Preparation And Performance Of Flexible PLLA/FeCoV Current Sensor

With the rapid development of science and technology,the demand for electrical energy is also growing,and at the same time,various electronic devices are also increasing.In this context,in order to ensure the safe operation of electronic equipment,it is necessary to accurately judge and optimize its state assessment and fault location.The current sensor can detect the power consumption state of the electronic device by acquiring the characteristic parameters of the current.Among them,non-contact current sensors are widely used due to their isolation from primary current,safety and convenient measurement.According to the different detection principles,non-contact current sensors are divided into Hall type,giant magnetoresistance type,optical type and magnetoelectric composite type.Among them,magnetoelectric composite current sensors based on magnetoelectric composites show good development potential due to their advantages of simple fabrication,miniaturization,self-powering,and high sensitivity.However,due to the limited space and high internal temperature of electronic devices,flexibility and high heat resistance are required for current sensors.In view of this,this thesis proposes a new type of magnetoelectric current sensor with flexibility and heat resistance,and studies the performance of the magnetoelectric current sensor theoretically and experimentally.The specific work content and conclusions of the thesis are as follows:1.Using COMSOL Multiphysics finite element simulation software,the magnetic flux density distribution,stress distribution,displacement distribution and electric potential distribution in the flexible magnetoelectric composite were studied.When the external magnetic field is 20 Oe,the output voltage of the flexible magnetoelectric composite reaches 0.8 m V.In addition,the output voltage of the flexible magnetoelectric composite increases linearly with the increase of the external magnetic field.2.Researches are carried out on magnetostrictive materials,piezoelectric materials(thickness and blending with VB₂)and the interface coupling between them in flexible magnetoelectric composites.The results show that the selection of magnetostrictive material Fe Co V,piezoelectric material PLLA(thickness of 20?m and blended with 15wt%VB₂)and the use of in-situ preparation methods can make flexible magnetoelectric composites obtain the best performance while considering flexibility and heat resistance.Under an applied magnetic field of 20 Oe/60 Hz,the output voltage of the flexible magnetoelectric composite is as high as 0.76 m V.3.The key parameters of the magnetoelectric current sensor are tested.Among them,the sensitivity of the magnetoelectric current sensor is as high as 0.64 m V A^-1,the linearity exceeds 0.996,the average error is 3%,and the performance remains stable in the bending state and 120°C high temperature.The output voltage of the magnetoelectric current sensor is 1.2 m V,0.6 m V,4.2 m V,and 5.7 m V when the distance from the resistance,mobile phone charger,vacuum cleaner and hair dryer is 2 mm.In addition,the magnetoelectric current sensor can charge the 4.7?F capacitor to 2.35 V in 300 s.For different states of the mobile phone,the output voltage waveform of the magnetoelectric current sensor will also be different,and finally the application of the magnetoelectric current sensor in current detection,self-energy supply and mobile phone state monitoring is realized.