【作者】 姚国珍；

【导师】 李永倩；

【作者基本信息】 华北电力大学(北京) ， 电工理论与新技术， 2017， 博士

【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。更多还原

【Abstract】 Vibration detection has been widely used in condition monitoring of electrical equipment,large engineering structure,infrastructure and etc,which can realize health condition assessment,fault warning and diagnosis.Therefore it has important practical significance.Compared with conventional sensors,optical fiber vibration sensor offers important advantages such as EMI immunity,electrical insulation,corrosion resistance,multiplexing capabilities,easy networking and etc.It is more suitable for application in power system and many other harsh environments.The existing fiber optical vibration sensor has the problems of narrow bandwidth and complex structure,so it is necessary to study new optical fiber vibration with different types and structures.Aimed at the shortcomings of optical fiber vibration sensor,the thesis proposes and develops new wavelength modulation and intensity modulation optical fiber vibration sensors respectively.To reduce the influence of temperature on the intensity modulation sensor,the thesis designs FBG wavelength demodulation system and improves the structure of the sensor.Based on the analysis of sensing characteristic and vibration sensing principle of FBG,the thesis proposes and develops a new type FBG vibration sensor packaged by aluminum cylinder.The principle the sensor adopts is the coupling of optical wave and mechanical wave.To demodulate the FBG wavelength,a matched FBG sensing demodulation system is set up,under which the sensor characteristics are tested.By means of packaging the matched FBG appropriately,the effects of temperature on vibration sensing are reduced.The thesis analyzes the modes in fiber and the principles of existing intensity modulation optical fiber vibration sensor,and then proposes and develops a new type vibration sensor based on cantilever structure.It also studies the influences of the fiber location and the dimension parameters of the cantilever on the frequency response.In addition,the stability,linear and temperature characteristics are tested.The two types of sensors mentioned above adopt new package structure,and have the characteristics of large bandwidth and simple structure.But the performance of the sensors can be influenced by temperature.Aimed at the temperature stability of the intensity modulation sensor,the thesis proposes a method of temperature compensation by FBG.To obtain the wavelength of FBG,the thesis designs and develops FBG wavelength demodulation system.By using F-P etalon the wavelength demodulation accuracy is improved.Furthermore,the thesis improves the structure of the intensity modulation sensor.Combined with the FBG demodulation system,the thesis designs and develops sensing system which can measure vibration and temperature simultaneously.The mutual influences of vibration and temperature measurement,the results of temperature compensation and the sensitivity of vibration measurement are tested.The temperature stability and sensitivity of vibration measurement are enhanced obviously after improvement of the sensor.更多还原