Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Modellıng And Sımulatıon Of A Doubly Fed Inductıon Generator-based Wındturbıne Under Symmetrıcal Voltage Fault
    (2023) Çiçek, Elif Dilara; Akkurt, Gülden Gökçen; Altun, Kerem
    When wind turbines, which convert wind energy, one of the renewable energy sources, into electrical energy, are connected to the electrical grid, it is of great importance to maintain grid stability. However, the variable nature of wind can pose certain challenges to system stability in wind turbine grid integration. Regulations in different countries require wind turbines to continue contributing to the grid in the event of a fault. In this thesis, the process of converting wind energy into electrical energy through a specific generator is described, and the behaviour of the turbine is simulated in the event of a symmetrical voltage fault. This thesis aims to develop a simulation model for a variable-speed doubly fed asynchronous generator-based (Dfig) wind turbine with a partially scaled frequency converter control using the field-oriented vector control method and to investigate its grid contribution ability under different conditions. The aim was to ensure torque control on the generator side and grid-side control. After the completion of the control system, the turbine's grid contribution ability was examined under short-term faults, and it has been shown that the system continues to contribute to the grid after the voltage drop. The modelling was performed using the Matlab / Simulink program, and the results were shared. In the last part of the thesis, the effect of a symmetrical fault on the rotor current is analysed by the Monte Carlo method.
  • Master Thesis
    Effects of Electrical Dynamic Response of Doubly Fed Induction Generator Type Wind Turbines on Their Mechanical Systems During Single and Multiple Faults
    (2023) Coşgun, Mert; Karadeniz, Ziya Haktan; Altın, Müfit
    In the early stages of wind turbine technology, the focus was on the separate development of mechanical and electrical systems and research was carried out only in these areas. Today's modern wind turbine designs, which have reached megawatt sizes, continue to be more cost-effective and dependable for countries to achieve their renewable energy targets. In this direction, wind turbine research and development processes have now started to focus on both mechanical and electrical systems and their subsystem interactions. In this thesis study, it is aimed to investigate the effects of the response of electrical control systems on towers components during grid faults. A doubly fed induction generator is used for power generation and power systems including converters and control systems are modelled in MATLAB/Simulink. Simulations were designed in Simulink to test the grid-connected wind turbine model and the Fault Ride Through condition that causes voltage drops in the grid connection lines; the response of the control system and electromagnetic torque output in the relevant case were sent to the mechanical system analysis tool Horizonal Axis Wind Turbine Simulation Code 2 to observe the effects on the mechanical system. In Horizonal Axis Wind Turbine Simulation Code 2, the interaction of the main bodies against forces and limits is analyzed and the results are reported graphically. The state of the system without fault and data with the faults are analyzed comparatively. It has been observed that the reactions of the electrical power systems during grid failure influence the mechanical systems.
  • Master Thesis
    An Experimental Investigation of the Parameters To Classify Wind Sites
    (Izmir Institute of Technology, 2002) Türkeli, Hayri Murat; Özerdem, Barış
    Wind data measured on Izmir Institute of Technology campus area have been used to evaluate the wind power potential on this location. Measured data set and its evaluation showed that Izmir Institute of Technology campus area has a considerable wind potential. Mean wind speeds have been found 7.03 m/s at 10 m height and 8.14 m/s at 30 m height. The prevailing wind direction has also been found as north direction. WAsP and WindPRO softwares have been used to evaluate the wind statistics and energy calculations. Wind turbines with 600 kW and 1500 kW nominal power have been fitted as the most efficient ones. Suitable sites were selected according to created average wind speed map and wind energy maps of campus area.Fourty seven 600 kW turbines with a total capacity of 28.2 MW and twenty six 1500kW turbines with a total capacity of 39 MW were located on the selected sites separately. The annual energy productions of the 600 kW and 1500 kW wind turbines have been calculated as respectively 100.3 GWh/year and 122.4 GWh/year.