螺旋形压电发电装置的发电性能研究

发布时间：2018-02-04 07:20

本文关键词： 压电发电结构设计螺旋形基板实验研究有限元分析结构优化　出处：《扬州大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着MEMS技术、无线电技术的飞速发展,手机、数码相机、笔记本电脑等电子产品极大的丰富和方便了人们的生活和工作。但在能量供给方面,依然采用着传统的供能方式,即利用化学能电池作为主要的能量供应装置。虽然化学能电池有其方便之处,但需要经常更换、浪费材料、污染环境、回收困难等问题日益突出,迫切需要寻求新的供能装置。压电发电装置是最为常用的振动式能量收集器,主要通过压电陶瓷的正压电效应,将振动能转化为电能。由于该装置具有结构简单,加工方便,不会向环境中排放有毒有害物质,限制条件少等优点,已经成为一种新型的节能环保发电装置。压电发电装置所采集到的能量与振动的幅值、频率、几何尺寸有关,其中,频率是个至关重要的因素。当振动频率接近装置的谐振频率时,振幅最大,获取的电压和功率可以达到峰值。因此,压电发电装置的结构设计与所涉及的应用环境是密切相关的,所设计的结构在使用时必须基于振动频谱的基本特性。目前主要是通过延长梁的长度和在末端增加质量块来降低结构的谐振频率,但延长梁的长度在微机电系统中显然是不合理的,没有足够的空间,增加质量块来降低结构的谐振频率其效果也同样有限。这样,就会大大降低换能器的换能效率。针对此问题,本文提出了一种可以有效降低谐振频率,且无需大幅度增加梁长度的新型几何结构装置。通过将直梁改为螺旋形,并在其上布置可以滑动的质量块,通过质量块的滑动可以很方便地调节装置的固有频率,解决了现有压电发电装置谐振频率高、外界振动频率与装置的固有频率不匹配等问题,大大提高了压电发电装置的发电能力。本文首先设计了新型的螺旋形基板,然后制作了螺旋形压电发电装置实物模型,并搭建试验平台对装置的固有频率和开路输出电压进行了实验测试,同时对发电装置进行了模态分析和动态发电特性分析。实验测试结果表明,螺旋形压电发电装置的固有频率较低,发电装置上可以粘贴多个发电电压都较大的压电片。然后基于ANSYS 14.5有限元软件,建立了螺旋形压电发电装置的有限元分析模型,对装置进行了静力分析、模态分析及压电耦合分析,并将有限元分析计算结果和实验测试结果进行比较,经比较发现,其固有频率和发电电压的相对误差均不超过10%,从而验证了有限元分析计算模型的正确性。在此基础上,利用有限元软件对不同结构参数的螺旋形压电发电装置进行模拟仿真,通过改变装置的配重、长度即圈数、宽度、层间距及厚度等参数,来分析其对装置的固有频率与发电电压的影响规律,以便设计出适应环境的最优化结构模型,从而获得具有最佳发电性能的压电发电装置。
[Abstract]:With the rapid development of MEMS technology and radio technology, mobile phone, digital camera, notebook computer and other electronic products have greatly enriched and facilitated people's life and work. But in the aspect of energy supply. Chemical energy battery is still used as the main energy supply device. Although chemical energy battery has its convenience, it needs to be replaced frequently, waste materials and pollute the environment. The difficulty of recovery is becoming more and more serious, so it is urgent to find new energy supply devices. Piezoelectric power generation device is the most commonly used vibratory energy collector, mainly through the piezoelectric ceramic positive piezoelectric effect. The device has the advantages of simple structure, convenient processing, no discharge of toxic and harmful substances into the environment, and less limiting conditions. It has become a new type of energy saving and environmental protection power generation device. The energy collected by piezoelectric power generation device is related to the amplitude, frequency and geometric size of vibration. Frequency is a crucial factor. When the vibration frequency is close to the resonant frequency of the device, the amplitude is maximum and the voltage and power obtained can reach the peak. The structure design of piezoelectric power plant is closely related to the application environment involved. The design of the structure must be based on the basic characteristics of the vibration spectrum. At present, the main way to reduce the resonant frequency of the structure is to extend the length of the beam and increase the mass block at the end. However, it is obviously unreasonable to extend the length of beam in MEMS, there is not enough space, and the effect of increasing mass block to reduce the resonant frequency of the structure is also limited. The efficiency of the transducer will be greatly reduced. In order to solve this problem, this paper proposes an effective method to reduce the resonant frequency. By changing the straight beam into a spiral shape and placing a slidable mass block on it, the new geometric structure device does not need to increase the length of the beam by a large margin. The natural frequency of the device can be easily adjusted by the slippage of the mass block, which solves the problems of high resonance frequency of the existing piezoelectric power generation device and the mismatch between the external vibration frequency and the natural frequency of the device. Firstly, a new spiral substrate is designed, and then the physical model of the spiral piezoelectric power generation device is made. The natural frequency and open circuit output voltage of the device are tested on the test platform, and the modal analysis and dynamic generation characteristic analysis are carried out. The experimental results show that. The natural frequency of the spiral piezoelectric power generation device is low, and the piezoelectric plates with larger generation voltage can be pasted on the generating device. Then, the finite element software based on ANSYS 14.5 is used. The finite element analysis model of spiral piezoelectric power generation device is established. Static analysis, modal analysis and piezoelectric coupling analysis are carried out, and the results of finite element analysis and experimental test are compared. By comparison, it is found that the relative error of the natural frequency and the generation voltage is not more than 10, which verifies the correctness of the finite element analysis and calculation model. The finite element software is used to simulate the spiral piezoelectric power generation device with different structure parameters. By changing the weight of the device, the length is the number of cycles, the width, the interval between layers and the thickness of the device. In order to design the optimal structure model to adapt to the environment, the piezoelectric power generation device with the best generation performance is obtained by analyzing its influence on the natural frequency and generation voltage of the device.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM619

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