Ämneskategori: Elkraftteknik

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1. Investigation of Cloud-Effects on Voltage Stability of Distribution Grids with Large Amount of Solar Photovoltaics
   Cirjaleanu, Valeriu
   Examensarbete på avancerad nivå, 2017 (MSc - Electric power engineering)
   The Photovoltaic (PV) energy is becoming more and more popular nowadays due to both the awareness of people about environmental concerns and the governmental support schemes which makes it more accessible for the potential PV owners to install PV systems at the residential level. However, the integration of large amount of PV systems at the residential level...
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2. System-Wide Evaluation of Inertia Support Potentials from Wind Farms
   Jung, Paul
   Examensarbete på avancerad nivå, 2017 (Masterarbete)
   In order to limit anthropogenic climate change as well as the dependency on fossilfuels, the wind power generation is rising world wide. Since modern wind turbinesare usually variable speed wind turbines, which are connected to the grid via aconverter, this causes a decrease in grid coupled inertia. Because decreased inertiacauses faster and greater frequenc...
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3. Development of an energy management model for Chalmers’ microgrid: Application for cost-benefit analysis of battery energy storage
   Göransson, Martin; Larsson, Niklas
   Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
   A microgrid is a portion of a larger grid which can be operated independently, thus itis seen as a single entity from the main grid which can be operated in grid connectedor island mode. The microgrid consists of distributed energy resources (DER), energystorage system (ESS) and loads which can be controllable. This thesis is apre-study regarding Chalmers’ g...
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4. Feasibility study of a sustainable power system for health facilities - Case study of Kolandoto hospital-Tanzania
   Kalisa Twizeyimana, Eric; Ndisanga, Therance
   Examensarbete på avancerad nivå, 2016 (MSc - Sustainable Energy Systems)
   Solar photovoltaic is strongly proven for cutting down greenhouse gases emissionsand environmental destruction problems that the world is facing today due to theuse of non-renewable energy sources. Tanzania considered in this study is also experiencingthese challenges with imbalance and unreliable electrical power supplymore precisely in health facilities. T...
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5. Grid loss reduction with Demand response
   Andersson, Niklas
   Examensarbete på avancerad nivå, 2016 (MSc - Sustainable Energy Systems)
   In order to achieve more efficient use of the electricity grid, the Swedish market inspectorate has introduced an incentive for the grid companies in Sweden to reduce electricity grid losses and reduce peak demand. The incentive provides an increase in the revenue cap (the maximum allowed income) for the grid companies. One way to achieve reduced losses is t...
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6. Sub-synchronous controller interaction (SSCI) of series-compensated DFIG wind farms
   Elgaali, Ahmed
   Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
   One of the problems faced by the integration of large renewable energy sources -such as wind turbines- is that often the load centres are very far from the productioncentres. This forces the use of series capacitor compensation in order to increasethe power transfer and the transient stability limits. The presence of series compensationintroduces resonance i...
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7. Feasibility and Challenges in Microgrids for Marine Vessels
   Wang, Xue
   Examensarbete på avancerad nivå, 2016 (Masterarbete)
   Due to the development of distributed generation (DG) and power management technologies, an islanded marine power system, namely microgrid in marine, becomes a promising option for marine power systems and gains an increase in research interest. Microgrid solution provides integration of renewables, energy storage systems and existing generation units. It en...
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8. Cell Level Power Electronics for Better Battery Management System
   Gorantla Narayana Murthy, Sri Vishnu
   Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
   In this master thesis, a comparison between two types of battery packs for ElectricVehicles (EVs) is made. Pack 1 is a conventional cells battery pack where all thecells are connected in series. Pack 2 is an autonomous cells battery pack whosecells are equipped with individual micro DC-DC converters. Pack 1 is comparedagainst Pack 2 for energy output (kWh),...
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9. Cell characterization and modeling of lithium ion batteries
   Strängberg, Victor
   Examensarbete på grundnivå, 2016 (Elektroteknik, högskoleingenjör (180 hp))
   The purpose with this thesis was to estimate the parameters from one of the electrical equivalent circuits that are used for batteries. Two different batteries with different chemistries have been tested. First measurements at different frequencies have been performed to obtain the impedance at a specific frequency. When the impedance is known, the informati...
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10. Evaluation of Methods for Improving and Testing Power System Stabilizers in Reciprocating Engines
    Halyes, Erdi; Raja, Gayathri
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    The small-signal stability of a power system is enhanced by damping system oscillationsby power system stabiliser (PSS). In synchronous generators driven byreciprocating engines there are torque variations which in turn disturb the PSSoperation. This thesis investigated the current methods used to design PSS for reciprocatingengines and also the use of #12;l...
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11. Distribuerad genererings påverkan på dimensionering och planering av lågspänningsnätet i Halmstad
    Tahir, Soran
    Examensarbete på grundnivå, 2016 (Elektroingenjör (180 hp))
    A study about how micro production from photovoltaic cells affects a low voltage network was conducted at Halmstad Energi och Miljö Nät AB, where a fictive residential area working as a test network was built up in the programme dpPower with help of theory collection and the knowledgeof planning and power engineers at Halmstad Energi och Miljö Nät AB. The fi...
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12. Utredning av hållbar elnätstruktur för tät blandstad
    Lind, Philip; Malmqvist, Joakim
    Examensarbete på grundnivå, 2016 (Elektroingenjör (180 hp))
    When building a new area in a modern dense city with a mix of residential and commercial buildings, it can be difficult to use the traditional type of distribution grid with a large part of low voltage level for various reasons. The main purpose is therefore to investigate under what circumstances it is more beneficial to build the power grid with mainly med...
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13. Development of a system protection model against voltage collapse in PSS/E
    Stenberg, David; Åkesson, Joakim
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    This thesis investigates voltage instability leading to voltage collapse in PSS/E andhow such scenario can be prevented by the use of a system protection model whichhas been proposed and developed in this thesis. The model sees the system as awhole and can initiate a system protection response based on a voltage stabilityindicator in parallel with signals fr...
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14. Analysis of Force and Torque Harmonic Spectrum in an Induction Machine for Automotive NVH Purposes
    Garcia De Madinabeita, Inigo
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    Currently, hybrid and fully electric vehicles are being developed in a great varietyregarding topology, power and range. This requires a new methodology for NVH(Noise Vibration and Harshness) evaluation of potential problems early in the designphase. This methodology requires reliable simulation approaches for hybrid andelectric drivetrains, concerning the w...
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15. Modelling of Modular Multilevel Converter Using Input Admittance Approach
    Abun, Adulis
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    With increasing Distributed Energy Resources (DER) penetration and increasedHigh Voltage Direct Current (HVDC) applications, Modular Multilevel Converter(MMC) is becoming an integral part of the power system due to its advantages interms of scalability, harmonic performance and efficiency. One of the most challengingtopics as with regard to MMC lies in its m...
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16. Strategy for designing solar powered UPS systems - in hospitals in Eastern Africa
    Skilbred, Martin; Rohlén, Simon
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    In Eastern Africa a stable supply of electricity from the grid cannot be taken forgranted. It is therefore important to investigate possibilities on how to improvethe supply for areas of the society that suffers the most from these flaws. A poweroutage during an ongoing operation at a hospital could in the worst case be fatalfor the patient and therefore hos...
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17. Electric Power System Ancillary Services of Electrofuel Production
    Asadian, Haifa
    Examensarbete på avancerad nivå, 2016 (MSc - Sustainable Energy Systems)
    In the future European energy system, with high penetrations of uctuatingrenewable energy generation along with the increased demand for rapidreduction of fossil-based energy and the growing disinclination towards andphase-out of nuclear-based power, the development of reliable technologies,which can cope with the system's rapidly altering pro#12;le becomes...
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18. Commutation Failure Prevention for HVDC Improvement in algorithm for commutation failure prevention in LCC HVDC
    Oketch, Innocent
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    Line commutated HVDC systems are widely used due to their high power ratings.However, one of the disadvantages of such HVDC systems is the high risk of commutationfailures when AC disturbances arise. These failures normally develop inthe inverter station. When failed commutation occurs, the LCC HVDC system isgreatly disturbed resulting in loss of power trans...
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19. Mild Hybrid Electro-Thermal Battery Modelling
    Biswas, Akik; Yao, Xuming
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    In this thesis an electro-thermal battery pack model has been developed for a48 V Mild Hybrid vehicle application to predict the pack temperature under differentloading cases which have been verified with experiments.Both the joule and the entropic heat play significant roles in the total heat generationprocess. Furthermore, the entropic heat can be both end...
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20. LCC Based Multi-Terminal HVDC Operation without Telecommunication
    Navakauskas, Rytis
    Examensarbete på avancerad nivå, 2016 (MSc - Electric power engineering)
    A continuous increase in power demand, especially in the developing countries, andrapid growth of renewable energy source integration resulted into a rebirth of HighVoltage Direct Current (HVDC) transmissions in the last two decades. Nowadays, aLine-Commutated Converter (LCC) HVDC is a dominant technology for high powertransmission over long distances. Typic...
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