Real-Time Monitoring of Composite Wind Turbine Blades Using Fiber Bragg Grating Sensors

The prototype of a 2 MW wind turbine (type U88) has been tested at Taebaek, South Korea since January 2009. A real-time monitoring system with fiber Bragg grating (FBG) sensors was designed and applied to monitor wind turbine blades in operation. Differences according to the operating conditions (yawing, pitching and start-up/normal operation) were monitored accurately in real time with sensors. Additionally, using commercial FEM codes, a GFRP-based composite rotor blade was modeled, and then natural frequencies obtained from the FE modal analysis were compared with the FFT results of measured strain data. Finally, this paper provides an overview of the real-time monitoring system setups and some current test results including modal characteristics.