Draw-wire sensors used for wind turbine rotor blade testing

Draw-wire displacement sensors from Micro-Epsilon are playing a vital role in the testing of the latest generation of wind turbine blades at the Fraunhofer Institute in Bremerhaven, Germany.

The test rig at the Fraunhofer Institute simulates the distortion of rotor blades due to the effects of wind forces. The tip of the rotor blade can be distorted by up to 10m due to mechanical loads. The rig is designed to measure rotor blades up to a length of 70m.

During tests, the rotor blade itself is mounted horizontally in the test rig. Steel cables are attached to the rotor using guide pulleys and fixed to the rotor blade at various positions along its length, either directly or via mechanical clamps. Twelve draw-wire sensors from Micro-Epsilon are used to measure the distortion.

Two draw-wire sensors for each cable are mounted to the rails on the floor. These sensors measure the movement and the distortion of the rotor blade. The P115 sensors are from Micro-Epsilon’s wireSENSOR range and have measuring ranges of between 3m and 10m. The sensors operate with a digital output signal and are particularly robust due to their aluminium housing.