| 摘要 |
A wind turbine has at least one turbine blade 2 mounted to a rotor and provided with at least a first strain sensor 4 for measuring mechanical strain of the turbine blade. Detecting formation of ice on the wind turbine blade comprises detecting changes in an output signal of the strain sensor 4 due to changes in the mass of the turbine blade 2 caused by the formation of ice on the turbine blade. Methods of using the strain sensor(s) to determine speed of rotation, angle of inclination, pitch, torque, power, bending moments, blade fatigue and wear, drive train degradation are also described. Methods of calibrating an optical fibre strain sensor in a wind turbine by rotating the wind turbine and processing the output of the strain sensor to identify a periodic component of the output signal indicative of mechanical strain due to the effect of gravity on the turbine blade are also claimed. The methods of calibration may include determining the unstrained strain sensor output by reference to the midpoint of the peak to peak amplitude of the periodic component of the output signal; or determining a relationship between the output value of the first strain sensor and the bending moment due to the mass of the turbine blade by reference to the peak to peak amplitude of the periodic component of the output signal. |
