The Research Of Three-dimensional Magnetic Field Measurement Technique Based On Gmm-fbg Sensor

With the acceleration of China’s UHV grid construction process,the transmission line fault diagnosis technology has put forward higher requirements. Using space magnetic field measurement method locat the fault of power transmission line more and more popular. While traditional measuring instruments are difficult to meet the requirements of spatial dynamics of the magnetic field. With fiber Bragg grating(FBG) based on giant magnetostrictive material(GMM) sensor as the representative of an optical sensor system has become a hotspot in electric current and magnetic field research,on the basis of previous theory, propose a three-dimensional magnetic field measurement technique based on GMM-FBG sensor.The main research work includes:Comprehensive analysis sensing features of the FBG and GMM, discusses the FBG sensing model; analysis factors affecting the performance of the GMM, primarily hysteresis characteristics, discusses the GMM hysteresis nonlinear model based on Jiles-Atherton transformation model, and consider the establishment of a magnetic hysteresis of GMM-FBG sensor sensing models.A three-dimensional sensor-based GMM-FBG and structural parameter of the sensor are designed. Apply finite element analysis software COMSOL Multiphysics to simulate electromagnetic, structural force field of uniaxial sensors, the effects of the sensor structure, material properties and prestress of giant magnetostrictive rods inside the sensor are discussed, through data analysis to optimize corresponding parameters.Study the three-dimensional sensor error factors, establish a three-dimensional error correction model, analysis impact of the bias, scale factor and non-orthogonal on Steering deviation. A improved genetic algorithm is proposed to estimate model parameters,and analysis of the two algorithms correction effect, improved genetic algorithm proving correct errors in the three-dimensional magnetic field sensor with good results. The experimental system is set up, study of the performance of GMM-FBG sensor, the center wavelength calibration and error correction analysis of the three-dimensional sensor are conducted.