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  • 1.
    Abdalrhman, Slah Aldeen
    University West, Department of Engineering Science, Division of Production Systems.
    Virtual model of a production process: Seam sealing line at Scania2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of digital factories is becoming more popular among the manufactures due to its contributions in simplifying the work of plant engineers and reducing time to market of the products [1]. The main aim of this thesis was to investigate the possible applications of a digital copy of production processes by creating a virtual model of a seam sealing line in the paint department at Scania in Oskarshamn. The main usage of the virtual model was to perform offline programming of the robots. The benefits of offline programming were investigated and compared to online programming. Some comparisons between offline and online programming were made when it comes to the time needed for programming, the accuracy of generated robot paths, the workflow of both approaches and the required knowledge to turn from online programming to offline programming.

    The result of the conducted experiment showed that the time of robot programming can be reduced, and the accuracy of robot paths increases by implementing an offline programming tool. The other application of virtual which was investigated in this thesis was virtual commissioning. Virtual commissioning is a method used to test and validate robot and control (PLC) programs in a virtual environment before implementing in the real plant. The software in the loop was selected as an approach for building the virtual commissioning model after presenting the different existed approaches. The result of the model showed great benefits of virtual commissioning not just in reducing the time of traditional of the new built line but even when replacing parts in an already existing manufacturing. Virtual commissioning is still new in the manufacturing, therefore, there are many issues which should be solved to get an optimal model that imitates perfectly the real plant.

  • 2.
    Abdulkareem, Haji  
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Javidan, Mustafa
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Nätutvecklingsplan för området Hälltorp i Trollhättan2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    After many long power failure occurrences on the overhead line that feeds the receiving substation Torsred, and because of the household expansion in nearby area, Trollhättan Energi Elnät AB has decided that a new receiving substation that replaces the existing one should be built at a new location. This thesis includes investigation and calculation of a new electricity network and suggestions on how the new electricity network can integrate with the existing one. Also, a new selective coordination plan and new backup power alternatives are investigated.

    The existing receiving substation Torsred is fed by Vattenfall Eldistribution AB:s 130/10 kV transformer OT00 by an 1 km long overhead line. The neutral point in Torsred is connected to the high voltage bar and consists of neutral grounding resistor and neutral point reactor. The total load current in Torsred is 925 A and during short-circuit in the busbar 154 MVA short-circuit power emerges. The substation Ängen with a short-circuit power 138 MVA is an underlying substation to Torsred that feeds the areas Öresjö, Edsäter and Hjärtum. All the outgoing electric lines in Torsred and Ängen are protected with relay protection and with different time- and current setting on these relays is selectivity installed for the underlying electrical network.

    The new receiving substation is planned to be built near the feeding point OT00. According to calculations the short-circuit power in the new receiving substations will be 227 MVA and in Ängen 200 MVA. The capacitive current increases because the over 1 km overhead line is demolished, and additional 7,5 km underground cable is added on in the new electrical network. A neutral point reactor needs to be upgraded to a 20 A bigger than the existing one because of the increasing capacitive generation in the electrical network. The price to build the receiving substation will be about 9 Mkr. The existing receiving substation Torsred will be demolished and replaced with a new 800 kVA network substation which will be used to feed a couple of the low voltage network in the area Strömslund. The distribution substation Ängen will be modernized. The total price for the whole project is calculated to 11,4 Mkr.

  • 3.
    Abudaher, Mohammed
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Alomari, Kamal
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Energieffektivisering i köpcentret Sisjö Entré i Göteborg2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency means that energy is used in an efficient way that impacts positively on the environment and society.

    Sisjö Entré is a shopping center which has an annual energy consumption of 1 865 270 kWh, and according to Energy Authority, the recommended value is 1 530 000 kWh per year. That means that energy consumption at the center should reduce by approximately 18 % to comply with the recommended value. The mall consists of 17 stores and the thesis examines five stores which are Toys Я Us, Rusta, Burger King, Babyproffsen and Webhallen. Measurements are taken on ventilation and lighting installations with the aim of studying the loads in the stores that consume the most energy. The goal is to come up with suggestions of actions to reduce energy consumption and costs.

    We concluded that lighting consumes the most energy in the warehouses; Toys Я Us, Rusta, Babyproffsen and Webhallen, while the largest load in the restaurants (Burger King) is the kitchen, which accounts for 75 % of the restaurants total consumption.

    In Rusta, we discovered that the electricity meter showed a lower value than the true consumption. After investigation, we concluded that the fault could be either in the electricity meter or in its current transformer and must be addressed.

    We have given a proposal to replace parts of the existing lighting installations, and given suggestion for sectioning certain parts in some stores. Further, we have given suggestions for reducing operating times on the ventilation units.

    Based on the above proposals and energy calculations, we concluded that these five stores has the potential to reduce the annual energy consumption from 1 865 270 kWh to 1 576 670 kWh, leading to a reduction by 15.5 %. This reduces costs by about 228 000 SEK per year

  • 4.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of OpenRatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.  An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated a more robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness.  The source code, as well as instructions for installation and usage is public.

  • 5.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of Open RatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated amore robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness. The source code, as well as instructions for installation and usage is public

  • 6.
    Aguilar Gómez, Raquel
    University West, Department of Engineering Science, Division of Automation Systems.
    Investigation of a Flexible Manufacturing Scenario for Production Systems: Case study: GKN Aerospace Company2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays the globalization of the market has a direct impact to the companies. On one hand, gives them the opportunity to spread their business but on the other hand increases the competition and the efforts to succeed. This project is pursuing to investigate and design a system capable to take upon and optimize the production within functional shops by in-troducing automation. Although the system it would be a standard solution for the functional shops, a case study for GKN Aerospace Company with its specifications has been carried out. The task become trickier due to the aeronautic sector requires a lot of work and effort to produce their products. The items and materials are expensive as well as the processes and treatments thus the introduction of automation is quite complex. This case study has accom-plished a research through the concepts and options to introduce automation within this production process. Taking under consideration the costs and efforts that would demand the investment for automation, the project propose a new and innovative manufacturing system "Move & Play", suitable with the features and requirements GKN Aerospace Company may need.The system proposed has been designed regarding to features such as movability, modularity and flexibility. These features have been considered essentials in order to make the system worth it and cost effective. The job-shop approach that the company use in its production contemplate the continuous change of products and introduction of new ones. Hence, the idea is to use the "Move & Play" system when it is required along the production. As a consequence, this system will create a "local product flow" along that point in the production that will organize the rest of the production or "global flow". Moreover it is expected to apply the concept of "plug-in" the processes that the system need at each time and therefore give flexibility to the system. With that purposes, the work has studied three different designs of the "Move & Play" system. Each design have considered different aspects and disposition. These designs have been compared according with criteria such as geometrical, the capacity and investment needed and the cycle time spent. Finally a conclusion on which design is the most suitable has been stated as well as a future work to continue with the work has been proposed.

  • 7.
    Ahrnfeldt, Olof
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Användning av reservelverk för att minska avbrottstiden på grund av fel på mellanspänningskablar2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Every Network operator strives to have as few and short outages as possible. Network operators therefore work continuously to convert the overhead lines to cables. Therefore, there is a need to gather knowledge about outages on cables and look into methods to decrease the outage time. There are laws and guidelines that need to be taken in consideration that limit the allowed maximum outage time and that is why backup generators could be a method to prevent breaking them.

    Problems that can arise regarding cable outages are to locate the flaw. Visual troubleshooting is often not a viable option which requires that the prerequisites are good enough to be able to use other fault detection methods. Factors that could affect the possibilities to use other measurement methods are the length, number of joints and the surrounding environment of the cable.

    Backup generators are most commonly used for maintenance and to reduce the outage time. The generators are mainly connected at the low voltage busbars but with additional equipment as portable transformers it can also be connected to the high voltage busbars.

    The result of the work performed shows that there are different factors that affect the outage time and frequency. One contributing factor that leads to increased outage time is the length of the cable. It may be due to difficulties to locate the flaw or that the cable pass inaccessibility areas increases when the length of the cable increases. During the winter period the average outage time is longer as compared with summertime, but during the summertime the outage frequency is higher.

    Vattenfall have backup generators, portable transformers and diesel containers available for booking on the internal website. The most common time before a backup generator is connected is between three and four hours. By using backup generators, it would be possible to reduce the outage time on about 100 outages during the analyzed time period. The potential decrease of SAIDI by using backup generators has not been able to be calculated because of lack of data.

    Available data is based on what is documented and there have probably been more situations when backup generators have been used but not been documented. With access to higher quality documentation the analyzes could be done more accurate.

  • 8.
    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.

  • 9.
    Akram, Yasser
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Mirzad, Elias
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Studie av övertoners inverkan på relätripptiden hos ett elektromekaniskt överströmsrelä2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A problem that has been noticed in the electricity grid is the increase in level of harmonics. In some cases, there may also be currents or voltages with frequencies that differ from the fundamental tone and this leads to the grid having harmonics meaning that when loads and components in the electricity grid are not sinusoidal, harmonics occur. For example, an increase in these types of loads e.g. charging an electric car or computers, in the electricity grid gives rise to an increasing harmonic content.

    In view of the aforementioned, this thesis has been carried out in collaboration with the Megger Sweden AB, Stockholm, as the official client for this study. The purpose here is to study the effect of harmonics on the relay trip time of an electromechanical overcurrent relay that is installed in the power grid's control facilities.

    The tests are performed with the test instrument Sverker 900 and an electromechanical overcurrent relay, ASEA RI. For testing the RI relay, a Swedish standard, an upcoming international standard as well as instructions from the client have been thoroughly followed and applied. The results of the tests shows the difference between the trip time with harmonics and the trip time for the fundamental tone.

    Conclusions based on the results are partly that the overcurrent relay is slower at weak currents, that is 2.8A and 3A respectively, as well as for long trip times in relation to the behavior without harmonics. According to the findings conducted herein, there is no significant correlation between the presence of harmonics and the influence of the relay trip time on medium and strong currents, between 4A-8A, or on shorter trip times.

    By reason of the time constraint experienced in conducting this study, the results and findings reached leaves a sound potential and promise for future tests conducted at different harmonic levels. A future recommendation for similar studies will be to test only at low currents, long trip times and slow disk speeds as this would facilitate the possibility of fulfilling a more robust result analysis.

  • 10.
    Al Hayani, Musab
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Offline Programming of Robots in Car Seat Production2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Company Purtech in Dals-Ed manufactures molded polyurethane (PUR). Examples of products that include polyurethane are car seats. Robots are used to fill the molds with PUR and to apply the release agent (wax) in the empty molds.

    Turning from online programming into a graphical offline programming of release agent spraying robots is going to simplify the process by:

    1. Applying less of release agent to avoid polluting environment, to produce an easier removal of moulds, for the sake of homogeneous moulds and for economical saving in the cost of release agent
    2. Adaption of spraying paths to variation in production speed.
    3. Programming of complex spraying trajectories to deal with sharp geometrical subsurface
    4. Decreasing onsite programming time (when program a new workpiece or modify an old one); so that robots would be free for production.

    While turning into offline programming brought the challenges of:

    1. Impact of variation in the production speed
    2. Lack of 3D models of workcell’s equipments
    3. Robot joint configuration when paths and robtargets are in move.
    4. Physical Joint limits, Singularities & Reach limits
    5. Collisions within the cell space.

    At the end, the following objectives are successfully met:

    1. Adaption of spraying programs to variation in production speed by developing and embedding a method in those programs.
    2. Graphical offline generation of spraying trajectories and optimization of those trajectories to the Purtech condition of spraying allowed time for each carrier.
    3. Simulation of release agent spraying process; and producing of a well structured RAPID program that reflect the simulated process.

              

  • 11.
    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.

  • 12.
    Alléus, Jonas
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Dalin, Patrik
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Vass, Sebastian
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Planering av laddstationer vid flerbostadshus2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sales of electric vehicles grow annually which increases the need for charging stations on parking lots at apartment houses. This report explore both the technical and the economical aspects of electric car charging for Stenungsundshem. The types of electric cars available on the market that can be charged by energy from the electric power network is the Plug-in hybrid and the electric car. The most common type on the market is the Plug-in hybrid which is driven by an electric motor and an internal combustion engine. The electric car is only driven by an electric motor. Charging times for electric cars depend on if the charging station is designed with normal charging or fast charging. For home charging, normal charging is the most common type of charging where the car is fully charged after six to ten hours. The connection between charging stations and cars can be made by different types of connectors. The European standard is the Type 2 connector. Safety is very important when charging electric cars, Therefore, charging stations have been divided into four different safety modes. Safety modes differ depending on the type of communication available between the charging station and the car. Mode 3 is the standardized mode in the Nordic countries. Charging of electric cars can result in power peaks which the main fuse must be dimensioned for. Power peaks can be reduced by using some type of load balancing system where available power during the day is distributed between charging stations to keep the power consumption below rated power. Terms of how charging is done and installation of charging station must be in compliance with Ellagen. For easier compliance and clarification of Ellagen standards and regulations should be used. In this project cable dimensioning by power requirements for different amounts of charging stations has been made, PEX insulated aluminum cable is exclusively used within the project. The market of charging stations is explored to look at different solutions and costs for charging stations and routing of cables. The best option for Stenungsundshem is currently to install two charging station for charging outlets to four parking spaces. Contributions like “Klimatklivet” can reduce total costs of investments for charging stations and cable routing with up to 50%.

  • 13.
    AlNabulsi, Yasan
    University West, Department of Engineering Science, Division of Production System.
    Robot motion control based on 3D mouse tracking2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The manufacturing industry and associated systems are being developed in an increasing manner to cover the market needs, where the manufacturing companies are continuously racing and competing to achieve high productivity rate and better production quality. In this thesis work, an advanced method for motion control of industrial robots has been investigated and implemented. This method is based on motion tracking of a 3DSpaceMouse, which was used to perform movements by the operator. The benefits and disadvantages of this method were discussed in this thesis work. It mainly showed a high accuracy in response to the motion applied by the 3DSpaceMouse, and a great stability regarding the programming environment that was used to build it. The movements applied by the 3DSpaceMouse were successfully captured and stored in variables in the programming platform. The capturing and storing process was successfully created as a package and prepared to be exported for usage by other software. Complete simulation was performed for an industrial robot, and successful communications among the various hardware and software components of this solution were accomplished. This has formed a complete integrated solution that has also included a user-friendly HRI. This HRI made it easy and simple to track the motion control processes and establish connections with the robot controller. Thus, it can be considered a feasible solution for motion control of industrial robots, which can be used by the manufacturing companies. Several tests and verification processes were carried out to obtain accepted results and to succeed in implementing a working model. Some errors and unexpected events have appeared during the work, which required handling in order to achieve a working integrated system.

  • 14.
    Andersson, Andreas
    University West, Department of Engineering Science, Division of Automation Systems.
    Utredning av variablerna som påverkar storleken på brytspänningen i lindningskopplare2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The recovery voltage is the voltage that occur when the transition resistor in the tap-changer leaves its previous position during an operation cycle. The amplitude of the recovery voltage depends on the leakage inductance.

    If the leakage inductance is unknown, the recovery voltage can instead be calculated using a FEM-program called ACE (internal ABB-program) in conjunction with Mathcad. First, the reactances between the windings are calculated in per unit (p.u) using ACE and they depend on the winding layout. It is time consuming to use ACE and Mathcad and the task has been to investigate the parameters that affects the recovery voltage and to develop a simplified calculation of it.

    Through simulation using ACE of a number of different winding layouts one soon comes to the conclusion that there are simply too many parameters affecting the reactances. Although the simplified calculations that despite this has been developed, they soon prove to be too rough to be useful. Mathcad is even more complex with heavy calculations that are not easy to grasp.

    However, this thesis has given more knowledge about the way the reactances are affected by the geometry of the windings, even though it was not possible to in a reasonable way simplify the calculation of ACE and Mathcad.

  • 15.
    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.

  • 16.
    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.

  • 17.
    Andersson, Anette
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Bojort, Daniel
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Nätplan för fördelningsstation M5 Hålta2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the area of Tjuvkil on the west coast, about 16 kilometers west of Kungälv city, a new residential area is about to be planned for about 140 new houses and holiday houses turned into permanent houses. A grid plan will therefore be made to investigate if there are any flaws to consider for the 10 kV-net, before and after the introduction which the new load will cause on behalf of the houses, plus extra space for the installation of an amount of charging posts.

    The purpose of this thesis is to compile the grid plan which will make the groundwork for the power distribution grid under the M5 transformer Hålta, which contains the areas for the new settlement. Backed up by the software dpPower this work will point out the flaws such as thin cables where large load currents and voltage drop occur, and also the statistics for interruption for the five outgoing lines from M5. This work also shows the status for the transformer in Hålta and how the surrounding grids status will be affected during their backup of emergency power for the M5. This work shows the grid status in the 4 steps as present status, with new load, emergency power and solutions.

    The thesis's evaluation of M5 Hålta will result in a suggested change of cable for the line L501 to Tjuvkil, which will decrease voltage drop and lower load current to avoid interruptions on the grid. Emergency power is lacking for a large-scale consumer and can be fixed with a looped feeding instead of a single line feeding on line L503. The transformer M5 in Hålta is already heavy loaded and in need to be replaced by a larger transformer later on. The thesis gives a suggestion on how to connect the adjacent transformers M1, M4 and M6 for emergency power.

  • 18.
    Andersson, Carl Fredrik
    University West, Department of Engineering Science.
    50 kVA eller 100 kVA: En teknisk och ekonomisk jämförelse av distributionstransformatorer2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rapporten utreder om distributionstransformatorer med märkeffekten 50 kVA i Vattenfall Eldistribution AB:s elnät kan avskaffas till förmån för märkeffekten 100 kVA. Transformatorer med märkeffekten 50 kVA förekommer vid nedtransformering av spänningen från 22 kV och 11 kV till hushållens huvudspänning 0,4 kV.

    50 kVA-transformatorer skiljer inte särskilt mycket från transformatorer med den högre märkeffekten i fråga om storlek och pris, och de bedöms kunna bytas ut utan större praktiska svårigheter.

    Fördelen med 100 kVA är att de elektriska belastningsförlusterna blir lägre i och med den högre märkeffekten. Dessutom innebär ett byte vissa elkvalitetsförbättringar.

    Nackdelarna med 100 kVA är att de elektriska tomgångsförlusterna är högre och att inköpspriset är högre än för 50 kVA. I övrigt kan kostnaderna likställas för de två alternativen.

    Endast kostnader för aktiva effektförluster berördes i rapporten då de ekonomiska kostnaderna för reaktiva effektförluster kunde försummas för de aktuella transformatorerna.

    För att nå ett svar på frågan om det kan vara lönsamt att avskaffa 50 kVA-transformatorerna studerades fem verkliga fall i Vattenfalls svenska elnät. Dessutom studerades eventuella elkvalitetsvinster med ett byte.

    Svaret blev att inte för något av de fem studerade fallen var det lönsamt med ett byte till 100 kVA-transformator. Rörande elkvalitetsaspekten blev svaret att ett byte visserligen innebär en skillnad men att andra faktorer oftast har större betydelse. Rapportens rekommendation blev att behålla 50 kVA-transformatorn i distributionsnätet. 

  • 19.
    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.

  • 20.
    Andersson, Daniel
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Back, William
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Utvärdering för att främja AMS i relation till planerat SAIDI i Vattenfalls distributionsnät2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vattenfall Eldistribution AB is striving towards maintaining high service reliability for customers in their distribution grid. This ideally implicates that power outages cannot occur from neither unpredictable disturbances, nor as a direct result of planned work. The supervisory authority for the energy markets, The Swedish Energy Markets Inspectorate (Ei) regulates and limits Vattenfall’s revenue based on the key performance indicator (KPI) System Average Interruption Duration Index (SAIDI). To improve SAIDI it is preferential using working methods causing no power outages, where the method of Live Working (AMS) is included.

    Vattenfall’s distribution grid is divided into ten contract areas where one entrepreneur, after leaving a suitable proposal, wins the solicitation process for either of these contract areas’ service agreement. A single entrepreneur (Entrepreneur A) holds all service agreements during this study’s interval (year 2016–2018). There is a high prevalence of compactly built substations today, usually built with fully insulated switchgear, which due to a lack of working clearance and cramped working spaces inhibit the prospect for AMS. A high prevalence of underground cable also inhibits AMS due to difficulties connecting bypassing units.

    A statistical evaluation and compilation of switching orders was conducted and used to determine how AMS is affected by prerequisites and limitations in relation to entrepreneurs, contract areas and substations. The number of established switching orders was 2969 during the year of 2018, of which 17,48 % were established as AMS; which is a decline since year 2016 where 22,86 % of 2616 swiching orders were established as AMS. An increase in investment projects may be a cause for this decline, due to their lower amount of AMS compared to maintenance work. Lowest SAIDI was found in Contract Area 5, 6 and 9, where further studies regarding prerequisites for AMS could be considered, with intention to implement eventual findings in areas with high SAIDI, for instance Contract Area 1 and 4.

    Vattenfall should increase cooperation and diaglogue between and themselves and solicited entrepreneurs with the aim of increasing the number of switching orders established as AMS. Entrepreneurs posess highly valuable knowledge and experience regarding risk identification and future construction possibilities. Goal cards in the service agreement could also contain KPI’s where a certain quota of AMS may entail a suitable bonus. Only 13,75 % av all unique entreprenurs conducted work using AMS year 2018. Vattenfall should research the cause for this decline and evaluate the profitability of substantially subsidizing AMS education and equipment for entrepreneurs, which could be compared to increased costs due to power interruptions from dead working (AUS), like customer notifcations and compensation.

  • 21.
    Andersson, H. Robert H.
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    de Blanche, Andreas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Flipping the Data Center Network: Increasing East-West Capacity Using Existing Hardware2017In: 2017 IEEE 42nd Conference on Local Computer Networks (LCN), 9-12 Oct. 2017, IEEE, 2017, p. 211-214, article id 8109355Conference paper (Refereed)
    Abstract [en]

    In today's datacenters, there is an increasing demand for more network traffic capacity. The majority of the increase in traffic is internal to the datacenter, i.e., it flows between different servers within the datacenter. This category of traffic is often referred to as east-west traffic and traditional hierarchical architectures are not well equipped to handle this type of traffic. Instead, they are better suited for the north-southbound traffic between hosts and the Internet. One suggested solution for this capacity problem is to adopt a folded CLOS topology, also known as spine-leaf, which often relies on software defined network (SDN) controllers to manage traffic. This paper shows that it is possible to implement a spine-leaf network using commodity-ofthe-shelf switches and thus improve the east-west traffic capacity. This can be obtained using low complexity configuration and edgerouting for load balancing, eliminating the need for a centralized SDN controller.

  • 22.
    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.

  • 23.
    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. 

  • 24.
    Andersson, Kristian
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Jason, Evelina
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Beskrivning och vidareutveckling av en modell för beräkning av övertoners fördelning i distributionsnät2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to describe and develop a model used to determine demand permissions regarding power quality on behalf of Vattenfall Distribution. The purpose of the model is to calculate the level of current harmonics allowed for different types of energy subscriptions by studying how harmonics spread in a power grid and how subscribers affect each other. This model needs to be described seeing that the documentation of the original model was lacking. The model also needs to be further developed to increase the flexibility and its ease of use.

    Harmonics are a phenomenon that occurs on the power grid and are generated by non-linear loads like EV-chargers and photovoltaic systems. If the harmonic distortion level is too high, grid connected electronics can experience issues or stop working.

    There are a number of standards, reports and regulations regarding emission rights considering harmonics. This report summarizes three of these as a background to how emissions are regulated today (2018). Two of these papers focus on voltage harmonics levels which is also the case for Vattenfall Distributions governing documents. Vattenfall Distribution needs to develop a new method to determine these current harmonics emission levels, and the model is a part of that process.

    A thorough analysis and mapping of the model were made to produce the documentation for the model. The model was then further developed to allow for more flexibility and could be simplified compared to the original model.

    The original model is considered to fulfil its purpose and therefore no structural changes have been made. The changes that have been made have been implemented to make the model as flexible and user friendly as possible. To help the user to understand the model, a flowchart was made to describe the structure and internal workings of the model.

    The authors believe that a thorough and detailed documentation of the model has been produced and that the model fulfills the purpose of producing representative values to determine demand permissions regarding power quality. The model has been restructured and is now perspicuous and easy to use. However the result from the model is highly dependent of the input data and it's important that it is of good quality.

  • 25.
    Andersson, Markus
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Jonsson, Fredrik
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Säkerhetsanalys av interna IT-säkerheten på ett mellanstort företag2018Independent thesis Basic level (professional degree), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This thesis is about a security analysis of a company's use of IT and their internal network security. The company is a midsized with about 100 employees and half of them use IT in their daily work. The company is active within industrial manufacturing and is located in western Swe-den. They want to develop in IT and are curious about how secure their network is today.

    A review of the layer 2 network security and computers used in the daily work was performed and evaluated. Anonymous interview of employees were made to find out how IT is used at work. A risk analysis was filled in by the responsible employees at the company to get an overview of how they think about risks and vulnerabilities in the use of IT. All this was done to bring recommendations to the company about how they can improve their security compared to what it is today.

    The results from the analysis of the network indicates weaknesses in the layer 2 security and that no security features are currently used to stop attacks from the inside of the net-work. The company has no high demands on the network or the security on the in-side but has given priority to flexibility and physical security.

  • 26.
    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.

  • 27.
    Andersson, Rebecka
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Framtagning av styrdokument för elanläggningsinnehavare2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A control plan is a document that makes the maintenance work more efficient. These documents can for instance be used on a power plant to maintain routines and inspections on the electrical equipment. It is the plant owner's responsibility to ensure that the plant and its associated equipment is checked continuously to ensure the safety of the plant. The frequency of the inspections and what needs to be checked is not mentioned in any laws or regulations. It is thereby up to the owner to decide the ranges and the need of which inspections that are implemented on the plant. This study has been made to simplify the decisions that the owner must take when developing the routine and inspection plans.

    The developed control plan is taken from literary studies and two interviews from two separate companies. Through a comparative study data has been produced that describes what should be performed during a visual inspection and functional controls on a power plant. The study is limited to equipment that is generally occurring in a restricted access area. The produced result is two control documents – one for patrols and one for functional controls. The documents show what type of inspection that should be performed during a control, while the report describes how often these routines should be implemented. The time intervals are produced from a comparison of four companies' routines. Two of the companies has been interviewed while intern documents at two other companies have been reviewed.

    The study has given insight into the inspections that are implemented in a restricted access area and the responsibility that power plant owners have on the plant. The sources are considered relevant to the study and the interviews have been made with persons that possess knowledge in the field of study.

  • 28.
    Andersson, Robin
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Larsson, Jonas
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Jämförelse av riktade reläskyddsfunktioner i impedansjordade nät2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes how different values on a neutral grounding resistor and an uncompensated power distribution network affect the zero sequence current and the zero sequence voltage. If the neutral grounding reactor in the power distribution network is too overcompensated or undercompensated, the directional earth-fault relay may not work. The purpose of this study is to present the advantages and disadvantages of two different earth-fault functions. The two earth-fault functions that will be compared are an admittance-based earth-fault protection and a directional earth-fault protection with angle calculation between the zero sequence current and the zero sequence voltage.

    The capacitive earth-fault currents have increased in the distribution stations because the overhead lines are replaced with underground cables. The capacitive current must be compensated since the capacitance can cause an overcompensated or an undercompensated network. An uncompensated distribution network may cause the zero sequence current and voltage becoming too low so that the earth-fault protections do not detect an earth-fault.

    After the comparison of the two earth-fault functions it can be concluded that there is a minor difference between the both functions. There are some deviations in the test results conducted in a laboratory environment. It is not possible to state which one of the functions that is the most suitable to use in real power distribution networks, since no such tests have been conducted in this study.

    The authors of this thesis have presented some advantages and disadvantages of the two earth-fault functions

  • 29.
    Andersson, Sara
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Mänsklig faktor: hur kan man få den svagaste länken inom IT-säkerhet starkare?2018Independent thesis Basic level (degree of Bachelor), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    In today´s IT environments, the role of the users becomes more important. In 2016 there were 200,000 crimes in Sweden that could be linked to social engineering attacks. These attacks are targeting the users and it is therefore important that users are aware of what they look like. This report is conducted in cooperation with a municipality in Västergötland, Sweden, and investigate four different methods to use when sharing IT information to their users. The methods differ not only in implementation but also in difficulty in the choice of words and expressions. The first method is a document of information taken from the municipality´s intranet. The second is also a document but is rewritten to simplify for the users. The third method is a video presentation and the fourth was made as a lecture with the possibility of interaction between the lecturer and the users. To evaluate these four methods two surveys were conducted. The first survey was performed before the users received IT information to create a baseline. After one and a half month the second survey was made. The surveys are compared to see how much the users remember and which method was most effective. The results indicate that the information on the municipality´s intranet is difficult to understand for the users. The other three methods provide a greater positive change in the user’s questionnaire response, indicating that users need a different form and structure when information is to be provided for them.

  • 30.
    Andersson, Tommy
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Lindell, Erik
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Kartläggning av begränsande faktorer vid fellokalisering med pulsekometod på mellanspänningskablar2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As the medium voltage network cables in Sweden is buried down in the earth, the demand of fault localization expertise increases. To keep downtimes in the network short, the importance of effective fault localization is necessary. This work is aimed to map and visualize limiting factors within fault localization with focus on the TDR -

    Time Domain Reflectometry. This work is a collaboration with Vattenfall Eldistribution AB.

    Problems with fault localization on medium voltage cables with the TDR have been detected. A multiple factors are contributing to this problem. The results of this study show that the cable construction is a significant part in which extent the TDR can be used. The report are also accounting for basic information about construction and types.

    The mapping also illustrates water treeing and how it affects cables in a negative way. Visualization of what causes water treeing and several actions such as triple extrusion, jacket testing and insulation testing is included in the essay. Further information about fault types, cable types, cable generations, instrument types and method types is given. All of them are affecting factors within the area of fault localization.

    Documentation is highly important for a successful fault localization procedure, which is clarified in the report. Besides documentation the cable condition and the influence on it affecting the result of fault localization is stated.

    A number of measuring methods and instruments are available to use when fault localization and testing are occurring. Every instrument has their own advantages and disadvantages. They also have their own respective area of usage. The basic principle of TDR is studied and explained accordingly. The other measuring methods, which are used in fault localization and testing, are shown more generally

  • 31.
    Andlovic, Mihael
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    How real-world IP-distribution affects load balancing2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essay looks at how IP addresses on the last octet are distributed and how they are balanced by different load balancer algorithms. We collected the data from a data center in Sweden to get real data. The IP addresses we collected were used with a load balancer using IP source algorithms. We used 4 different algorithms in different scenarios: the entire IP address, the first 3 octets, and the last octet with and without hash between two to five links/servers. The results were that the efficiency of the algorithm depends on the setup that is being used. Each of these algorithms did not have an even distribution, when comparing between two to five links/servers. The best overall distribution that did not have any weaknesses compared to the other algorithms was Nginx that uses the Bob Jenkins hash algorithm.

  • 32.
    Andréasson, Kim
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Hagberg, Daniel
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Undersökning av iBeaconannonsering via smartphoneapplikation: Objective c och ASP.NET2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project is performed together with the company Sigma in relation with the education Datateknisk Systemutveckling at Högskolan Väst in Trollhättan. The purpose of this project is to examine the new technology iBeacon and study if it is to prefer over simi-lar technologies when developing a system to use for advertisement. To accomplish this, a smartphone application is developed aswell as an administration interface, to be able to perform a user test of the product with a random selection of people.

    The goal with the project is to develop a working product that can be tested and used for the examination of the hypothesis. This report explains how the project is performed and in the end, the result that the user test shows is discussed.

  • 33.
    Antoine, Galluet
    University West, Department of Engineering Science, Division of Automation Systems.
    Kinect to control robot: New ways to interact with robots2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The main goal of the thesis is to create a way to interact with a ABB robot by using a Kinect.The focus will be put on making the robot mimicking the user's arm movement. But otherway like voice control will be investigated.Two main part of the work are developed in this report. The first one is the software aroundthe Kinect to get the body data. The software developed provides the user a visual feedbackon what the Kinect see and allows him to choose what mode he wants to use. Two mainmode are implemented. A mimicking one which makes the robot mimicking the chosen armand a moving object mode which tell the robot to go to the user's position and set the toolas the user hand state.When all the data are gathered, they are sent to the robot using an IP socket and predefinedmessage to give him the desired order.

  • 34.
    Arbo, Thomas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    YubiKey: Utvärdering av tvåfaktorsautentisering2019Independent thesis Basic level (professional degree), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    YubiKey is a small hardware method of authentication, designed to authenticate a user on various network-based platforms such as Google, Dropbox, Facebook and Twitter.

    In the first part of this paper, the underlying technology of the YubiKey, such as the one-time password protocol (OTP) and the Universal 2nd Factor standard, is further described, as well as the approach of the tests to examine how practical and secure the method itself is, but also examines its ease of use. These tests were performed on the platforms Google Account, Facebook, Dropbox and Twitter platforms. The YubiKey is also compared to other methods in relation to the phishing, malware, password guessing, man-in-the-middle and shoulder surfing attacks.

    The purpose of the comparison was to see if YubiKey protects against these attacks, compared to other methods, thus investigating its security. A later part presents the results of the tests, but also compares YubiKey with other methods in the market, and examines the recovery of a stolen och lost Yubikey. These tests show the simplicity of the method, its ease of use and how practical the method is.

    The comparison clearly shows that YubiKey is a very safe method, which resists common threats to the user side. The simulation of the recovery process further attests to its ease of use and ease of handling, even with lost or stolen key.

  • 35. Arezoomande, Daniel
    Anslutning av två vindkraftverk till befintligt nät2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis was conducted at University West in Trollhättan and Kungälv Energi AB in Kungälv. Being owner of an electrical grid, Kungälv Energi AB has the responsibility to check if the electrical grid needs to be reinforced when connecting new electricity generation facilities such as two new wind turbines. This thesis mission is to examine how the voltage quality might be affected by the connection of the wind turbines and give suggestions on how to solve eventual problems. Several alternatives will be examined for how the cables between the wind turbines and the power grid should be placed. One cost calculation will be presented. The voltage quality calculations are done through the guidelines from AMP, Anslutning av Mindre Produktionsanläggningar. Because the provider of the wind turbines has yet to be decided, necessary data has been taken from the previously connected wind turbine in Skåreby, "Vindrosen". The cost calculations are done with the help of EBR, ElByggnadsRationalisering. The cable dimension alternatives that are presented are based on costs and long term planning. These dimensions are 95mm2 and 240 (underground transmission line)- alt. 241mm2 (overhead transmission line). The thesis also includes suggestions for alternative dimensioning of the currently placed power grid at the point of interconnection for the wind turbines. All presented alternatives of the dimensioning for the cables are solely 24kV in accordance with the rest of the power grid to avoid unnecessarily high costs. It is recommended that Kungälv Energi AB does not connect the wind turbines before more thorough calculations are made in conjunction with eventual harmonic distortion measurements. This is because the equations AMP refers to are deemed imprecise due to some parameters such as cable capacitance have not been taken into consideration. It is recommended that, during the negotiations of the new wind turbines, Kungälv Energi AB limits the maximum current harmonic distortions that the wind turbine produces.

  • 36.
    Aronsson, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Bäversjö, Jonathan
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Undersökning av gratis WiFi i Göteborg2014Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This report examines a number of free WiFi-hotspots that are offered by various companies in central Gothenburg and how they compare to the mobile networks. Traffic, capacity, channel frequencies, signal strength and acceptable use policies were all analyzed and verified.

    The readings showed that the networks were generally not utilized to their full capacity, a probable cause might be the distribution of mobile networks and that channel distribution was with a few exceptions allocated correctly according to 802.11 standards. Acceptable use policies on the networks were implemented by the larger chains but not by the smaller companies

  • 37.
    Atar, Mohammad
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Förstudie till fältbusslaboration för elkraftstillämpningar2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes how to develop a fieldbus lab. The lab will be part of the course Data communications with electric power applications (course code DML200) at University West. The goal and purpose of this lab will be to allow students learn how to set up, commission and troubleshoot equipment. In this context, the course also directed towards electric power technology and it is important for the Bachelor programme in electrical engineering with specialization in power electric because the course is included in the program.

    The work was aimed at developing suitable equipment which must include the appropriate number of protection relays and the necessary components for communication via ProfiBus such as PLC controllers, I/O-module, the Operation Panel. Different companies where asked about the prices of the components and a collection of quotations was made.

    The response from three out of five different companies indicated that ProfiBus is an old system. Everyone wondered why ProfiBus was chosen as a communications system over other system such as Ethernet with ModBus. According to these companies ProfiBus is an old communication system and it is expensive. It could save some money if the problem was solved with ethernet with ModBus because of the availability of the manufacturers. Finally the lab idea was illustrated with a wiring diagram.

  • 38.
    Augustsson,, Jimmy
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Printz, Kristoffer
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Svensson, Erik
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Larmanalys för Vattenfall Vattenkrafts produktionsanläggningar längs Göta Älv2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vattenfall Vattenkraft AB owns 57 large scale hydro power plants in Sweden with installed power exceeding 10 MW. The study relates to four of the plants located along Göta river. This report analyzes incidents and the related remedial actions that have occurred during the period 2014 – 2017 as well as the alarm and control systems with the aim to identify potential improvements. The incidents are categorized by error, what actions have been undertaken to correct the issue, plant and season. The incidents have predominately originated in the turbine and generator facilities and have been caused by abnormal levels or temperatures. During summer and winter time, this is mainly due to variation in temperature and flow in the river. The four plants have caused a similar amount of alarms, which is interesting as there is a large variation in age. The analysis does not identify any reoccurring issues which were previously unknown to the company, but the authors recommends that an investigation is conducted to assess if eel screens should be installed for the cooling pumps of Lilla Edet. The alarms are generated in the plants and are sent to the control facility in Bispgården near Sundsvall, where the operator calls the local engineer on duty in Trollhättan. The engineer subsequently goes to the plant to access detailed information on the incidents from the local computers. This report examines the possibility to provide the engineer on duty with detailed information from the plant computer via VPN. This would be possible to implement but would require a detailed assessment of the security implications. The status of the alarm system have also been assessed as it have been modified and extended retroactively, and there is currently no comprehensive overview. The conclusion is that a review of the list of incident codes and their priority is recommended.

  • 39.
    Augustsson, Per
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Mansori, Farsad
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Skapande av dynamiskt modellnät för analys av lasters beteenden vid nätstörningar2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor’s thesis is carried out on behalf of Vattenfall Eldistribution AB in Trollhättan. This work aims to make modelling of power grids for simulations, of load behaviour during perturbations, in PSS/E more effective. Modelling will be made more effective by means of programming, using the programming language Python, and also by allowing certain assumptions to be made about the grid. The idea for this work arose from a certain case, during which Vattenfall was tasked with investigating why voltage levels near an industry would not recover after a short circuit, on the transmission line feeding the industry, was cleared. Investigations demanded simulations of the disturbance to be carried out in PSS/E, to describe what had happened. To enable simulation and to make it representative, the grid and its components must be adequately modelled. Svenska kraftnät has the data nessecary for such modelling, but it is inaccessible due to confidentiality. Due to the data being confidential extensive work with modelling was nessecary. Early simulations were based on the idea that some parts of the grid can be modelled using only simplified models, and with typical, or default, values. This thesis uses that hypothesis in the programming code. The low voltage after these perturbations were caused by motors, more specifically induction motors, drawing high currents from the grid during reacceleration when the voltage starts to recover after the perturbation. This high, and mostly reactive, current causes significant voltage drops across the lines and transformers, in turn causing other motors to draw more current and further lowering voltage. The programming code, called a script, developed during this work allows the user to quickly create dynamic model data to use when conducting simulations of the dynamic behaviour of this type of loads. Modelling of the generators is done quickly thanks to the assumption that generators are located far enough away that they are barely affected by the studied disturbance. They are, for this reason, modelled using typical values. Through a graphical interface, the user then select which loads to model. For each load model, the distribution across different types of loads is specified by the user. Finally, protection relays are modelled to enable current monitoring. The script has been tested by comparisons to a reference network model created by Vattenfall. The comparisons show minor deviation between the script and the reference. This could be because the script uses default values and models less components than the reference.

  • 40.
    Augustsson, Svante
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Human and Robot Interaction basedon safety zones in a shared work environment2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work explores the possibility to increase the automation along a production line by introducing robots without reducing the safety of the operator. The introduction of a robot to a workstation often demands a redesign of the workstation and traditionally the introduction of physical safety solutions that can limit the access to the work area and object on the production line. This work aims to find a general solution that can be used not only in the construction industry, but also in other types of industries to allow for an increased Human and Robot Interaction (HRI) without physical safety solution. A concept solution of a dynamic and flexible robot cell is presented to allow for HRI based on safety zones in a shared work environment. The concepts are based on one robot and the usage of a 3D camera system allowing for the design of virtual safety zones, used to control the HRI. When an operator approaches the robots work area and triggers a safety zone the robot stops its work and moves away from the operator. Based on the safety requirements and triggered zones the robot will continue to work in a new area or wait until the operator leaves the work area and then continue with the interrupted work task. This will allow the operator and the robot to work together, where the operator location controls the robots workspace. Testing and validation of the presented concept showed that the wanted functionality could be obtained. It also showed limitations to the equipment and the system used during tests and raised additional aspects of the safety for HRI. Of the detected limitations the most crucial when looking at up-time for the production line, is the camera system need of a relatively dust free environment, good and constant lighting. For the safety of the system the limitation lies in the size and placing of the safety zones in combination with the disturbance from  surrounding equipment. The presented concept has proven to work, and can be applied not only for the construction industry but for all industries with manufacturing alongside production lines with large components.

  • 41.
    Augustsson, Svante
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Gustavsson Christiernin, Linn
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation Systems.
    Human and robot interaction based on safety zones in a shared work environment2014In: HRI '14: Proceedings of the 2014 ACM/IEEE international conference on Human-robot interaction, New York: Association for Computing Machinery (ACM), 2014, p. 118-119Conference paper (Refereed)
    Abstract [en]

    In this paper, early work on how to implement flexible safety zones is presented. In the case study an industrial robot cell emulates the environment at a wall construction site, with a robot performing nailing routines. Tests are performed with humans entering the safety zones of a SafetyEye system. The zone violation is detected, and new warning zones initiated. The robot retracts but continues its work tasks with reduced speed and within a safe distance of the human operator. Interaction is achieved through simultaneous work on the same work piece and the warning zones can be initiated and adjusted in a flexible way.

  • 42.
    Augustsson, Svante
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Olsson, Jonas
    University West, Department of Engineering Science, Division of Manufacturing Processes. University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Gustavsson Christiernin, Linn
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    How to Transfer Information Between Collaborating Human Operators and Industrial Robots in an Assembly2014In: Proceedings the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational, ACM Publications, 2014, p. 286-294Conference paper (Refereed)
    Abstract [en]

    Flexible human-robot industrial coproduction will be important in many small and middle-sized companies in the future. One of the major challenges in a flexible robot cell is how to transfer information between the human and the robot with help of existing and safety approved equipment. In this paper a case study will be presented where the first half focus on data transfer to the robot communicating the human's position and movements forcing the robot to respond to the triggers. The second half focuses on how to visualize information about the settings and assembly order to the human. The outcome was successful and flexible, efficient coproduction could be achieved but also a number of new challenges were found.

  • 43.
    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.

  • 44.
    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.

  • 45.
    Barrvik, Erik
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Hagman, Alma
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Undersökning av orsaker till komponenthaverier i uppsamlingsnätet till vindkraftparkerna Vettåsen och Mårtensklack2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate why the cable terminations and power transformers in Wallenstam’s wind power plants, at Vettåsen and Mårkensklack, have broken down six times since December 2011, which was when they were first put into service.

    Power readings have been taken but there are no records for the times of the failures, which make it difficult to specify the failure source. However, from the readings that have been taken, there is nothing to indicate a cause for the failures. The transients are small and the proportions of harmonics are low. Since the instruments used to take the readings will only record up to 50th harmonics, a possible cause of failure could be high harmonics. Thunder storms, and cutovers in the power grid can probably be dismissed as sources of failure as well as manufacturing and installation faults.

    One proposal to remedy cable termination failures is to use geometric terminations which have been developed for grids with harmonics. Also, to reduce transients in the systems, surge arresters could be installed at the Vettåsen and Mårtensklack stations to ensure that the power quality can be monitored. The power readings need to be continued to specify the failure source

  • 46.
    Bassem Yehia, Khaled
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Abdowod,, Vahab
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Analys av indikatorerna AIT, AIF, SAIDI och SAIFI i lokalnätet2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Swedish Energy Markets Inspectorate (EI) is a regulatory authority for electricity, district heating and natural gas, where one of their tasks is to control the company's power distribution quality. A good electrical delivery reliability is determined on the basis of EI:s regulations and general advice in the publication EIFS 2013:1.

    Every year, the power distribution companies reports data to EI of the disturbances they have had in their networks, which is used to measure and analyse the electrical delivery reliability in the Swedish electricity grid. EI uses established indicators that describe the electrical delivery reliability of the distribution networks in Sweden. The indicators used today are named SAIDI and SAIFI, which are customer-weighted indices that describe the average interruption duration and the average interruption frequency for a specific network.

    In the beginning of 2019, EI will consider introducing two indicators to replace the current SAIDI and SAIFI indices, the indicators are being defined as AIT and AIF. According to EI, these indicators will be better than SAIDI and SAIFI as they take into consideration the customer's expected power consumption during the power outage.

    The purpose of this report is to investigate how the new indicators AIT and AIF affects the delivery reliability indicators in GENAB:s network, where these indicators are exercised on different types of networks and then compared. How the network can be made more efficient in the future by means of automation in the network is investigated based on the results on the indicators.

    From the results and investigations, it can be concluded that the transition to AIT and AIF will result in an increase of the indicator´s interruption time and the number of interruptions for customers per year in GENAB:s network.

  • 47.
    Beissinger Bart, Andres
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Soto Vallejos, Nicolas
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Beredning av kabelnät i området Sjöhaga - Lerdala Gård2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis describes a preparation work for Ellevio AB. The preparation work is supposed to rebuild the power grid in Sjöhaga - Lerdala in Skövde municipality with the aim to weatherproofing the local area network and increase the reliability. The project concerns all work on preparation such as contact with authorities and landowners involved in the project, in order to agree on where the new cables can be built. Field visits were conducted continuously during the project for an overview of the area and to plan possible cable stretches, as well as the best possible location for the network stations in agreement with the landowners. The preparation of the underground cable is carried out in four parts, part one is Sjöhaga - Melldala, part two is Melldala - Karlsfors, part three is Karlsfors - Dämman and part four is Dämman – Lerdala Farm. Part one will have a serial satellite network station with a 200kVA transformer and no local network preparation will take place at this stage. In part two Karlsfors will keep its current local distribution network and network station, part three will have an ELIT3 network station fitted with a 100kVA transformer. For part four, there will be an ELIT3 network station with 100kVA transformer and three cable cabinets. In addition to these parts, the possibility for a redundancy feeding between Karlsfors - Yttersöra was investigated. However, when this was perceived as not possible due to the environmental conditions, it was decided, on the recommendation of a supervisor at PSN Kraftkonsult, to be placed between Dämman - Björnsäter with a overhead cable on existing poles. The cost of the renewal amounts to 2.6 million SEK and 449 thousand SEK for the redundancy from Dämman to Björnsäter. Network stations are positioned in Melldala, Dämman and Lerdala Farm which also has three cable cabinets. The total cable length of the HV-system is 6.5 km and the LV-system is 1.70 km.

  • 48.
    Ben Mabrouk, Amina
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Maalallah, Mustafa
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Utvecklingsarbete gällande metoder för beräkning av bortkopplad last vid automatisk förbrukningsfrånkoppling2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vattenfall Eldistribution wishes to compile in real time which load that is available for disconnection via AFK (Load shedding) to avoid network collapse. This is done by implementing methods on Vattenfall's operating system to get an estimation of the load available for disconnection when AFK is activated.

    The purpose of the work is to create a summarized measurement value which, in real time, indicates how much load is available for disconnection with AFK in Vattenfall's network. This is to ensure that Vattenfall Eldistribution meets the requirements of SvKFS 2012: 1 during all hours of the year.

    The work is divided into two parts; one part to produce useful methods for obtaining the desired measurement values and another part for the implementation that has taken place in Vattenfall's operating system. These goals have been achieved by carrying out analyses and calculations of approximately one hundred stations containing AFK equipment that are located in three different zones in the electricity area SE3.

    Results are presented through a final overview, which is a fictitious picture of how it looks after implementation based on the methods developed in Vattenfall's operating system. In the resulting overview image, each station containing the AFK equipment is presented with a sum of the available active power for disconnection and each station is located under respective disconnection step.

  • 49.
    Benages Montolío, Sergio
    University West, Department of Engineering Science, Division of Automation Systems.
    Robot Behaviour Monitoring in Friction Stir Welding2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Friction Stir Welding is a solid state join process in which the heat need is produced by the friction of a tool on the work pieces. The tool rotates on the surface and also applies a force against it to create the needed friction. This technology does not use any consumable and does not produce any gas, which makes it cost effective, save for the operators and clean.

    The equipment used for this technology has been changing within the years. Milling machines were adapted to it at the beginning. After, specific machines for friction stir welding were developed, providing higher down force and control systems. Nevertheless, the lack of flexibility of machines made industrial robots became an alternative. Robots have limitations in terms of stiffness. But, they can be used to weld complex geometries and they can be used in large scale applications due to their flexibility and low cost.

    This project studies the process from the robot behaviour perspective. The main objective is to achieve a better understanding of the process to contribute to the continuous development of robotic FSW. An acquisition system was developed to monitor different signals from the robot such as, forces, torque, path deviation, and vibrations. The data acquisition system developed and mounted at PTC was tested and its limitations were examined. The developed system has been used for conducting different experiments: The differences between the robot system and a system based on a FSW machine situated at TWI were studied; and, in addition, the behaviour of the robot under different welding parameters was investigated.

  • 50.
    Bengtsson, Robert
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Claesson, Rickard
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Att designa ett kostnadseffektivt nätverk för det lilla företaget2018Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This paper goes through the process of designing a corporate network from scratch. The work clarifies some concepts in network design, how a simple requirement specification can look and how it is used in the process of creating a network that meets the customer's needs.

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