A Revolutionary Concept Featuring a Ring-Shaped Generator
Members of the MegaWindForce (MWF) team developed a highly efficient variable transmission system back in 2012. While researching whether this invention would contribute to the efficiency of wind turbines they became aware of the catch 22 situation of the wind industry: rotors need to be bigger to harvest more energy, resulting in lower numbers of revolutions, which makes the design of generators more complex and relatively more expensive. A new concept was developed, where the main shaft was replaced by a ring. This revolutionary concept resulted in several patents.
By Ton Bos, co-founder and shareholder of MegaWindForce, The Netherlands
Concept
One of the most severe challenges in designing a traditional horizontal axis wind turbine is optimising the blade joints to the rotor hub. With the growth of the size of turbine rotors, the driving torque at the blade root section increases more than linearly with the length of the blade (with the rotor radius cubed). When the same materials are used, the weight increases cubically with size, demanding heavier constructions to withstand forces. The low number of revolutions made it necessary for the nacelle to grow for the direct drive generators or introduced heavy gearboxes. By replacing the main shaft by a ring-shaped generator-support combination the disadvantages of classical upscaling are eliminated.
