一种新结构的全光纤电流传感器

A optical fiber current sensor with new sensing configuration

光纤的固有双折射是影响全光纤电流传感器精度的主要原因，它除了与光纤本身有关外，还与工作的环境温度、振动等有关，如何消除双折射是光纤电流传感器研究的关键问题。提出了一种双光源双输出的全光纤电流传感器新结构，它不需要两路参数严格对称，同时减小了振动和温度变化引起的双折射的影响。实验表明，该结构的传感器在20g的振动强度下，测量结果的线性度在±0．5％以内；同时，在电流为50A，温度从-20℃～50℃变化时，其输出信号的线性度在±2％以内。

The intrinsic birefringence of the sensing fiber is main cause which affects the measuring precision of optical fiber current sensor. It is not only affected by the features of fiber itself but also is under the influence of environmental factors such as temperature and vibration, and how to eliminate it is the key research topic, A new sensor configuration with double light channels and photodiodes is presented. The double channels parameters of sensor need not symmetrical seriously. The influences of birefringence by temperature variation and vibration are restrained. Experimental results show that the signal linearity is achieved under ±0.3% with the sensor head exposed to a vibration level of acceleration 10 g, and the signal linearity is achieved under ±20% with the current through the conductor is 50 A and the environmental temperature from -20℃ to 50℃.