基于LabView的光纤电流互感器一体化测试系统设计

光纤电流互感器日益成为电力系统中最重要的设备,在实用化研究中,光纤电流互感器的检测精度是重要的指标之一,而被测电流的谐波和光纤电流互感器内部的噪声往往影响其测量的准确性。因此对光纤电流互感器谐波的检测以及对其解调算法实用性的验证非常重要。为进一步的谐波治理提供依据及验证解调算法能否有效运用问题,在详细分析现有的谐波检测理论和两种解调算法原理的基础上,设计了一种基于虚拟仪器LabView的光纤电流互感器谐波检测及解调算法测试一体化系统,在快速检测电流各次谐波电平的同时解调出被测电流的信息并对比验证两种解调算法的可行性与优越性,验证结果表明第二种解调算法的精度明显优越于第一种解调算法,更能适用于光纤电流互感器的信号解调。     

全光纤电子电流互感器技术探讨

随着输电电压升高到超高压、特高压,传统的基于电磁感应机理的电流互感器技术已暴露出越来越多的内在的、难以克服的缺点。因此,用电子电流互感器取代传统的电流互感器已是大势所趋。特别是目前在电力系统大力推进智能电网技术的形势下,电力系统对全光纤电子电流互感器技术的需求日趋增长。此外,在高频电流及微弱电流测量方面全光纤电流传感技术也有重要应用。在简要介绍全光纤电流传感技术的概念、基本分类之后,阐述了目前全光纤电流互感器技术实用化过程中遇到的主要技术障碍,探讨了可能的解决办法,介绍了光纤Bragg光栅、量子点掺杂光纤及光纤纳米线/微米线等新兴技术在光纤电流传感器中的应用。     

光纤偏振态自动补偿的光纤电流互感器

提出了一种对状结构光纤电流互感器中的输入光纤偏振态进行自动补偿的新结构,并给出了理论分析和实验结果。这种结构使光纤电流互感器的稳定性和检测精度有显著提高。     

全光纤电流互感器的偏振误差研究

借助琼斯矩阵对全光纤电流互感器的偏振误差进行了研究.通过建立光纤电流互感器各主要光学器件的琼斯矩阵表达式,推出了反射式光纤电流互感器的干涉表达式,并分析了各光学器件主要参量对其测量准确度的影响.     

便携式光纤电流互感器传感头设计

针对电解铝工业中大电流测量现场环境复杂的难题,在传统光纤电流互感器的基础上提出一种便携式光纤电流互感器.对设计安装过程中由于柔性传感头光路不闭合和导体偏心引起的法拉第相移误差进行分析和有限元仿真计算,结果表明:法拉第相移相对误差随传感头不闭合度角度线性增加,随导体到非闭合点的距离增大而减小,且增加传感头匝数能减小法拉第相移误差.由于便携式光纤电流互感器准确度随导体到非闭合点的距离增大而提高,设计了一种使传感头非闭合点向一端延伸且易拆装的结构,实验测试得到该便携式光纤电流互感器的全温准确度为0.86%,满足电解铝厂准确度1%的使用要求.     

光纤法布里-珀罗传感器光纤端面反射率优化

讨论了反射光纤端面反射率对（F-P）传感器输出信号质量的影响,指出反射光纤端面反射率的提高可以克服光在F-P腔内损耗的影响,且对应传感器腔长有和其匹配的最优反射率.为了使传感器在其工作腔长范围内的输出信号整体上具有尽可能好的信号质量,采用最小均方误差法确定了反射光纤端面的最优反射率.仿真证明了采用最优反射率时的信号质量优于采用非最优反射率时的信号质量.     

光纤环保温腔体设计及其性能分析

为了改善光纤电流互感器温度性能,设计了引入保温腔体的光纤环传感头结构.在光纤环受温度扰动引起的热致相位差基础上,推导并建立了光纤电流互感器系统输出误差离散化数学模型,利用有限元分析软件分别建立了光纤环自身和光纤环配合保温腔体的有限元模型,仿真分析了在不同温度载荷下,保温腔体的热性能和采用设计的传感头光纤电流互感器的温度性能.仿真实验结果表明:所设计的保温腔体能有效控制光纤环中各匝光纤的温度变化范围,减缓光纤的温变速率,均化光纤环温度场;采用设计的传感头的光纤电流互感器系统输出误差范围明显减小,有效提高了系统测量精度.这对高精度的光纤电流互感器的制作和应用具有重要意义.     

基于光纤光栅的光学电流互感器研究

将超磁致伸缩材料(GMM)棒粘贴光纤布拉格光栅(FBG)的体系置于电流感应磁场中,构成光学电流互感器,用导磁材料构建磁路系统以约束并引导磁力线进入GMM。用永磁体材料建立偏置磁场以确定系统静态工作点,应用有限元分析磁路的磁场分布并设计了磁路的结构尺寸。利用粗波分复用器(CWDM)线性边带对光纤光栅交变应变解调,实现对交流电流信号的检测。实验测得偏置磁场为30 kA/m时,该系统在线性区最大可测电流为186 A,可获得4,3%的满量程精度。利用快速傅里叶变换(FFT),分析工频电流互感器不同输出信号的谐波分量,对输出信号进行质量评价。表明在线性区,互感器的输出信号基本不受GMM回滞特性和非线性特性的影响。     

可补偿偏置漂移的扭转光纤电流传感器

针对扭转光纤电流传感器由于环境因素（如温度,压力,振动）变化使光纤中传输光偏振态改变,从而导致传感器输出与漂移问题,提出了一种新的信号处理方法进行克服,这一方法适用于交变电流的检测,实验中通过旋转输入线偏振光偏振方向的方法检验了所提垢有效性,证明这种补偿方法对传感器置相位的任意偏移均适用。     

光纤声传感器的实验研究

采用Y型光纤传感探头结构设计了反射式光纤声传感器.该传感器利用反射式强度调制方式实现声音对光的外调制,在完成声光转换的同时可对音频信号进行滤波处理.根据薄膜振动理论分析了弹性膜片的固有频率和基频.对光纤声传感器系统的测试结果表明,输入电流超过40 mA后,发光管的发光功率与输入电流呈良好的线性关系.     

Sapphire-fiber-based white-light interferometric sensor for high-temperature measurements

We present a fiber-optic temperature sensor with a single-crystal sapphire fiber as the light guide and a sapphire wafer as the sensing element. Temperature is determined by measurement of the thermal dependence of the wafer's optical thickness by use of white-light interferometry. We applied digital signal processing techniques to analyze the sensor's spectrum. A prototype sensor was tested to 1600 degrees C and demonstrated excellent reproducibility. An accuracy of +/- 0.2% full scale was obtained. The sensor is simple, small, and flexible, with potential advantages of batch fabrication and easy calibration.     

Fabrication and comparison of thermochromic material-based fiber-optic sensors for monitoring the temperature of water

In this study, we explored the feasibility of developing two types of fiber-optic temperature sensors that can measure the temperature of water. One uses a thermochromic material such as Lophine, whose optical absorbance changes according to the thermal variation. The other uses a thermochromic pigment that gradually loses its own color through heat absorption. We measured the change in the intensity of the reflected light, which was due to the variation of the optical property of Lophine and pigments, with thermal variation. The relationship between the temperature of water and the output signal of the fiber-optic sensors was also determined. The fiber-optic temperature sensor using Lophine provided a relatively broad range of temperature measurement with low sensitivity, whereas the fiber-optic temperature sensor using a thermochromic pigment offered a high sensitivity in a narrow range of temperature measurement.     

Investigation of dual-channel fiber-optic surface plasmon resonance sensing for biological applications

A dual-channel fiber-optic sensor based on surface plasmon resonance (SPR) for self-referencing refractive-index measurements has been proposed. Most applications of fiber-optic SPR sensors are designed to measure the refractive index of a liquid or gas sample by measuring the signal from a single surface, the sensitivity and stability of which is easily affected by the fluctuation of external environmental conditions. We have designed a dual-channel fiber-optic surface sensor with two independent SPR signals from two areas of the same probe. A prototype sensor was fabricated and characterized. The preliminary experimental results demonstrate the characteristic responses of both SPR signals from two channels that independently correspond to the refractive index changes in the liquid samples with which they are in contact. The design could be extended to a multichannel sensor with further developments. The experimental results confirmed that one channel can be used as a reference sensor that could compensate for unexpected changes in bulk refraction or temperature and develop this sensor as a practicable high-sensitivity biosensing device.     

干涉型光纤传感器信号检测技术的研究

光纤传感器是一种高灵敏度传感器，而信号检测技术是它的关键技术之一。介绍了干涉型光纤传感器的信号检测方法。首先简单分析了干涉型光纤传感器相位衰落现象产生的物理机制，然后分别介绍了各种抗相位衰落信号检测方法的基本工作原理和特点，着重讨论了其中几种主要的方法，详细分析了它们的优缺点、应用场合以及技术难点。最后对各种检测方法的主要性能进行了比较，并对它们的发展前景做了展望。     

Noise performance of multiplexed fiber-optic sensor systems with optical amplifiers

The signal to noise ratio (SNR) of a multiplexed fiber-optic sensor network can be improved by inserting fiber-optic amplifiers. Several configurations of amplifiers in the sensor network are analyzed. A single fiber-optic amplifier used as a preamplifier is a good solution with high SNR. However, by distributing amplifiers in the network even higher SNR can be obtained, and identical couplers can be used throughout the network.     

Pre-filtering Effect in an Iterative Deconvolution Method and Its Application to Signal Recovery in Fiber-Optic Distributed Temperature Sensors

The signal quality of a fiber-optic distributed temperature sensor based on optical time domain reflectometry (OTDR) is improved using a pre-filtering technique in the iterative deconvolution method. Investigation of the performance is proposed using iteration conditions in which recovery rate of the signal-component is equal to that of the unfiltering technique. The recovered signal in the pre-filtering technique gives a good signal-to-noise ratio (SNR), 3 times of the unfiltered signal. Consequently, improvements in the OTDR signal with SNR of from 10 to 100 are obtained under the iterations for both distance and temperature resolutions.     

分布式光纤温度传感技术在隧道监测中的应用

介绍了分布式光纤温度传感检测原理及采用拉曼散射型分布式光纤温度传感器并将其与高速采集处理电路集成的检测方式。分析了分布式光纤温度传感技术应用于隧道火情监控的优越性。结合计算机及现场Modbus网络构建了隧道监测网络，同时还介绍了开发隧道监测网络的软硬件设计过程。现场实验表明，分布式光纤温度传感技术具有良好的应用前景和较高的推广价值。     

谱带吸收式光纤温度传感器

本文提出了一种新颖的半导体谱带吸收式光纤温度传感器系统结构.分析了半导体谱带吸收式光纤温度传感器的原理,推导了其数学模型.该传感器用反射式传感结构,以砷化镓半导体材料作为温度敏感元件,并利用除法器消除了传感器光源的波动及光纤的连接损耗,使传感器具有结构简单、抗环境干扰、高可靠性特点.文中对传感器的整个系统进行了设计和分析,并进行了实验测试,实验结果显示:该传感器在－20～110℃的温度范围内有1℃的测量精确度,并且温度从110℃降到15℃时的时间响应为25s.     

Fiber-optic acoustic sensor for nondestructive evaluation

An experimental study was conducted to investigate the applicability of fiber-optic acoustic sensors to detect internal flaws in polymeric materials. A polarimetric fiber-optic sensor embedded in a plexiglass model received the acoustic signals generated by an ultrasonic transducer. It is shown that proper control of the polarization and phase of the optical beam is required to obtain meaningful results from the amplitude of the fiber-optic sensor signal. The sensor has shown promising results in determining acoustical properties of plexiglass and locating internal defects. The attractive feature of this sensing scheme is that the optical fibers are not modified prior to embedding. Therefore, they preserve their mechanical properties which makes the embedding process much easier.     

光纤电压传感器温度特性的研究

以半波电压较高的石英晶体为敏感材料,分析了光纤电压传感器全量程的温度特性,发现其与传感器所测电压值要关;随着待测电压的从小往大增加,其输出温度变化的灵敏度逐渐由小变大。为了实现电压传感器全量程的温度补偿,必须获取两个关键的参数：一为电压传感器在无外加电压作用下的温度输出响应参数;二是敏感材料在电压作用下的温度应参数。