Study On High-efficiency Magnetoelectric Heterostructure Gyrators And Energy Transfer Between Layers

Magnetoelectric(ME)gyrator is a four-wire-two-port power electronic device with passive,linear,lossless,non-reciprocal and other characteristics.It can realize the direct conversion of voltage/current and capacitance/inductance nonreciprocity.In the case of power devices,it can also realize functions such as fast impedance matching and power transmission,which has huge development potential and has been widely used in high-efficiency power electronic devices and other fields.The ME gyrator is made of ME composite material as the core component and close-wrapped copper solenoids on its periphery.Its core principle is to use the product effect of magnetostrictive effect and piezoelectric effect to achieve ME conversion.In the process of magneto-mechanical-electric energy conversion,the efficiency of magneto-mechanical conversion and mechanical-electric conversion mainly depends on the energy conversion characteristics of the material itself.The previous research on the improvement of power conversion efficiency mainly focused on this direction,but the loss mechanism in the piezomagnetic/piezoelectric material energy transfer process via interface coupling is currently not clear.So there is a lack of necessary theoretical basis and data support in the process of further improving the power conversion efficiency of the ME gyrator by reducing the loss.Aiming at this problem,a piezomagnetic/piezoelectric laminated ME gyrator is designed and manufactured in this paper,as well as its ME characteristics are measured and analyzed.After researching,Ni_0.7Zn_0.3Tb_0.02Fe_1.98O₄material has a higher dynamic piezomagnetic coefficient of 42.6ppm/Oe under the optimal bias magnetic field.The three-layer laminated structure gyrator is prepared and its ME characteristics as well as power conversion are measured.Characteristics,the ME voltage coefficient at resonance 59.01k Hz is 383V/cm Oe,and the power conversion efficiency can reach 80.3%at a bias magnetic field of 22Oe and a load of 3.5k?.At the same time,in order to further quantitatively analyze the energy transfer loss between layers in the ME laminated structure,this paper designs and builds a non-contact optical speed measurement system to measure the vibration speed of the piezomagnetic layer and the piezoelectric layer separately.The resonance frequency of each layer is same and the maximum vibration speed difference is not more than 5%,which can be regarded as a relatively static motion.Therefore,it is believed that the speed loss mainly exists in the epoxy resin layer of the laminated surface.Through the analysis of the dynamic energy integral formula,it is known that about 29%of the kinetic energy is lost in the process of energy transfer between layers.The research and exploration of the magneto-mechanical-electric dynamic energy conversion in this paper provides research ideas and technical references for further improving the power conversion efficiency of the ME gyrator.