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The Cantilever-Sensor is a new product in the Bachmann portfolio, designed for the continuous recording of structural loads on the rotor blades of wind turbines. 

Cantilever sensors measure strain, producing a value comparable to the output from electrical strain gauges or fibre-optic strain sensors. However, by using an inductive displacement measurement the CLS itself is not subject to mechanical deformation. 

Compared to conventional sensor technologies, the robust design of the CLS offers the following advantages: 

  • The measurement principle guarantees the longterm stability of the sensor.
  • The longer reference distance minimizes the influence of local inhomogeneities, typical of composite materials used for blade construction.
  • The installation is simple and reproducible.

The CLS has a wide range of applications:

  • The signal provides real time blade loading information suitable for individual pitch control.
  • Continuous recording of the signal allows a facilityspecific estimation of the remaining service life.
  • Comparison between the different blade loadings on a single wind turbine can identify problems such as pitch errors or individual blade damage.
  • The response time and sensitivity enable sampling rates sufficient to capture structural oscillations of the blade, for ice detection, and structural integrity studies.

The monitoring of critical blade loads was the main focus for developing the CLS. The use of CLS signals for individual pitch control allows coordination between turbine design and operational strategy in a load-optimized way in order to considerably reduce the levelized cost of energy of modern turbines. 

It also enables further specific adjustment of the pitch control strategies, either to maximise output or to extend life, providing further significant savings.

System overview