Two prototype prototype wind turbines are scheduled to be installed over the next two years demonstrating what is said to be the largest direct-drive permanent magnet wind turbine drive yet devised. The generators, developed by Converteam in Europe, are going into wind turbines from Alstom that also feature the world’s longest turbine blades and 6 MW power output.
The turbines employ special structural technology which diverts unwanted stresses from the wind safely to the turbine’s tower. Only turning force, or torque, is transmitted to the generator, which ensures sufficient air gap is maintained between the generator rotor and stator, thereby promoting reliability. This is important because the direct drive systems have no mechanical gearbox between the rotor and the generator.