转子运动条件下光纤光栅的扫描光谱特性及测温误差研究  

Fiber Bragg grating scanning spectral characteristics and temperature measurement error under rotor whirling conditions

作　　者：陈思彤 黄俊斌[1] 刘文 李哲宇 顾宏灿[1] 姚高飞 CHEN Sitong;HUANG Junbin;LIU Wen;LI Zheyu;GU Hongcan;YAO Gaofei(College of Weaponry Engineering,Naval University of Engineering,Wuhan 430033,China;National Key Laboratory of Electromagnetic Energy,Naval University of Engineering,Wuhan 430033,China)

机构地区：[1]海军工程大学兵器工程学院,武汉430033 [2]海军工程大学电磁能技术全国重点实验室,武汉430033

出　　处：《振动与冲击》2024年第12期17-29,共13页Journal of Vibration and Shock

基　　金：国家自然科学基金(11774432)。

摘　　要：针对基于空间耦合传输方法的电机转子温度监测系统,采用光纤光栅的传输矩阵理论和自聚集透镜的耦合传输理论,建立了转子运动条件下光纤光栅(fiber Bragg grating,FBG)的扫描光谱模型,首先研究了扫描光谱的畸变规律及各算法的寻峰效果,结果表明:转子的涡动导致FBG扫描光谱的反射峰发生偏移,3 dB带宽减小,随着耦合损耗与原始反射峰之间的相位差发生变化,中心波长的最大扫描误差以类似正弦函数的规律发生变化,新反射峰位置由耦合损耗变化速率、FBG原始反射率及其变化速率之间的限定关系决定。协调解调仪扫描速率与转子涡动频率之间的数值关系是减轻光谱畸变的主要方法;此外,相比于半峰法和多种拟合型算法,质心法通过提取畸变光谱的重心也明显地减小了中心波长的扫描误差。然后,通过理论和试验研究了转子涡动频率与解调仪扫描频率对系统测温误差产生的影响,结果表明:随着耦合损耗周期与光谱扫描时间之比(q值)的增加,系统的最大测温误差先剧烈地减小、然后缓慢减小至稳定,令q>10是确保系统的测温误差及其波动较小的最低条件;对于转速小于200 000 r/min的转子(涡动频率小于1 667 Hz),当转子径向振动的幅值小于200μm、轴心轨迹的轴比小于3、轴心线偏转的角度小于0.1°时,采用扫描频率大于760 Hz的解调仪和质心寻峰法可以保证涡动引起的测温误差小于0.3℃,为转子测温系统的实际应用及测温误差的预估提供了依据。For the motor rotor temperature monitoring system based on the spatial coupled transmission method,the scanning spectral model of fiber Bragg grating(FBG) on the whirling rotor was established.The distortion law of the scanning spectra and the peak-finding results of each algorithm were firstly investigated.The results show that the whirling rotor leads to the shift of the reflection peaks and the reduction of the 3 dB bandwidth in the scanning spectra of the FBG.The maximum scanning error of the center wavelength changes with a sinusoidal function as the phase difference between the coupling loss and the original reflection peaks change.The position of the new reflectance peak is determined by the limiting relationship between the rate of change of the coupling loss,the original FBG reflectance and change rate between them.Coordinating the numerical relationship between the scanning rate of the demodulator and the frequency of the rotor,whirl is the main method to mitigate spectral aberration.In addition,compared with the half-peak method and various fitting-type algorithms,the centroid method also significantly reduces the scanning error at the center wavelength.Then,the effects of the rotor whirl frequency and the demodulator scanning frequency on the system temperature measurement error were investigated by theory and experiment.The results show that the maximal temperature measurement error firstly decreases drastically,and then decreases slowly,and finally stays stable,with the increase of the ratio of the coupling loss period to the spectral scanning time(q-value).q>10 is the minimum condition to ensure that the system's temperature measurement error and its fluctuation are small.For rotor speed less than 200 000 r/min(Whirl frequency less than 1 667 Hz),when the amplitude of the rotor radial vibration is less than 200 μm,the axial ratio of the axial trajectory is less than 3,and the angle of axial line deflection is less than 0.1°,the use of a scanning frequency greater than 760 Hz demodulator and the c

关 键 词：光纤光栅(FBG)传感器 转子温度监测系统 转子运动 畸变光谱 寻峰误差 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]