Load Alleviation on Wind Turbines using Camber Morphing Blade Tip

This paper investigates the load alleviation capability of a camber morphing blade tip on multi megawatt scale HAWTs. A span-wise variation of camber at the outer blade region is proposed that blends seamlessly to the non-morphing part of the rotor blade. The NREL 5MW reference turbine is used as baseline design, where the outer 30% of the blade is linearly cambered with the maximum camber realized at the blade tip. The results obtained during simulations, following the IEC standard, indicate that the camber morphing blade tip is able to mitigate vibrational loads, such that reduction in fatigue loads range between 8%-37% for most wind turbine components. Furthermore, the controller is also capable of reducing ultimate loads due to extreme turbulence in the order of 30%-60%. Finally, a large reduction in peak-to-peak response, in the order of 43%-90%, is achieved for several turbine components under wind gust or extreme direction change.