Fibre Bragg grating sensor system monitors operational load in a wind turbine rotor blade

Abstract

A fibre Bragg grating sensor system has been installed in a horizontal axis wind turbine and was successfully tested for already more than one year. We report the requirements, system design and realisation of the sensor system for continuous on-line load monitoring of the rotor blades, and provide examples of strain measurement results.

A survey of health monitoring systems for wind turbines

“…Due to cost and technical difficulty compared to laboratory settings, few field tests have been performed for SHM of blades. In one example, Schroeder et al [122] documented the use of a fiber optic system in a blade over the course of two years. The system includes one temperature and six strain sensors.…”

Feasibility study on a strain based deflection monitoring system for wind turbine blades

“…Applying the boundary condition, the solution become Eq. (12). In order to express the structural differences between the beam and the blade, we propose a modified form.…”

“…As we mentioned in Section 2, interpolation function, Eqs. (12) and (13), are evaluated. The modal testing results are interpolated by Eqs.…”

“…The aims of measurement by FBG sensor are, for instance, to detect damage [10] or monitor structural responses such as bending loads [11][12][13].…”

Influence of lamination process on optical fiber sensors embedded in composite material

“…A typical FBG has a sinusoidal refractive index variation over a defined length [11,12]. The reflected wavelength (k B ), called the Bragg wavelength, is defined by the relationship:…”