基于多场耦合轴向激励的旋转式压电发电机研究

A rotating piezoelectric generator excited axially by multifield-coupled action is presented, and the forming theory and method of the capability for a rotating piezoelctric elemet to vibrate axially and generate electric energy will be investigated theoretically and experimentally. For the advantages such as, high reliability, wide frequency band, fitting to high-speed/even-speed rotation and so on, the generator is suitable for the self-powered sensor monitoring system of rotating structures in the fields of the aviation/spaceflight and vehicles, or to harvest fluid energy. At first, the dynamics/kinematics models of the rotating piezoelectric generator will be established according to the coupling relationship among the machanical and electrical systems. On this basis, computer simulation will be utilized to obtain the coupling performance of the multi-fields, the influence regularity of multifield-coupled action on the performance of the axial excitation force and the relative-motion relationship of the mechanical components, and the optimal matching relationship of the system elements. Secondly, the axial vibration shape and the energy-generation perfaomance of the rotating piezoelectric element will be studied. The influence of the structures/parameters of mechanical unit and electrocircuit-types/element-parameters of electrical control unit on the energy conversion capability as well as energy conversion efficiency of the piezoelectric generator will be analyzed. Based on this, the key factors restricting responding speed and orderly axial-reciprocating vibration of the peizoelectric element will be picked out. At the same time, the essential principle for the generator to produce enenctric energy at high speed and wide bandwidth will be found out. According to the above research results, several kinds of axis-type and wheel-type rotating generators excited by three excitation methods will be fabricated using different sorts of piezodiscs/piezocantilevers and energy conversion methods. A series of experiments on the test prototypes will be carried out so as to obtain the optimal excitation schemes, mechanical structures,and energy harvesting methods. Finally,10 rotating piezleelectric generators as well as the key parameters/technology for their design/fabrication will be completed and provided.

提出利用多物理场的耦合作用使旋转的压电振子产生轴向振动并发电，研究这种轴向激励及发电能力的形成理论与方法，进而构造宽频带、高可靠性、且适于匀/高速的微小型旋转式压电发电机，用于航空航天/行走机械等非结构环境中旋转体的自供电传感监测或流能发电。主要内容：统筹考虑发电机系统要素间的耦合关系，建立系统动力学/运动学模型，通过模拟仿真获得多场间的耦合特性及其对激振力和部件相对运动关系的影响规律、以及合理的系统参数匹配关系；研究压电振子的轴向振动形态及其能量转换特性，分析机械单元结构/激励方式、电控单元电路形式/器件参数等对发电能力/效率的影响规律，提取制约高速旋转压电振子动态响应速度及有序轴向往复振动的关键要素，揭示多场耦合轴向激励形成宽频带发电能力的本质机理；进行3种激励方式的轴/轮式样机制作与试验，获得最优激励方案、机械结构及能量回收方案；试制样机至少10台，提供设计方法及关键制造技术参数。

提出通过多场耦合作用使压电振子产生轴向往复振动发电，用于旋转体自供电监测或流能回收。主要内容：①进行了压电振子理论建模仿真及有限元分析，研究了不同边界条件下矩形/圆形压电振子结构及材料参数对其发电能力的影响规律，获得了恒力/位移激励时单/双晶的矩形/圆形压电振子厚度比、材料弹性模量比及圆形压电振子半径比等对其变形量及发电性能的影响规律；提出了曲面限位及预弯型等应力发电装置，并进行了模拟仿真与试验测试，证明限位/预弯方法可使应力分布均匀，提高发电能力及可靠性；②通过Comsol建模仿真和试验测试研究了不同磁铁配置方式（受激磁铁与激励磁铁均相吸/相斥、吸-排间隔）时的定角比（相邻两激励磁铁间夹角与激励磁铁对应的角度之比）、转角比（受激磁铁转角与激励磁铁对应角之比）对轴/切向的耦合特性、幅值、方向及偏置特性等的影响规律；③利用傅里叶级数展开法及叠加原理建立了一般周期激励下压电振子的响应模型并进行了仿真，获得了稳态的时域/频率特性与压电振子类型（阻尼系数及刚度）及附加质量/受激磁铁尺度、激励磁铁尺度/数量/磁极配置方式（吸/排/吸排间隔）/回转半径等参数的关系；④以圆形/悬臂梁压电振子为换能器，进行了轴式（有固定支撑）旋转发电机（振子转动）和旋磁激励（振子固定）发电设计制作与试验，获得了激励磁铁数量、压电振子类型/刚度、附加质量、磁铁尺度及激励距离等对发电性能（时域波形和幅频特性）的影响规律；⑤以圆形为换能器，进行了轮式（无固定支撑）旋转发电机（振子转动、激励磁铁浮动及滚动）与旋磁激励发电（激励磁铁转、振子浮动）制作与试验，证明利用惯性力与旋转体形成相对运动构造轮式发电机的可行性；⑥进行了刚性/磁力限位压电梁旋磁激励发电机制作与试验，研究了不同限位方式（单/双侧、刚/弹性）及激励磁铁数量时的电压-转速特性，证明该方法可实现振子刚度及最佳转速的调整，有效降低输出电压波动（变形量均衡、可靠性高）、提高有效带宽；⑦制作了多振子旋磁激励发电机，研究了不同电路连接方式（振子直激串/并联、经整流串/并联）时的幅频/带宽特性；增加了涡轮式压电流体发电机以及流体耦合式压电发电机的相关研究。结合研究计划及拓展工作，培养了硕士研究生8人，尚有2名硕士从事相关工作；公开发表学术论文23篇（5篇SCI/EI双检、14篇EI检索），获得授权发明专利15项、尚有11项发明专利处于实质审查中。