悬臂型压电发电装置固有频率与能量输出特性的研究

发布时间：2019-01-04 19:38

【摘要】：悬臂型压电发电装置能够直接将机械能转换成电能,具有结构简单、加工方便、转换效率高等优势。该发电装置在谐振条件下能够产生很高的输出电压。其固有频率与材料的尺寸和力学性量切相关;合适的外加负载其能够产生较大的能量输出。所以研究此类发电装置的固有频率与能量输出对于提高发电能力具有重要意义。本文以正压电效应为基础,基于压电振子的振动模式,支撑方式等条件,建立了压电发电理论模型。将压电陶瓷PZT-5H制作成不同尺寸的压电振子。分别选择不同厚度的黄铜片、铝合金、不锈钢作为金属基片。以环氧树脂E51与胺类固化剂W93混合物作为粘合剂。对悬臂型压电发电装置进行固有频率和能量输出的测试。结合理论模型与试验分析,从压电振子尺寸、金属基片尺寸、金属基片的种类三个主要影响因素出发,分析了不同条件下固有频率的变化规律,研究发现固有频率随压电振子与金属材料长度的增加而降低,随材料厚度的增加而线性升高;当金属基片种类发生改变化时,固有频率随金属基片刚度系数的增加呈现递增的关系。该结论与理论推导的结果基本一致。验证了理论的准确性,并据此总结出固有频率随结构尺寸的变化规律。为优化悬臂型压电发电装置结构尺寸提供了依据。能量输出实验结果发现,输出电压随频率的变化呈现先升高后降低的变化趋势,通过该变化趋势可以判断固有频率的大小。针对结构尺寸进行了实验研究,总结发电装置的尺寸对发电能力的影响。将合适的负载阻抗接入测试电路,结果表明此发电装置符合电路分压特性,从功率随负载的变化关系可以明显看出,合适的负载阻抗能够使输出功率明显提高。
[Abstract]:Cantilever piezoelectric power generation device can directly convert mechanical energy into electric energy, which has the advantages of simple structure, convenient processing and high conversion efficiency. The generator can produce high output voltage under resonant condition. The natural frequency is related to the size and mechanical properties of the material, and the proper external loading can produce large energy output. Therefore, it is very important to study the natural frequency and energy output of this kind of power generation device. Based on the positive piezoelectric effect, the theoretical model of piezoelectric power generation is established based on the vibration mode and supporting mode of piezoelectric oscillator. The piezoelectric ceramic PZT-5H is fabricated into piezoelectric oscillators of different sizes. Different thickness brass sheet, aluminum alloy, stainless steel as metal substrate. The mixture of epoxy resin E51 and amine curing agent W93 was used as binder. The natural frequency and energy output of cantilever piezoelectric generator are measured. Based on the theoretical model and experimental analysis, the variation of natural frequency under different conditions is analyzed according to the three main influencing factors: the size of piezoelectric vibrator and the type of metal substrate. It is found that the natural frequency decreases with the increase of piezoelectric oscillator and metal material length, and increases linearly with the increase of material thickness. When the type of metal substrate changes, the natural frequency increases with the increase of the stiffness coefficient of metal substrate. The conclusion is basically consistent with the theoretical results. The accuracy of the theory is verified and the variation of the natural frequency with the structure size is summarized. It provides the basis for optimizing the structure size of cantilever piezoelectric power generation device. The results of energy output experiments show that the output voltage increases first and then decreases with the change of frequency, and the magnitude of natural frequency can be judged by this trend. Based on the experimental study of the structure size, the influence of the size of the generator on the power generation capacity is summarized. The appropriate load impedance is connected to the test circuit. The results show that the power generation device accords with the circuit voltage characteristics. It is obvious from the relationship between the power and the load that the output power can be improved obviously by the appropriate load impedance.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM619

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