The Model Research And Experimental Analysis On GMM-FBG AC Current Sensing System

Nowadays, facing to the contradiction among economic development, electric powerconstruction and environmental degradation, the smart grid will be the trend of the powergrid development in the future, The modern power grid with larger capacity, highervoltage and more digital will puts forward higher requirements on the current sensor.Recently with the rapid development of optical fiber sensing, optical current sensor withanti-electromagnetic interference, high insulation resistance and wide range of dynamicresponse has become a hotspot. The current sensor based on Giant MagnetostrictiveMaterial (GMM) and Fiber Bragg Grating (FBG) is analyzed in theory and experiment.The main research work includes:On the basis of in-depth analysis on GMM and FBG sensing principles, the FiberBragg Grating sensing models are established including strain, temperature and their crosscoupling. In consideration of the influence of GMM hysteresis nonlinear on sensingproperties, GMM hysteresis nonlinear sensing model is researched which is based on thesecondary domain model. And on this basis, GMM-FBG ac current sensor’s sensingmodel considering the hysteresis is established.To establish a nonlinear hysteresis model for GMM-FBG current sensor, an improvedPreisach hysteresis model is put forward.This model has improves the weight function andthe saturated output of the model. The particle swarm optimization algorithm is used toidentify the parameters for the improved Preisach model.Through comparing the resultbetween identification and experiment, it is verified that the improved hysteresis modelhas excellent prediction ability.GMM-FBG ac current sensor’s electromagnetic properties is analyzed through thefinite element analysis software ANSYS. The effects of the sensor’s internal magneticfield gived by different magnetic circuit is compared.The structure optimization of thetransducer is completed through data analysis.Through constructing the experimentplatform, the experiment research on the performance of GMM-FBG ac current sensor iscarried on.