摘要
光纤EFPI超声传感器是基于Fabry-Pérot光学干涉原理来检测局放超声信号,具有灵敏度高、抗电磁干扰等优点,广泛应用于电气设备局部放电的检测。应用压强平衡光纤EFPI超声传感器在变压器内部测局部放电时,相对于在空气中测量,存在信号的幅值有较大衰减、传感器的灵敏度会降低的情况。本文研究了检测变压器中局放超声信号的内置式光纤EFPI超声传感器的信号衰减情况,并基于有限元法对光信号在F-P腔体的传播特性进行了仿真。通过仿真和实验确认了内置式传感器光纤端面的光反射率,论证了光在F-P腔的损耗。
The optical fiber EFPI ultrasonic sensor is based on the Fabry-Pérot optical interference principle to detect partial discharge ultrasonic signals. It has the advantages of high sensitivity and resistance to electromagnetic interference. It is widely used in the detection of partial discharge in electrical equipment. When using the pressure-balanced optical fiber EFPI ultrasonic sensor to measure partial discharge inside the transformer, the signal amplitude will be attenuated, and the sensitivity of the sensor will be reduced compared to the measurement in the air. This paper studies the signal attenuation of the built-in optical fiber EFPI ultrasonic sensor that detects the partial discharge ultrasonic signal in the transformer. And based on the finite element method, the propagation characteristics of the optical signal in the F-P cavity are simulated. The light reflectivity of the fiber end face of the built-in sensor is confirmed through simulation and experiment, and the light loss in the F-P cavity is demonstrated.
