【作者】 袁江波；

【导师】 陈维山； 谢涛；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2011， 博士

【摘要】 近年来,随着微机电系统和无线网络技术的不断发展,便携式微电子产品无论是在军事领域还是在民用工业领域都得到了广泛的应用,但以化学电池为微电子、无线网络和MEMS等低耗能器件的供能方式存在质量大、体积大(不利于电子产品微型化)、寿命有限、需定期更换以及由此产生的环境污染等诸多问题。因此,如何向微电子产品无线供能已经成为当前迫切需要解决的问题。基于压电能量转换的压电发电装置是解决此问题的一个行之有效的方法,通过压电发电装置俘获微电子器件工作环境中的振动能并将其转化为电能,从而实现为微电子器件无线供能。由于悬臂梁压电振子直接承载能力小,不能直接应用于高载环境中。针对此问题,本文将以承载能力大且不需任何附加装置就可直接应用于高载环境中的圆盘式压电发电装置为研究对象,针对几种典型的圆盘式压电发电装置的理论计算模型、结构分析和输出性能进行全面的研究。钹型压电振子是一种典型的圆盘式压电换能器,本文首先以钹型压电发电装置为研究对象,根据碟簧理论和压电理论,建立了钹型压电发电装置的理论发电模型并进行了数值模拟分析。利用有限元手段分析了其主要结构参数对压电振子输出电压和谐振频率的影响关系,针对钹型压电振子存在环向应力集中而导致其力电转化效率降低的问题,提出了几种对钹型压电振子进行开槽结构的优化方式,分析了槽结构参数对其输出性能的影响关系并确定了其中发电性能最佳的开槽形式。在此基础上,为了研究压电振子结构与能量存储电路间的相互机电耦合作用,建立了钹型压电振子—能量存储电路多物理场机电耦合作用分析模型,并分析了振动频率和负载对压电发电装置输出性能的影响关系,为钹型压电发电装置的结构设计和优化提供理论依据。接着以力电转化效率更高的鼓型压电发电装置为研究对象。利用薄板振动理论和压电理论,建立了鼓型压电换能器的谐振频率计算模型。将鼓型换能器作为压电振子进行压电发电性能研究,建立了鼓型压电发电装置发电性能的数学模型并进行数值模拟分析。对鼓型压电振子进行有限元仿真分析,获得了其关键结构参数对鼓型压电振子谐振频率和发电特性的影响规律,并在此基础上,对鼓型压电振子—能量存储电路进行了多物理场机电耦合作用仿真分析,为鼓型压电发电装置的实际应用提供了理论依据。在综合考虑了这两种压电换能器的优点后,提出了一种钹鼓复合型压电换能器,它既具有钹型换能器高的承载能力还具有鼓型换能器高的机电能量转化效率。首先分析了钹鼓复合型换能器主要结构参数对其发电、变形性能和谐振频率的影响关系,以此确定换能器合理的结构尺寸参数;然后建立复合型压电振子—能量存储电路的机电耦合作用分析模型,针对负载和振动频率对压电发电装置输出性能的影响关系进行了研究。综合前述章节的研究内容,根据压电振子的发电特点和实际需要,选择并设计了合理的能量存储电路;采用合理工艺制造了压电振子实验样机,最大程度地减小工艺环节的误差对压电振子各项性能指标的影响;最后分别对本文所研究的几种压电发电装置的发电性能进行实验测试。研究结果表明,压电发电装置输出功率随振动频率增加而增加;随负载的增大先增大后减小,存在一个最佳的匹配负载使输出功率达到最大,实验验证了理论分析的正确性。鼓型压电发电装置的能量密度最高,最大达到了980 W/m3,但相对钹型压电发电装置其承载能力小,不能直接工作于高载环境中,而钹鼓复合型压电发电装置既具有高的能量密度且具有高的承载能力,相比较来说是其中综合性能最优异的压电发电装置。更多还原

【Abstract】 With the recent advances in microelectro-mechanical systems and wireless technology, the demand for portable electronics is growing rapidly in martial filed and civil industries. However, a traditional electrochemical battery can no longer meet the needs of advanced sensing technology due to its limited large volume, large weight, service life, difficulty in replacement and environmental pollution. Thus, the power of micro-electronics products is need to imminently consider. Much attention has been paid to scavenging energy from the ambient environment in recent years because it can supply the power micro-electronics products. The piezoelectric cantilever energy harvester has difficulties to work directly without some fractures in the high stress condition due to its less ability of the mechanical stability. It has been found that the circular metal-ceramic transducers have the capability to withhold dynamic high stresses. The calculated modal, structural analysis and output power of the typical metal-ceramic energy harvesters were investigated in detail.Cymbal harvester is a typical metal-ceramic transducer which is studied for scavenging vibration energy. Based on the force analysis and piezoelectric theory, a mathematical modal of the cymbal transducer was presented to calculate the output power of the energy harvester. The effects of structural parameters on the output voltage and resonant frequency of the cymbal transducer were analyzed by ANSYS. Some optimal methods which could increase the conversion efficiency were presented to decrease the circular stress of the cymbal transducer. The effects of the structural parameters of slots on the output voltage were also analyzed and an optimal method was confirmed. In order to study the coupling action between piezoelectric and electric circuit sides, a model of the piezoelectric structure and electric circuit was developed, and the effects of the vibrated frequency and resistive load on the output power were presented which can be useful to design the cymbal energy harvester.The drum energy harvester was studied due to the high effective piezoelectric charge coefficient. Based on the vibrated theory of the thin plate and piezoelectric theory, a modal was developed to calculate the resonant frequency. Power generation from the drum transducer was modeled by using the piezoelectric theory. The relationship between the structural parameters, output voltage and resonant frequency of the drum transducer were analyzed by ANSYS. The coupling action between piezoelectric and electric circuit sides of the drum energy harvester which can be useful for application was studied.A novel transducer which should withhold cyclic high stresses and have high effective piezoelectric charge coefficient was design due to the advantages of the cymbal and drum transducer. The effects of the structural parameters on the output voltage, displacement and resonant frequency were analyzed to confirm the reasonable structural parameters. A model of the piezoelectric structure and electric circuit of the cymbal-drum transducer was developed to analyze the effects of the vibrated frequency and resistive load on the output power.Integration of the previous studies, energy storage circuits were designed. And a reasonable technics which can decrease the errors among the transducers was selected to fabricate the transducer. The output power of the energy harvesters were measured by the experimental methods. The results show that the output power initially increases with the resistive load, whereas it will decrease when the resistive load is further increased. At each of these frequencies, it has an optimal load corresponding to the maximum output power density. It can be found that the results obtained from the theoretical modal are in very good agreement with those from experimental results. The results also show that the drum energy harvester has the highest power density which can reach 980 W/m3, however the drum transducer can’t used directly in the high stresses condition. The cymbal-drum transducer has the high effective piezoelectric charge coefficient and can work directly in the high stresses condition. Compared with the cymbal and drum energy harvester, the cymbal-drum energy harvester is optimal.更多还原