Maximising wind turbine performance: how optical fibre sensors help to provide low cost, predicable green energy

Wind Energy is now globally accepted as a key technology for helping to deliver clean and efficient renewable energy for the 21st century.  But delivering clean electricity in a cost-competitive energy market has required many technology innovations in the design and operation of the new generation of multi-megawatt Wind Turbine Generators (WTG), which require rotors in excess of 100m and that must operate, unattended, in harsh offshore environments. This talk show how Fibre Bragg Grating (FBG) based sensor systems provide a key enabling technology for real-time monitoring and control of WTG rotor loading, for optimizing the operating strategy during periods of blade icing and for adjustment of the turbine alignment to provide maximum energy capture. It begins by looking at how embedding FBG sensors into the composite laminates of WTG blades provides a fatigue resilient, lightning immune method of monitoring localized strains in the blade structure, but in doing so it also highlights some of the engineering challenges that were overcome to ensure that the sensors and interrogator hardware are suitable for 20 year operation in the harsh climatic, electrically charged, vibrating environment of the WTG rotor. It then shows how real-time blade load data is used by the WTG control system to dynamically manage the pitch settings of each blade and so respond to the constantly changing wind conditions and minimize structural overloading. Finally the talk concludes with a look at how further advanced signal processing of optical sensor blade load data provides real-time health and diagnostics.  This enables a remotely located Wind Farm Operator to detect the onset of damaging blade ice, to optimize the orientation of the turbine for maximum energy return and to schedule maintenance activities for times when their offshore turbines are most accessible.