【作者】 刘智；

【导师】 谢涛；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2009， 硕士

【摘要】 随着无线传感器和便携式电子设备的应用日益广泛,以化学电池为主的供能方式存在许多明显的弊端,如体积大、供能寿命有限、需要定期更换等。为延长电池寿命、减少电子设备体积,人们开始致力于研究从环境中吸取能量并转化为电能的方法。压电发电因为具有成本低、装置简单、嵌入性好等优点,成为研究的热点之一。钹型俘能器是近年压电发电研究的一个重要方向。目前对槽钹型俘能器的研究大都是参数仿真分析,缺乏理论的指导和分析,具有一定的盲目性。本文根据力学和压电理论,在合理假设的基础上建立了钹型俘能器发电的数学模型,得出钹型俘能器发电性能随各参数的变化规律。为提高钹型俘能器的发电能力,又进一步研究和优化了开槽结构。在静力分析的基础上仿真分析了动态激振时开槽结构的性能。随后,分析了粘结层的应力,研究了改善粘结层应力的措施并仿真验证。在结构分析之后,本文研制了基于555方波控制和Buck-Boost型直流变换的压电储能电路,并进行理论分析,推导了输出功率模型以及优化了开关控制信号的参数,然后进行电路硬件设计和仿真分析,验证电路的可行性。在理论分析和电路分析的基础上,本文进一步展开了槽钹型俘能器储能实验。实验研究了输出功率随负载、激振频率的变化情况;锥面槽和环形槽结构对发电性能的提高;实验电路储能的可行性和优化性。通过实验可知,输出功率随频率增加而增加,对不同激振频率存在匹配负载使输出功率达到最高,实验曲线与理论曲线基本吻合;锥面槽和环形槽结构都能极大提高输出功率;Buck-Boost型压电储能电路输出功率与激振频率、电感、匹配负载、开关占空比、开关频率有关;Buck-Boost型压电储能电路能够降低匹配负载,在较宽的负载范围内能够获得较大的输出功率。最后,为获得更大的输出功率,提出了复合型槽钹俘能器的思想,并研究分析了三种复合型槽钹俘能器。通过理论分析和有限元仿真验证了复合型槽钹俘能器能提高输出功率,降低匹配负载。分析表明在三种复合型槽钹俘能器中多层cymbal型俘能器俘能效果最佳。更多还原

【Abstract】 With the wide use of wireless sensors and portable electronic equipments, many drawbacks of the chemical battery which can not be ignored occur, such as big size, large quality, limited battery life, periodic replacement, material waste, environmental pollution, etc. To extend battery life and reduce the volume of electronic equipment, people begin to study the method that can harvest energy from environment and convert to electricity. Piezoelectric energy harvesting has become one of research hotspot due to its advantage of low cost, simple device, good portability, etc. In recent studies, cymbal transducer is an important research direction of piezoelectric energy harvesting.At present, most of research on the cymbal transducer is parametric simulation analysis, which is lack of theoretical guidance and analysis. Firstly, in this paper, reasonable assumption is made by means of mechanical theory, based on which the mathematical model of cymbal transducer is established. Then FEA (Finite Element Analysis) static analysis is made on the cymbal transducer and four types of slotted cymbal transducers from voltage, stress, deformation. It comes to a conclusion that annular-slotted cymbal transducer is the best mode. Next, transient analysis is used to get the performance of slotted cymbal transducers under harmonic excitation, so the influence of slotted cymbal, loading ways, loading frequency on the performance of cymbal transducer is obtained. Then,taken the bonding layer of cymbal transducer in actual use into account, several measures of reducing the bonding layer stress are made and simulated.After that, for improving the current circuit, piezoelectric energy circuit based on Buck-Boost DC-DC conversion is designed and theoretically analyzed, the expression of output power and optimized parameters of the switch control signal are obtained. Then a hardware circuit is designed and the corresponding circuit simulation analysis is performed to verify the feasibility of the circuit and optimize the circuit.Based on the analysis above, three main parts of experiment are done to verify the model curve, to verify the advantages of slotted cymbal transducer and the annular slotted cymbal transducer over general cymbal transducer, to verify the feasibility of the experimental circuit. Through the experiments, it can be found that the output power increases with the excitation frequency, there exist matched load at different excitation frequency to get maximum output power. It reaches conclusions that the experimental curve is in line with the theoretical curve; both the ring slotted cymbal and the annular slotted cymbal can greatly improve output power; The output power of piezoelectric energy storage circuit based on Buck-Boost DC-DC conversion is concerned with excitation frequency, inductance, load matching, switching duty cycle, switching frequency, etc. High excitation frequency, big inductance, matched switching frequency can improve the output power.Finally, in order to obtain greater output power, an idea of composite cymbal transducer is put forward and three kinds of composite cymbal transducers are designed. Through theoretical analysis and finite element simulation, the composite cymbal transducers can improve output power and reduce the matched load. Among the three kinds of composite cymbal transducers multi-cymbal transducers can get the best result of energy harvesting.更多还原