中国电机工程学报2016，Vol.36Issue(23)：6560-6569,10.DOI:10.13334/j.0258-8013.pcsee.162023
全光纤电流互感器传感机理建模分析
Mechanism Analysis and Modeling on the Sensing of Fiber-optical Current Transformers
摘要
Abstract
The measurement accuracy of all fiber current transformers is affected by a variety of internal and external factors. In this paper, an infinitesimal distributed parameter model of FOCT sensing unit was built and the mechanism of the linear birefringence in the sensing unit was revealed, that is, diagonal elements of the polarization tensor are not equal. Combined with the mathematical model of photoelectric conversion, the open loop mechanism of FOCT was obtained. And based on the theory above, two methods to improve the measurement accuracy of FOCT were putting forward. One is by using a new type of sensing materials and a new sensor head structure. The other is by using the feedback signal to construct the closed loop structure. By using COMSOL, the coupling of optical fields and magnetic fields was realized, which provided the model foundation for the coupling of complex multi-physics fields in FOCT sensor units. Besides the influence of birefringence, the measured current, the bending radius of the optical fiber and the refractive index of the fiber core on the measurement results was also analyzed. The study shows that the linear birefringence is caused by the change of the refractive index of the sensing material, and it reduces the measurement sensitivity. Under different external conditions (such as measured current), the influence of the same birefringence on the measurement results is different. The smaller the refractive index is, the larger the rotation angle will be. The linear birefringence caused by the bending radius of the sensing element is small, and the ideal Faraday rotation angle can be obtained by the segmentation compensation method. By simulation analysis the validity of the distributed parameter model was verified.关键词
全光纤电流互感器/法拉第效应/分布参数模型/双折射/开环结构/有限元法Key words
all fiber current transformers/Faraday effect/distributed parameter model/birefringence/structure of open loop/finite element analysis分类
信息技术与安全科学引用本文复制引用
李岩松,李霞,刘君..全光纤电流互感器传感机理建模分析[J].中国电机工程学报,2016,36(23):6560-6569,10.基金项目
国家自然科学基金项目(51277066)。Project Supported by National Natural Science Foundation of China (51277066) （51277066）
