Study On Fiber Optic Icing Sensors For Wind Turbine Blades

The detection of wind turbine ice is a systematic process,and high measurement accuracy and reliability are both fundamental criteria of icing detection technology.Wind turbine icing can significantly impact the regular operation of wind turbines.Many ice detection systems based on various detection principles have been developed over the past few decades thanks to the tireless work of researchers both domestically and abroad.One of these is fiber-optic icing sensors,which have quickly attracted the general public’s interest since their introduction due to their great sensitivity and broad detection range.After decades of research and development,fiber-optic icing sensors have made some progress,but they still have drawbacks such as poor detection accuracy,limited measurement range,and inability to distinguish between different forms of ice.To solve the inadequacies of the current fiber optic icing sensor,we have developed a fiber optic icing sensor based on the reflecting light intensity modulation approach and total reflection concept.The following sections comprise the work in this essay.(1)The light intensity modulation function of the fiber-optic icing sensor was built by integrating reflection and scattering concepts based on the properties of light propagation in ice.(2)The fiber-optic icing sensor was designed based on the dual fiber pair structure and total reflection principle,The fiber-optic icing sensor simulation was carried out using the ray tracing method.The received light intensity profile of the fiber-optic icing sensor with different types of icing on the probe surface and the light intensity modulation function of the fiber-optic icing sensor were studied.After that,the influence of the iceair interface roughness and the structural parameters of the fiber-optic icing sensor on the light intensity modulation curve is analyzed.(3)The fiber-optic icing sensor’s peripheral circuit was created using the weak signal detection method.It consists of an optoelectronic conversion circuit,a preamplifier circuit,an FPGA-based square waveform generator,and an FPGA-based voltmeter to detect the DC voltage signal output from the lock-in amplifier.The LED light-emitting diode’s light-emitting frequency is modulated so that it flashes at 500 Hz.(4)The fiber-optic icing sensor was validated using low-temperature icing experiments.The calibration curves of the optical intensity modulation function and ice thickness for different icing temperature ranges were established by the experiments.The experimental results show that based on the total reflection principle,the discriminant fiber can better discriminate different icing types according to the calibration curve and improve the detection accuracy of ice thickness.