Research On Magnetoelectric Effect And Current Sensor Of Laminated Composite Materials

Magnetoelectric composite materials have the characteristics of fast magnetoelectric response,high sensitivity,and simple preparation at room temperature.Devices that use magnetoelectric composite materials as sensitive components have the characteristics of no need of additional power supply for their power supply and no need to access the main circuit,and they are passive devices.Compared with giant magnetostrictive materials,FeSiB amorphous alloy materials,which are the constituent phases of magnetoelectric composite materials,require a smaller bias magnetic field and have higher magnetostrictive sensitivity.Based on the theoretical model of laminated composite materials,the equivalent circuit method and the direct derivation based on the constitutive equation are used to study the magnetoelectric voltage coefficient,and the influence of the limited input impedance of the cable and the display instrument on the magnetoelectric voltage is taken into consideration.The magnetoelectric response characteristics of materials at low frequency and resonance frequency are studied,and the main factors affecting the magnetoelectric coefficient are analyzed.Two groups of amorphous alloy/PZT laminated magnetoelectric composite materials were prepared by bonding,where each group of materials corresponds to a different aspect ratio and thickness ratio in order to study the size optimization of the composite material.Aiming at the shortcomings of sensor sensitivity reduction caused by the use of sampling resistors in the magnetoelectric coefficient test device in the past,an integrated Hall sensor was selected to measure the alternating magnetic field..TL431 reference power supply circuit and differential subtraction circuit are used to offset the zero output of the Hall sensor and amplify the output signal.A calibration device for the Hall sensor was built,and the Hall sensor was calibrated.The frequency response characteristics of composite materials with different aspect ratios and thickness ratios under low frequency and resonance conditions are studied by the experiment.The results show that the material exhibits better frequency response characteristics in the low frequency region.As the aspect ratio increases,the magnetoelectric voltage coefficient of the material gradually increases,and the resonance frequency gradually decreases;there is an optimal thickness ratio to maximize the magnetoelectric coefficient.As the thickness ratio increases,their resonance frequency gradually increases.Using amorphous alloy/PZT,NdFeB and a magnetic ring with an air gap to design and prepare a ring current sensor based on the magnetoelectric effect,it can perform non-contact measurement of large currents in the range of 0-100 A.A large current generating device was built to study the sensitivity and nonlinear error of the toroidal magnetoelectric current sensor.The measured sensitivity of the current sensor is 7.6m V/A,and the relative error of the current measurement result is less than 1.83%.