A horizontal-axis two-blade wind turbine feeds power to the grid through a doubly-fed induction generator (DFIG) operating with slip power control. The grid frequency is 50 Hz and the generator has 6 poles. The diameter of the wind turbine is 50 m and the maximum blade efficiency is 48% at tip speed ratio (TSR) of 5.5. The gearbox has a speed ratio of 45 and efficiency of 90%. The air density at the hub height is 1.22 kg/m. If the wind turbine is operating at maximum efficiency and the wind speed at the hub. height is 12 m/s, (a) Determine the power of the wind and the mechanical power in kW at the rotor of the induction generator (high-speed shaft). (5 Marks) Calculate the slip of the induction generator and the slip power (Ps). Under this operation mode, are the power converters processing electric power from the rotor to the grid or vice versa? Justify your answer. (8 Marks) (b) (c) The hub height of this wind turbine is 80 m and the air temperature is 4C. Determine the altitude of the terrain with respect to the mean sea level. Consider the following expression: pression TANIMA -00341 212 353 T MOTEPT300M - HEA e HTTW 21/T2Y? (4 Marks) (d) Comment on two advantages and two drawbacks of two-blade wind turbines with word respect to three-blade wind turbines when used for electricity generation. MlingA (4 Marks) (e) In the context of horizontal-axis wind turbines, sketch an upwind configuration and a downwind configuration. Comment on the main advantage and the main disadvantage of downwind turbines with respect to upwind turbines. q aid (4 Marks) VEMA