During the past years, wind turbine technology has improved and the demand for new installations is increasing. The transmission system operators have looked into different technologies.
Three technologies are discussed in this Masters thesis. The first is the simple induction generator, which is one of the oldest technologies, but is becoming installed less because of increasing requirements of grid codes in Europe. Doubly fed induction generator (DFIG) technology is also examined, and the impact of two features, the crowbar and the chopper. Lastly direct drive synchronous generator (DDSG) technology is discussed.
The disconnection of wind farms due to fault in the western part of France is examined. The volume of shed wind power is highly dependent on the voltage level at which the fault occurs. The higher the voltage, the more wind farms are shed. The topology of the grid is also an important factor with regard to wind power shedding.
A study has been performed on the fault behaviour of a large DFIG wind farm installed near some nuclear power plants. If the fault occurs near these generating units, the wind farms will affect the stability of the power system, and the critical clearing time will decrease. The installation of active power regulation in the wind farms can reduce this effect.