并联非线性压电俘能系统及其俘能特性的研究

发布时间：2018-06-05 21:16

本文选题：并联非线性压电俘能系统 + 俘能效果　；参考：《西南交通大学》2017年硕士论文

【摘要】：振动源无处不在。压电振动俘能器是当前能量收集的研究热点之一。双稳态非线性压电俘能器虽然克服了线性压电俘能器存在的问题,但仍存在输出电流过小,难以高效地为电池等储能设备充电的问题。受线性并联压电俘能器设计的启发,本文提出一种并联非线性压电俘能系统,并进行了研究。在建立了并联非线性压电俘能系统的动力学方程之后,采用数值计算的方法,对系统的俘能效果进行了研究,得出了一些可使俘能系统获得较好俘能效果、供设计时参考的研究结论。本论文的主要研究工作和结论如下:1.建立了并联非线性压电俘能系统的物理结构及其动力学模型。该系统的动力学分析模型可由单个双稳态非线性俘能器方程的耦合叠加得到。对系统的动力学分析模型的数值仿真结果表明:当并联的悬臂梁中的一个为周期运动,其他的梁也一定是周期运动;而当一个梁为混沌运动,其他的梁要么为混沌运动,要么为拟周期运动。在特定的系统参数区域内,并联俘能系统的平均输出功率为单个俘能器平均输出功率与并联数的乘积,输出电流也为单个俘能器输出电流与并联数的乘积。这就说明并联系统具有一定的优点。2.研究发现,并联非线性压电俘能系统也会出现"跳频现象"。当发生"跳频现象"的时候,在一个极小的频率范围内,悬臂梁振动先从阱间的周期运动转变为阱间的拟周期或混沌运动中,再从阱间的拟周期或混沌运动转变为阱内的多周期运动,然后就稳定在阱内作周期运动。经分析发现,为避免"跳频现象",系统的参数至少应使系统处于混沌边缘的出现混沌的区域一侧,即由Melnikov解确定的混沌区域。进一步的研究发现,并联数的变化对混沌边缘的影响不明显;而等效非线性刚度对混沌边缘的影响却比较明显。3.双稳态非线性压电俘能器中存在明显的、夹杂在两个混沌运动区域之间周期运动区域。该区域的宽度称为周期运动宽度。将系统在一段无量纲频率范围之内能够保持稳定的、没有或只在极少频率下俘能效果指标P出现波动的频率宽度称为有效工作频带宽度。研究表明:系统集总参数对周期运动宽度、有效工作频带宽度有明显的影响,但并联数对周期运动宽度、有效工作频带宽度没有明显的影响。只有当集总参数相同的时候,n并联非线性压电俘能系统的周期运动宽度和有效工作频带才不会减小,系统具有较好的俘能效果。
[Abstract]:Vibration sources are everywhere. Piezoelectric vibratory energy capture device is one of the research hotspots in energy collection. Although the bistable nonlinear piezoelectric energy capture device overcomes the problem of linear piezoelectric energy capture device, it still has the problem that the output current is too small and it is difficult to charge energy storage equipment such as battery efficiently. Inspired by the design of linear parallel piezoelectric energy capture, a parallel nonlinear piezoelectric energy capture system is proposed and studied in this paper. After the dynamic equation of the parallel nonlinear piezoelectric energy capture system is established, the energy capture effect of the system is studied by using the numerical calculation method, and some results are obtained that can make the energy capture system obtain better capture energy effect. Conclusions for reference in design. The main work and conclusions of this thesis are as follows: 1. The physical structure and dynamic model of a parallel nonlinear piezoelectric energy capture system are established. The dynamic analysis model of the system can be obtained by the coupled superposition of a single bistable nonlinear energy capture equation. The numerical simulation results of the dynamic analysis model of the system show that when one of the parallel cantilever beams is periodic motion, the other beams must also be periodic motion, while when one beam is chaotic motion, the other beams are either chaotic motion. It is either quasi periodic motion. In a specific system parameter region, the average output power of the parallel energy capture system is the product of the average output power of a single energy capture device and the number of parallel connections, and the output current is also the product of the output current of a single energy capture device and the number of parallel connections. This shows that the parallel system has some advantages. It is found that frequency hopping also occurs in parallel nonlinear piezoelectric energy capture systems. When the "frequency hopping phenomenon" occurs, in a minimal frequency range, the vibration of the cantilever beam changes first from the periodic motion between the wells to the quasi-periodic or chaotic motion between the wells. Then the quasi-periodic or chaotic motion between the wells is transformed into the multi-periodic motion in the well, and then the periodic motion is stabilized in the well. It is found that in order to avoid "frequency hopping phenomenon", the parameters of the system should at least make the system at one side of the chaotic region on the edge of chaos, that is, the chaotic region determined by the Melnikov solution. It is found that the influence of parallel number on chaotic edge is not obvious, but the effect of equivalent nonlinear stiffness on chaotic edge is obvious. The bistable nonlinear piezoelectric energy capture has obvious inclusions in the periodic motion region between two chaotic motion regions. The width of the region is called the width of periodic motion. The effective operating band width is called the frequency width of the system which is stable in a dimensionless frequency range and fluctuates without or only at very few frequencies. The results show that the lumped parameters of the system have a significant effect on the width of the periodic motion and the effective working band, but the number of parallel connections has no obvious effect on the width of the periodic motion and the effective working band. Only when the lumped parameters are the same, the periodic motion width and the effective frequency band of the nonlinear piezoelectric energy capture system in parallel are not reduced, and the system has better energy capture effect.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM619

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