温度自适应FBG-GMM电流传感器

发布时间：2018-08-25 17:30

【摘要】：为了保障智能电网安全稳定运行,避免灾难事故产生,研究高安全性、高稳定性、高灵敏度、大量程、长寿命、结构简单、体积小、成本低的磁场检测技术显得尤为迫切,探索新的科学途径实现电流检测已成为传感技术工作者研究的新热点,特别是光纤电流传感技术是热点中的热点。将超磁致伸缩材料(超磁致伸缩材料(Giant Magnetostrictive Material,简称GMM)与光纤光栅(Fiber Bragg Grating,简称FBG)相结合的FBG-GMM电流传感器,由于其具有结构简单、灵敏度高的优点备受关注。但是,该电流传感器需要克服温度交叉敏感的问题。为了解决此问题,本文将FBG-GMM与磁路系统相结合,提出了基于磁路系统的FBG-GMM电流传感器,利用双FBG对磁场的不同响应来消除温度对电流测量的影响。此外,利用磁路系统的聚磁特性,可进一步提高电流的测量灵敏度。基于单聚磁回路系统和“十字”型传感头的FBG-GMM电流传感器研究。设计了“十字型”FBG-GMM传感头,将其放入C型聚磁回路的开口处,使传感光栅的径向与磁场方向相同,参考光栅的径向与磁场方向垂直,因此传感光栅和参考光栅具有不同的磁场响应。考虑到传感光栅和参考光栅具有相同的温度响应,采用双光栅匹配解调的方式实现了电流解调及温度补偿。利用ANSYS Maxwell软件分析了GMM棒长度、截面积以及狭缝宽度对导磁回路聚磁能力的影响,结果表明当间隙越小、GMM横截面越小、GMM长度越短时,磁路的导磁能力越强。实验结果表明:传感FBG和参考FBG具有相同的温度响应;交流安匝电流在1.0~138.2 A的变化范围内,该传感器呈线性变化,测量精度为16.0 m V/A。在线性变化范围内,交流电流的峰值失真误差小于2.2%。基于双聚磁回路系统的FBG-GMM电流传感器研究。设计了并列的C型双磁路系统,每个磁路系统内放置一个FBG-GMM传感头,两磁路加载相反的偏置磁场,当被测磁场同时加载到双磁路上时,其中一个磁路内的GMM棒伸长而另一个磁路内的GMM棒收缩,导致一个FBG的波长向长波方向漂移,而另一个FBG的波长向短波方向漂移。考虑到两FBG具有相同的温度响应,采用双FBG匹配解调的方式实现了电流解调及温度补偿。为了增大匹配解调的线性范围及灵敏度,本部分选用的FBG均为平顶FBG。利用ANSYA Maxwell仿真分析两磁路间距对双磁路系统聚磁能力的影响,仿真结果表明磁路间距越小,两磁路的相互干扰越大;但当磁路间距大于20 mm时,两磁路间的干扰可忽略不计。实验结果表明:交流安匝电流在0.6~159.8 A的范围内变化时,该传感器呈线性变化,测量精度为30 m V/A;该电流传感器在20~80℃范围内可实现温度自动补偿。在线性变化范围内,交流电流的峰值失真误差小于1.8%。
[Abstract]:In order to ensure the safe and stable operation of smart grid and avoid disaster accidents, it is urgent to study magnetic field detection technology with high security, high stability, high sensitivity, large range, long life, simple structure, small size and low cost. Exploring new scientific approaches to realize current detection has become a new research hotspot of sensor technology, especially optical fiber current sensing technology. The FBG-GMM current sensor which combines the giant magnetostrictive material (GMM) and the fiber Bragg grating (FBG) has attracted much attention because of its simple structure and high sensitivity. However, the current sensor needs to overcome the problem of temperature cross-sensitivity. In order to solve this problem, a FBG-GMM current sensor based on magnetic circuit system is proposed by combining FBG-GMM with magnetic circuit system. The effect of temperature on current measurement is eliminated by using the different response of double FBG to magnetic field. In addition, the measurement sensitivity of the current can be further improved by using the magnetic accumulation characteristics of the magnetic circuit system. Research on FBG-GMM current sensor based on monomagnetic loop system and cross sensor head. The "cross" FBG-GMM sensor head is designed and put into the opening of the C-type magnetic gathering loop. The radial direction of the sensing grating is the same as the magnetic field direction, and the reference grating is perpendicular to the radial and magnetic field direction. Therefore, the sensing grating and the reference grating have different magnetic field responses. Considering that the sensing grating and the reference grating have the same temperature response, the current demodulation and temperature compensation are realized by double grating matching demodulation. The influence of length, cross section and slit width of GMM rod on the magnetic accumulation ability of magnetic conduction circuit is analyzed by using ANSYS Maxwell software. The results show that the magnetic conductivity of magnetic circuit is stronger when the gap is smaller and the cross section of GMM is shorter. The experimental results show that the sensor FBG has the same temperature response as the reference FBG, and the AC ampere-turn current varies linearly in the range of 1.0V / 138.2A, and the measurement accuracy is 16.0 MV / A. In the linear range, the peak distortion error of AC current is less than 2.2. Research on FBG-GMM current Sensor based on Duplex Magnetic Loop system. A parallel C-type double magnetic circuit system is designed, in which a FBG-GMM sensor head is placed in each magnetic circuit system, and the opposite bias magnetic field is loaded by the two magnetic circuits. When the measured magnetic field is loaded on the double magnetic circuit at the same time, The extension of GMM rod in one magnetic circuit and the contraction of GMM rod in the other lead to the drift of the wavelength of one FBG in the direction of long wave and the wavelength of the other FBG in the direction of short wave. Considering that the two FBG have the same temperature response, the current demodulation and temperature compensation are realized by double FBG matching demodulation. In order to increase the linear range and sensitivity of matching demodulation, all the FBG selected in this part are flat-top FBG.. The influence of the two magnetic circuit spacing on the magnetic accumulation ability of the dual magnetic circuit system is analyzed by ANSYA Maxwell simulation. The simulation results show that the smaller the magnetic circuit spacing, the greater the mutual interference between the two magnetic circuits, but when the magnetic circuit spacing is more than 20 mm, the interference between the two magnetic circuits is negligible. The experimental results show that the AC ampere-turn current varies linearly with a measuring accuracy of 30 MV / A when the AC ampere-turn current varies in the range of 0.6159.8 A. the current sensor can automatically compensate the temperature in the range of 2080 鈩，

本文编号：2203597