Consider the following wind turbine with a constant speed generator, connected to the rotor via a conventional gearbox:
Blade radius, R = 60 m
Design tip speed ratio lambda_D = 7
CP, max at lambda = lambda_D, = 0.45
CP = (3CP, max/ lambda_D^2) lambda^2 - (2CP, max/ lambda_D^3) lambda^3
Mechanical efficiency = 0.9
Generator rotational speed = 1800 rpm
Gear ratio = 180:1
Rated wind speed = 12 m/s
Cut-out wind speed = 22 m/s
Air density = 1.23 kg/m3
i) Find the power curve for the turbine
ii) Illustrate the power curve together with one for which Cp always equals Cp,max (until reaching rated wind speed)