基于MEMS振动能量采集器的微电源设计与性能优化

发布时间：2019-03-23 15:11

【摘要】：传感器和网络等通讯技术日益成熟催生了物联网技术的快速发展,且物联网系统中包含着数以万计的传感器等待供能设备。目前的技术水平可以使这些设备的功耗低至微瓦,但传统的电池供电方式仍常常无法满足其持久、稳定、可集成、环境友好型等供能需求。本文设计了一种由振动能量转换模块、电能收集与存储模块以及升压模块三大模块组成的微电源,通过将微电源与物联网待供能设备集成而形成自供能设备,将能为物联网系统提供一种较为理想的供能解决方案。本文在前人研究成果基础上,先由微压电悬臂梁结构着手,考虑尺度效应影响因素,探讨了其力学性能变化规律;接着分别完成了能量转换模块、电能收集与存储模块和升压模块的设计与性能研究;最后针对现阶段能量采集器的不足之处,提出了一种新型的能量采集器结构设计方案,并进行了相关理论分析。论文的主要研究工作包括:(1)微悬臂梁动力学模型改进。针对微悬臂梁结构的压电式振动能量采集器考虑尺度效应影响,采用偶应力理论改进了微悬臂梁动力学模型,并结合实验测试结果充分说明了改进模型的准确性。(2)基于MEMS能量采集器的微电源设计与性能分析。在改进微悬臂梁式压电能量采集器模型的基础上,通过仿真分析并结合实测数据,探讨了其电能输出性能影响因素;进一步应用BQ25504和TPS61020芯片进行了电能收集与存储模块和升压模块的电路设计,并采用TINA对电能收集与存储模块以及升压模块的工作性能分别进行了分析。(3)微电源性能优化。针对微电源能量源头的能量采集器目前存在的高谐振频率和窄工作频带问题提出了一种n段梁和n个质量块组成的新型结构,并推导了其在外界激励下的位移响应以及输出电压的计算公式。以n=2和n=4的采集器为研究对象,分析了其产生的电荷量和电压随频率变化的关系,结果表明采集器的谐振频率实现了大幅度降低,且有效工作频带得到较大拓宽。
[Abstract]:The rapid development of Internet of things technology is spurred by the increasing maturity of communication technologies such as sensors and networks, and the Internet of things system contains tens of thousands of sensors waiting for energy supply equipment. The current technical level can make the power consumption of these devices as low as micro-watt, but the traditional battery power supply mode still can not meet its long-lasting, stable, integrated, environment-friendly and other energy requirements. In this paper, a kind of micro power supply is designed, which is composed of three modules: vibration energy conversion module, electric energy collection and storage module and boost module. By integrating the micro power supply with the Internet of things (IoT) equipment to supply energy, a self-energy supply device is formed. It will provide an ideal solution for the Internet of things system. On the basis of previous research results, this paper begins with the structure of micro-piezoelectric cantilever beam, considering the influence factors of scale effect, and probes into the variation rule of its mechanical properties. Then, the design and performance of the energy conversion module, the power collection and storage module and the boost module are completed. Finally, aiming at the deficiency of energy collector at present, a new structure design scheme of energy collector is put forward, and the related theory is analyzed. The main research work in this thesis is as follows: (1) the dynamic model of micro-cantilever beam is improved. Considering the influence of scale effect on the piezoelectric vibration energy collector of micro-cantilever structure, the dynamic model of micro-cantilever beam is improved by using the coupled stress theory. The accuracy of the improved model is fully demonstrated by the experimental results. (2) the design and performance analysis of the micro-power supply based on the MEMS energy collector. On the basis of improving the model of micro-cantilever beam piezoelectric energy collector, the influencing factors of its power output performance are discussed through simulation and analysis combined with the measured data. Furthermore, the circuit design of power collection and storage module and boost module is carried out by using BQ25504 and TPS61020 chips, and the performance of power collection and storage module and boost module are analyzed by TINA. (3) the performance optimization of micro-power supply is given. Aiming at the problem of high resonant frequency and narrow operating frequency band of the energy collector at the energy source of micro-power source, a new structure consisting of n-segment beam and n mass blocks is proposed in this paper. The formulas of displacement response and output voltage under external excitation are derived. In this paper, the relationship between the charge and the voltage of the collector is analyzed. The results show that the resonant frequency of the collector is greatly reduced, and the effective frequency band is broadened. The results show that the resonant frequency of the collector has been greatly reduced and the frequency band of the collector has been broadened greatly with the change of the voltage and the amount of charge generated by the collector.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM619

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