A GMM-FBG Current Sensor With Enhanced Sensitivity Based on a Double-Ring Lever

With the wide applications of giant magnetostrictive material fiber Bragg grating (GMM-FBG) current sensor in the field of power, the improvement of sensitivity and temperature stability has become more and more important. A new GMM-FBG current sensor with enhanced sensitivity and better temperature stability based on a double-ring lever has been designed, fabricated, and experimentally demonstrated. The sensitivity of the sensor has been enhanced based on the lever amplifying mechanism, while the temperature influence can be eliminated by using the differential processing. The 3-D model of the sensor is established and the parameters have been optimized. Experimental results show that the sensitivity of the sensor is 10.223 pm/A and the temperature compensation error is about 0.1 pm/°C.