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  • 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.

  • Eriksson, Christoffer
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Framtagning av tillförlitlighetsdata för ställverksapparater i Vattenfalls regionnät2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Higher demands are placed on network operators regarding the delivery quality. Part of the decision-making in constructions or renovations is to estimate costs for any possible fault on the network. To make these calculations, it is required that the correct input data is available. The relevant data shows what can be expected of a component, how reliable the devices are. This report focused on what data is available to calculate a result with reliable fault frequency for switchgear devices from different sources. The research only includes the transmission network and focus has been on finding reliable sources where the results has been documented, which presents the opportunity to make an assessment of the reliability. Cigré has previously conducted the most comprehensive report and collected data from around the world. Electrical companies from 28 countries contributed which was analyzed and summarized in multiple reports. Other sources reviewed for this research are ENTSO-E and Nordel, who for several years has compiled statistics from the Nordic countries in annual reports. Something that attracted attention in the work is that Vattenfall has performed an incorrect reporting of transformer fault in recent years. This results in multiple failure rates of Nordel and ENTSO-E is not useful, it should be reviewed by Vattenfall to contribute to this collection statistics that are useful for all grid companies. In this research, recommended error rates are presented based on the collected statistics. The values presented are for power transformers, circuit breakers, disconnectors, earthing switches and instrument transformers. The voltage levels included varies for the different components.

  • Roshag, Alexander
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Bergfelt, Erik
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Energikartläggning av Renovas anläggning i Sävenäs, Göteborg2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Renova had to perform an energy audit on their waste-to-energy plant at Sävenäs. The purpose of this thesis was to assist in the full energy audit and come up with proposals on how to make electric energy savings. Only electric energy was studied during this thesis.

    Energy measurements were performed with two instruments from Chauvin Arnoux. Instruments used are called CA 8335 and CA PEL103. Objects that were measured in the plant were heaters as well as fans and pumps driven by motors. The parts of the plant that were measured during the work was Boiler 5 and the common loads that are used for all boilers. The plant’s operating conditions rarely change and therefore it was decided to make daily measurements.

    The project manager decided that at least 80 percent of each switchgears active power should be measured to get an acceptable level in the energy audit. The method used during the measurements was to start on the largest power consumer and then work down to the smallest power consumer. The measurements took place in the same switchgear until 80 percent of the switchgears active power was measured. Afterwards the measurements continued in a new switchgear. Previous data were analyzed while the new measurements went on. The analysis was made in order to find possible proposals on how to make electrical energy savings.

    During this work 2576.6 kW were measured out of totally 9500 kW. This measured power corresponds to 27.1 percent of the plant’s total electric energy consumption. 1097.5 kW was consumed by pumps, 957.7 kW was consumed by fans, 90 kW was consumed by heaters and 431.4 kW was consumed by other objects not included in any of the previously mentioned categories.

    One proposal was presented for object MFL537-05. The proposal was to use an frequency converter to change the objects operating pattern. The change in the objects operating pattern would save approximately 50 MWh/year and 18 000 SEK/year, which equals 0.07 percent of the plants total energy consumption. The plants total energy consumption is 74 200 MWh/year.

  • Oskarsson, Emil
    et al.
    University West, Department of Health Sciences, Section for nursing - undergraduate level.
    Pettersson, Erik
    University West, Department of Health Sciences, Section for nursing - undergraduate level.
    Psykisk ohälsa hos människor på flykt: En litteraturöversikt2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: There has been an increasing prevalence of mental illness among Swedes; in addition a lot more people have fled their home countries due to war and disaster. With them they carried traumatic experiences. What have these effects and occurrences had on their mental status? Aim: This study aims to investigate the prevalence and experience of mental illness among fleeing people. Method: A literature overview was performed to gather and analyse data from both qualitative and quantitative studies. A search for prevalence in quantitative data was used. Prevalence of mental illness is first presented in a compilation and then three themes with seven subthemes describing similarities and differences emerged in the analysis of qualitative and quantitative studies. Results: Prevalence of mental illness was more common among displaced people than the non-displaced with depression, anxiety and posttraumatic stress as the most common diagnosis. Traumatic experiences were also a factor that could hinder the individuals from adopt in the new country. It also showed that there were effects that fortified the mental illness as well as their own defence mechanisms. However, the individuals also experienced support from people with similar experience as well as people in the society they now belong to. They also felt that they wanted to be acclimatized into their new country in order to create a new life. Conclusions: The nurse's role is of importance to create an interpersonal relationship and thus provide safety and trustworthiness to give patients’, persons who have fled, understanding and confidence in health care regarding their mental health.

  • Johansson, Anders
    University West, Department of Engineering Science, Research Enviroment Production Technology West. Global Industrial Development, Scania CV AB, Södertälje.
    Money talks while volume and value should run the show: An evaluation of financial parameters for decision making duringmanufacturing system acquisition2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Market economic values have for the last decades been given an increasing role with the establishment of financial institutes and global organisations with a capitalistic focus as a consequence. As a counter reaction, the concept of sustainable development has emerged complementing the economic focus with environmental and social aspects. However, there are still challenges on how to make balanced decisions based on all three view points and consequently the decision makers still primarily reside to the established tangible financial data. Within the industrial setting there is no difference. The manufacturing system design is based on multiple criteria and requirements, but commonly the final investment decision is primarily based on what can be financially justified. Longterm solutions probably lies in combining the tangible economy with the less tangible soft values that cannot be valued in monetary means. Therefore, to find this sweet spot, the purpose of this research is to in-depth investigate the world of economy, but from an engineers' point of view. A financial analysis is done to understand the economical components and how these are related to the manufacturing system. Furthermore, to connect cost with contributed value of the manufacturing system, a holistic business value chain analysis is done to ensure that less tangible aspects can be understood and utilised. The result of this research, highlights for example that sales volume has a larger impact on the manufacturing profitability, than that of the initial investment cost. Therefore, manufacturing systems should also be evaluated on the bases of how well it can meet the volatility in market demands. Another result presented is a portfolio of new graphical representation used as a support tool for investment decisions. Furthermore, to be able to invest in manufacturing systems that contribute to a more competitive company, the wider business value with manufacturing is discussed.