非线性磁电换能器模型的谐振磁电效应分析及其输出功率优化

Resonance magnetoelectric effect analysis and output power optimization of nonlinear magnetoelectric transducer model

基于非线性磁致伸缩材料的本构方程,建立了一种“磁-力-电”多场耦合的层合磁电换能器的有限元模型,研究了不同偏置磁场下的谐振磁电效应.基于等效电路模型和二端口网络理论,实现了对谐振状态下磁电系数和等效源阻抗的完整求解.在磁电换能器与负载电阻之间引入优化的L节匹配网络,在提升负载功率的同时拓展了工作带宽.仿真结果与相关文献数据吻合,证实了该模型的准确性和有效性.仿真结果表明,所研究的层合磁电换能器,其磁电系数在450 Oe的偏置磁场下达到51.79 V/(cm·Oe)@51.4 kHz,在350 Oe的偏置磁场下达到极限输出功率–3.01 dBm@50.4 kHz.以保证负载功率为前提,通过优化匹配网络,可实现2.30 dB的功率提升和2.27倍的带宽拓展.本文所建立的非线性有限元模型充分考虑了偏置磁场对谐振磁电效应的影响,该研究结果对小型化磁耦合无线功率传输系统的设计和性能提升具有重要的指导意义.

Magnetoelectric composites comprised of piezoelectric and magnetostrictive materials,are widely used in magnetic field sensing,energy harvesting,and transducers.This work establishes a finite element model of a laminated magnetoelectric transducer coupled with magneto-elastic-electric fields based on the constitutive equation of the nonlinear magnetostrictive material.Then,the resonant magnetoelectric effect under different biased magnetic fields is studied.Based on the equivalent circuit model and the two-port network theory,the magnetoelectric coefficient and the equivalent source impedance under the resonant state are completely solved for the first time.Introducing optimized L-section matching networks between the magnetoelectric transducer and the load resistor can increase the load power and expand the operating bandwidth.The simulation results are consistent with the data in the literature,thus confirming the accuracy and effectiveness of the model.The simulation results demonstrate that the magnetoelectric coefficient reaches 51.79 V/(cm·Oe)at 51.4 kHz and 450 Oe bias magnetic field,and the ultimate output power of–3.01 dBm at 50.4 kHz and 350 Oe bias magnetic field.To ensure the load power,the power increase of 2.30 dB and the bandwidth expansion of 2.27 times are achieved by optimizing the matching network.The nonlinear finite element model in this work takes into account of the magnetoelectric effect under the acoustic resonance state and quantifies the ultimate output power.The magnetoelectric transducer model can obtain high magnetoelectric coefficient,load power,and power density in a small volume,providing a significant advantage in terms of equilibrium.The research results are of great importance in guiding the design and performance improvement of miniaturized magnetically coupled wireless power transfer systems.