Drive solution enables efficient wind power

Conventional wind turbines normally employ fixed-speed rotors and in high wind conditions they have to contend with large torque fluctuations that can cause power output variations, through the generator, of up to 100 percent. The new design counters this problem by employing a unique gearbox and clutch combination that allows rotor speed adjustment through variations in the pitch angle of the blades. This enables power output, through the generator, to be maintained at a constant level regardless of fluctuations in wind speed. In cases of overspeed the rotor reaches a fully feathered position and cuts out but the clutch allows the generator to continue running.

A conventional system requires extremely heavy and robust assemblies in order to contend with the large fatigue loads in high wind conditions. The new design, which incorporates a swept blade diameter of 33m, can attain speeds of 50rpm and is about 50 percent lighter than conventional wind turbines. This improves the cost to weight ratio and reduces operating costs as only three percent of the rated power is consumed by the components.