基于光纤光栅的风机桨叶监测系统设计

Design of Monitoring System for Wind Turbine Blade Based on Fiber Bragg Grating

风力发电机桨叶作为捕获风能的重要部件,其运行的安全性与稳定性将直接影响风电机组的效率与安全,因此亟需采取一种准确、有效的方法对风机桨叶的应变进行监测。论文采用布拉格光栅传感器(fiber Bragg grating, FBG)与解调设备对桨叶应变信号进行实时监测。首先使用高速模拟数字转换器(analog to digital converter, ADC)对FBG传感器的信号进行采集,通过现场可编程逻辑门阵列(field programmable gate array, FPGA)将数据解调,再利用串行外围设备接口(serial peripheral interface, SPI)与微控制器芯片建立通信,通过远距离无线电(long range radio, LoRa)配合第4代移动通信技术(fourth generation communications technology, 4G)将信号传递至上位机。其次采用小波变换对噪声进行滤波,设置阈值去除异常波形,提高了寻峰精度。最后对布拉格光栅中心波长进行分析,验证了波长漂移量与应力呈正相关。结果表明:此系统能够实现对风力发电机桨叶应力变化的监测。

Wind turbine blades are an important component for capturing wind energy,and the safety and stability of their operation will directly affect the efficiency and safety of wind turbines.Therefore,it is essential to adopt an accurate and effective method to monitor the stress of wind turbine blades.In this paper,the fiber Bragg grating sensor(FBG)and demodulation equipment are used to monitor the blade stress signal in real time.Firstly,a high-speed analog to digital converter(ADC)is used to collect the signal of the FBG sensor.After demodulating the data,the field programmable gate array(FPGA)uses the serial peripheral interface(SPI)bus to establish communication with the microcontroller chip,and transmits the signal to the host computer through the long range radio(LoRa)and the fourth generation communications technology(4G)module.Secondly,the wavelet transform is used to filter the noise,and the threshold is set to remove abnormal waveform,which improves the peak-finding accuracy.Finally,the center wavelength of the fiber Bragg grating is analyzed,and it is verified that the wavelength shift is positively related to the stress.The results show that the system can monitor the stress change of wind turbine blades.