摘要
为改善光纤电流互感器的性能,设计了一种再入式光纤电流互感器.基于光干涉、相干信号检测和耦合模理论,研究了再入式光纤电流互感器的光源选择、核心器件参数确定及信号的调制与解调方式.理论研究结果表明,宽带光源是再入信号检测的重要前提;通过选择适当的调制信号占空比来控制采样时间点,是实现再入信号检测的必要保证;传感光纤环中耦合器的耦合比的最佳值由信号再入次数决定.基于对第5次再入信号的有效检测,当环境温度在-10~60℃范围内变化时,实现了对10~60A范围内电流的测量.实验结果表明,系统标度因子的线性度良好.用信号再入代替多匝传感光纤,可有效抑制绕制过程引入的应力双折射对系统标度因子线性度的影响;结合结构参数优化,还能有效克服单匝传感光纤情形下材料低维德尔系数导致的测量灵敏度较低的问题.
To improve the performance of fiber-optic current transformers,a re-entrant fiber-optic current transformer is designed.Based on theories of two-beam interference,signal detection and mode coupling,the selection of the light source,the determination of its optimal coupling coefficient of the sensing ring,and the modulation and demodulation for re-entrant signals are studied.The theoretical research results show that the usage of a wide line-width light source and the control of sampling time points by suitable duty cycles of modulation signals are essential to the detection of the related re-entrant signals.And the optimal coupling coefficient can be determined by the signal re-entrant times.Furthermore,based on the effective detection of the fifth re-entrant signal,the currents varying from 10 to 60 A are measured under the condition that the environmental temperature varies from-10 to 60℃.The experimental results show that the linearity of the scale factor of this system is good.Replacing the multi-circle sensing ring by re-entrant signals can effectively eliminate the effect of the strain-induced birefringence on the linearity of the scale factor.By structural optimization,the low sensitivity caused by the Widdel coefficient when single-circle sensing rings are used can also be improved.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2009年第S2期37-41,共5页
Journal of Southeast University：Natural Science Edition
基金
教育部新世纪优秀人才支持计划资助项目(NCET-05-0465)
关键词
光纤电流互感器
干涉仪
再入
调制
fiber-optic current transformer
interferometer
re-entrant
modulation
