed.

    Theory to give the reader understanding of the various components function and mutual interaction is presented. Existing standards and their calculation methods are discussed. Additional attention is paid to calculation of short-circuits. The technical configuration of the electrical plant is introduced, followed by a description of the modelling with respect to suppositions and some special cases.

    The results show that the short-circuit currents are in an acceptable level in most part of the plant. In one switchgear, the short-circuit current are somewhat exceeded. Start of electrical engines does not contribute to a voltage drop above acceptable levels in the part of the plant that was investigated. With respect to selectivity the plant has the potential to achieve selective disconnection at most of the investigated points. It is shown that the present operation mode, with switched on breakers between the switchgears A- and B-side prevent selective disconnection. The selectivity analysis is performed with the premise that A- and B-side is sectioned. With those premises, it shows that some adjustment is needed to achieve good selectivity.

    The electric distribution system is mainly constructed to permit redundancy for the n-1 criteria. The results show that a few switchgears are loaded to the point that their transformers will be overloaded with a single transformer fault.

    At the end of the report, proposal on operation diversions that is considered to optimize the plant is given. Suggestions on investments that would improve the plant in an energy term perspective is also given.

  • 49.
    Cervell, Fredrik
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Pettersson, Isak
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Säkerheter i exploateringsavtal: En studie om hur säkerheter tillämpas iexploateringsavtal2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Land development agreements are used to divide responsibility for the financing and development of a detailed development plan which is arranged on land not owned by the municipality. The agreement is established between a municipality and a developer or private individual. Land development agreements were not specified in the act until a legislative change in January 1, 2015. A subject that was not specified in the act is how municipalities should use financial collateral in the land development agreement. Land development agreements involves the financing and constriction commitments for millions of crowns and the financing often take place afterwards construction is completed. If it turns out that the developer can´t perform their obligations in the land development agreement due to bankruptcy, the municipality may be required to complete and fund the developer's remaining commitments. If the municipality had stated in the agreement that the developer must perform a collateral to cover the amount corresponding to the developer's commitments, the municipality can redeem the collateral and thus secure the financing if a developer would become insolvent.

    The idea of the study is to examine if the Swedish municipalities are using collaterals in land development agreements. The ambition is also to identify what type of collaterals described in the land development agreements. Finally a deeper analysis will be made of the agreements for which a guarantee issued by a bank has been used as collateral. Land development agreements and guarantees from the Swedish municipalities were gathered via email. 120 municipalities did participate in the study, which resulted in ananalysis of 197 land development agreements and 35 guarantees.

    The result of the study shows that 58% of the 197 land development agreements contain collateral, 37% of the agreements did not contain collateral and 5% of the agreements had no need of collateral. The most commonly required collaterals by the municipality in land development agreements are any optional collateral that the municipality can accept, guarantees issued by a bank or insurance company, bail by parent company and mortgages on real estate property. The results also show that 69% of the 35 guarantees studied are ancillary to the underlying development agreement and 31% of the guarantees are independent in relation to the underlying development agreement. Ancillary means that the guarantees issued by bank is linked to the underlying land development agreement. Independent guarantee means that the guarantee is not linked to the underlying land development agreement.The final conclusion of the study is that awareness and clarity of collateral in land development agreements should be improved and that a statutory regulation of collaterals in land development agreements is preferable.

  • 50.
    Chmeis, Ali
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Halaoui, Mahmoud
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Modernisering av belysningsanläggning för kontorslokal2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Lighting is a big need in our daily lives. In recent years, the field of lighting has achieved significant improvements in energy consumption, brightness, environmental aspects and the lifetime of light sources. The outdated lighting systems are phasing out and are now being replaced by LED lamps.

    The thesis is based on establishing a more energy efficient lighting installation for an office premises in Gothenburg that has an area of 220 sq.m. and consists of 12 rooms. The work has been carried out with the entrepreneur Ljusproffsen Future Group Svenska AB, which has received a request from the customer to upgrade the lighting system to LED. The replacement to LED aims to contribute to a financial saving for the customer.

    An inventory for all light sources in the office premises has been established with a calculation of the total energy consumed. After that, a new lighting layout has been proposed using the DIALux evo lighting calculation program and the reduced energy consumption that can be achieved. The LED illumination covers all the requirements of the Occupational Safety and Health Act regarding workplaces and offices.

    The energy consumption has been reduced from approximately 2844W to 1581W. This corresponds to a decrease of 44%. The annual energy consumption is estimated at 6 324kWh based on 4000 hours of lighting each year. The life of the LED installation is 50,000 hours for the selected luminaires compared to the previous ones which have a lifespan of 20,000 hours. LED lights have proved to be a good choice for saving energy. The total luminaire light flow for the premises has increased with 21 000lm.

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