磁致伸缩-电磁复合式宽带振动能量采集技术研究

Vibration energy harvesting technology based on magnetostrictive material has many merits, such as high energy conversion efficiency and high reliability. It attracts widespread attention in structural health monitoring and industrial automation control applications. Considering the hysteresis of magnetostrictive materials and the narrow response band of vibration energy harvester, this project proposes the magnetostrictive - electromagnetic hybrid vibration energy harvesting technology with the characteristic of the adaptive resonant frequency. The hybrid structure of magnetostriction and electromagnetic method is adopted in the vibration energy harvester. The mechanical-magnetic-electric coupling model of magnetostrictive materials and the electromechanical coupling dynamic model of hybrid vibration energy harvester are established. The loss mechanism and energy conversion law of the magnetostrictive materials is researched considering the dynamic hysteresis effect. In order to improve the energy harvesting efficiency, the structure parameters of the hybrid vibration energy harvester are optimized using the finite element analysis method. The key technologies with wide response frequency for the optimized design method of hybrid vibration energy harvester are concluded. The research results can provide a theoretical basis for vibration energy harvesting system based on functional materials. And the vibration energy harvesting system has important scientific significance and application prospects in the field of self-powered wireless sensor networks and system network.

基于磁致伸缩材料的振动能量采集技术以其能量转换效率高、可靠性高的特点，在环境结构健康监测和工业自动化控制等领域受到广泛关注。本课题针对磁致伸缩材料存在磁滞效应和振动能量采集器的工作频带较窄等问题，提出一种具有谐振频率自适应特性的磁致伸缩-电磁复合式振动能量采集技术研究。采用磁致伸缩式与电磁式复合的振动能量采集结构，建立磁致伸缩材料机-磁-电耦合模型和复合式振动能采集器的机电耦合动力学模型，掌握动态磁滞效应条件下磁致伸缩材料的损耗机理与能量转换规律。利用有限元分析方法对振动能量采集器的结构参数进行优化设计，提高系统的能量收集效率，突破振动能量采集器宽工作频率设计的关键技术，总结磁致伸缩-电磁复合式宽带振动能量采集器的优化设计方法与构型特性理论。本课题的研究成果可以为基于功能材料的振动能量采集系统的设计提供理论基础，具有重要的科学研究意义，在无线传感器网络、物联网等领域应用广泛。

本项目基于磁畴偏转理论，分析了应力作用下逆磁致伸缩效应原理，对超磁致伸缩材料的物理属性进行了试验测试与分析。结合超磁致伸缩材料的材料特性定性分析了影响输出电压的因素，为结构设计提供理论依据，提出了磁致伸缩-电磁复合式振动能量采集器的结构。对逆磁致伸缩能量采集部分建立线性数学模型，推导了空载及负载两种情况下输出电压的表达式，对电压波形进行仿真分析；对电磁能量采集部分应用“弹簧-质量块-阻尼”模型推导输出电压、输出功率的表达式，采用Ansoft Maxwell有限元方法对模型进行静磁场和瞬态磁场仿真，得到线圈输出电压的图像并分析仿真结果。总结磁致伸缩-电磁复合式宽带振动能量采集器的优化设计方法，对影响电压输出特性的因素进行分析，包括磁致伸缩材料的尺寸、永磁体尺寸、输入机械振动的压力和频率等。研究设计了磁致伸缩-电磁复合式振动能量采集器实验室原理样机，搭建了试验平台，并对冲击负载下的振动能量采集效果进行了测试与分析。试验结果表明所研制的振动能量采集器具有高于传统振动能量采集器的能量采集效果，验证了理论分析与设计方法的正确性。本项目的研究为基于功能材料的振动能量采集系统的设计提供理论基础，可以进一步拓展在自供能无线传感器网络等领域应用。