Fibre Optic Blade Monitoring (FOBM)

For measuring mechanical loads in rotor blades, towers, and other structural parts, strain gauges are the state-of-the-art solution. Optical fibres are expected perform better for this purpose if it comes to drift, stability, and lifetime. Since 2001, ECN is experimenting with optical fibres to assess the added value for the wind turbines. Three areas for improvement were identified:

• the quick and easy application of sensors in the field;
• the reliability, accuracy, and performance of the interrogators; and
• the acquisition and analyses of the measured data to provide information relevant for O&M purposes.

Since 2005 ECN is working on all three areas in collaboration with suppliers of fibre optic measurement systems. Field experiences are being carried out at the N80 turbines at the EWTW.