对称螺旋嵌套型全光纤小电流传感器的直流特性

DC Characteristics of the Symmetric Spiral Nested Full Optical Fiber Low Current Sensor

全光纤电流传感器提供了一种先进的非接触电流测量技术,由其良好的抗干扰性能等优点引起了广泛关注。然而,基于法拉第磁光效应的全光纤电流传感技术在绝缘诊断等领域的应用受到了很大的限制,主要原因是这种传感器技术在测量小电流信号时缺乏稳定性和可靠性。针对此问题,首先设计并建立了对称螺旋嵌套型全光纤小电流传感器实验系统,基于此实验系统对30 m A^6 A的直流电流进行测试,在此基础上研究法拉第磁光偏转角随测试电流的变化规律。然后应用COMSOL多模场耦合仿真软件对所设计的光纤传感系统的传输场进行模拟仿真,得到对称螺旋嵌套型全光纤电流传感器对法拉第磁光效应的响应度,发现这种结构与传统全光纤结构相比可提高灵敏度600倍左右。最后将实验结果与仿真结果进行对比分析,并研究了对称螺旋嵌套型结构的特性。结果表明,对称螺旋嵌套型全光纤小电流传感器可准确测量30 m A以上的小电流,解决了全光纤电流传感器无法准确测量10 A以下小电流的技术难题。未来将基于所建立的实验系统对传感器的潜在应用进行进一步的探索。

Optical fiber current sensors provide an advanced non-contact approach to measure elec tric currents, which receive great attention by its good performance on anti-interference. However, the full optical fiber current sensing technology based on the Faraday rotation effect has limitations in insulation diagnosis etc., which is attributed to the lack of stability and reliability in low current measurement. Firstly, a new structure of symmetric spiral nested full-optical low current sensor and the corresponding experiment system are set up in the laboratory to measure 30 mA-6 A DC current. Based on the current sensor, the relationship between the Faraday rotation angle and the test current is studied. Secondly, The COMSOL software is used to simulate the transmission field of the optical fiber sensing system. The simulation results show the responsivity about the Faraday effect of the symmetric spiral nested full optical fiber low current sensor. It can be found that the sensitivity of the new structure is 600 times higher than that of the traditional structure. Finally, the experimental results are compared with the simulation results. Then the characteristics of the symmetric spiral nested structure are analyzed. It can be seen that the symmetric spiral nested full optical fiber low current sensor can accurately measure low current above 30 mA, which solves the technical problem of low current accurate measurement under 10A. The result obtained from the present work is useful for further research on the optical fiber current sensor.