Control of doubly fed induction generator based vari̇able speed wi̇nd turbi̇nes

In recent time, because of growing energy demand and extinction of fossil fuels which will supply this demand also environmental problems that fossil fuels cause, the trend to renewable energy sources is increasing. One of the renewable energy sources is wind energy. Together with the developing electrical and power electronics systems, wind turbine installation are increased all over the world especially in last years. The development of the world has affected our country evenly, wind turbine installation are increased and the electrical power capacity obtained from kinetic energy of wind is increasingly raised its percentage at the total installed electrical power capacity. Wind turbines, are classified as fixed speed and variable speed wind turbines depending on wind speed. Because many advantages as power generation in wide range of speed and high efficiency due to variable wind speed, the use of variable speed wind turbines gradually increase. Generally, synchronous generators or doubly fed induction generators are used in variable speed wind turbines. The structure and control of doubly fed induction generator based variable speed wind turbines is studied in this thesis. Field oriented control algorithm is implemented for control of DFIG based variable speed wind turbine system. Fundamentals of FOC algorithm consists of clarke-park transformations, specification of the angular velocity of the rotating frame and specification of orientation type. By using these fundamentals, according to the specified angular velocity of the rotating frame by applying clarke-park transformations, mathematical model of DFIG based variable speed wind turbine system is obtained at dq rotating frame and then according to the specified orientation types performed the control of the system by applying FOC. In accordance with theoretical information provided, DFIG based variable speed wind turbine system is designed by using Matlab/Simulink programme. Control of grid connected 500kW of power the system is performed by applying classic PI controllers. Simulation results are showed and control of the system and power transmission to grid is implemented succesfully. Keywords: Wind turbine, Doubly fed induction generator, Field oriented Control.