Encoders are a forgotten component in wind turbines—at least until they fail. Wind turbines are a challenging application for encoders, something many OEMs and end-users discover just after installation. The constant vibration and thrust is tough on tiny encoder bearings (and for absolute encoders it’s tough on internal gearboxes). Another problem is temperature cycling combined…

  Encoders are used in several locations in a wind turbine but the three key applications are blade pitch, slip rings, and generator control. Each has special challenges but all must tolerate environmental extremes common to a nacelle, such as heat over 100°F. The high temperatures expand what is initially clean lab air and forces…