光纤振动传感理论与实验研究

发布时间：2018-01-08 07:05

本文关键词：光纤振动传感理论与实验研究　出处：《华北电力大学(北京)》2017年博士论文　论文类型：学位论文

【摘要】：振动检测已广泛应用于电气设备、大型工程结构和基础实施等的状态监测中,可实现对被监测对象的健康状态评估、故障预警与诊断等功能,具有重要的现实意义。与传统的振动传感器相比,光纤振动传感器具有抗电磁干扰、电绝缘、耐腐蚀、易复用、易组网等特点,更适合在电力系统及其它环境恶劣的场合应用。现有光纤振动传感器存在带宽窄、结构复杂的问题,所以,探索新的不同类型、不同结构的光纤振动传感器非常必要。论文针对光纤振动传感器存在的不足,分别提出并研制了新型波长调制型和强度调制型光纤振动传感器。为了减小温度对强度调制型传感器的影响,论文设计并搭建了FBG波长解调系统,并对传感器结构进行了改进。论文首先对FBG传感特性及振动传感原理进行了分析,在此基础上,采用光波和机械波耦合的原理提出并研制了铝圆柱封装的新型FBG振动传感器,搭建了基于匹配光栅法的FBG波长解调系统,测试了传感器的性能,并通过对匹配FBG进行合理封装,减小了温度对传感器的影响;然后,论文分析了光纤中光的模式和现有强度调制型光纤振动传感器的原理,提出并研制了悬臂梁结构的强度调制型光纤振动传感器,分析并实验测试了悬臂梁的长度、宽度和厚度及光纤在悬臂梁下的位置对传感器性能的影响,实验测试了传感器的稳定性、线性特性和温度特性。论文提出的两种类型的传感器采用了新的封装结构,具有带宽大、结构简单的特点,但存在温度稳定性的问题。针对所设计的强度调制型振动传感器的温度稳定性问题,论文提出了采用FBG测量环境温度对振动进行温度补偿的方法。为了解调FBG的中心波长,论文设计并搭建了带有F-P标准具校准功能的FBG波长解调系统,F-P标准具的应用,提高了FBG波长解调的精度;论文对设计的强度调制型光纤振动传感器结构进行了改进,与FBG波长解调系统相结合,设计并搭建了强度和波长同时解调的传感系统,实现了振动和温度的同时测量及温度对振动测量的补偿。实验测试了振动和温度同时测量的相互影响、温度补偿的效果及振动测量的灵敏度。通过对传感器进行改进,使振动测量的温度稳定性和灵敏度得到了明显提高。
[Abstract]:Vibration detection has been widely used in the condition monitoring of electrical equipment, large engineering structure and foundation. It can realize the function of health state evaluation, fault warning and diagnosis of the monitored object. Compared with the traditional vibration sensors, optical fiber vibration sensors have the characteristics of anti-electromagnetic interference, electrical insulation, corrosion resistance, easy reuse, easy networking and so on. It is more suitable for applications in power systems and other harsh environment. The existing optical fiber vibration sensors have the problems of narrow width and complex structure, so we explore new types of vibration sensors. The fiber optic vibration sensor with different structure is very necessary. In order to reduce the influence of temperature on the intensity modulation sensor, the FBG wavelength demodulation system is designed and built. The structure of the sensor is improved. Firstly, the characteristics of FBG sensor and the principle of vibration sensing are analyzed. A novel FBG vibration sensor encapsulated by aluminum cylinder is proposed and developed by using the principle of optical and mechanical wave coupling. A FBG wavelength demodulation system based on matching grating method is built and the performance of the sensor is tested. The effect of temperature on the sensor is reduced by the reasonable encapsulation of matching FBG. Then, the paper analyzes the mode of light in the optical fiber and the principle of the existing intensity modulated optical fiber vibration sensor, and proposes and develops the intensity modulated optical fiber vibration sensor with cantilever structure. The effects of the length, width and thickness of the cantilever beam and the position of the optical fiber under the cantilever beam on the performance of the sensor are analyzed and experimentally tested. The stability of the sensor is tested. Linear and temperature characteristics. The two types of sensors proposed in this paper adopt a new packaging structure, which has the characteristics of large bandwidth and simple structure. However, there exists the problem of temperature stability, aiming at the temperature stability of the intensity modulated vibration sensor. In order to demodulate the central wavelength of FBG, this paper presents a method of temperature compensation by using FBG to measure ambient temperature. The paper designs and builds the FBG wavelength demodulation system with F-P standard calibration function and the application of F-P standard device, which improves the precision of FBG wavelength demodulation. In this paper, the structure of the intensity modulated fiber optic vibration sensor is improved, combined with the FBG wavelength demodulation system, and the sensing system of intensity and wavelength demodulation is designed and built. The simultaneous measurement of vibration and temperature and the compensation of temperature to vibration measurement are realized. The effect of temperature compensation and the sensitivity of vibration measurement are improved, and the temperature stability and sensitivity of vibration measurement are obviously improved by improving the sensor.
【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TP212

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