低频激励下压电俘能器的簇发振荡和俘能效率分析
Bursting oscillation and energy capture efficiency analysis of piezoelectric energy harvester under low frequency excitation
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摘要: 环境振动能量是一种储量丰富、分布广泛的可再生清洁能源。通过能量采集技术,可将环境中的机械能转化为电能,为低功耗电子器件和无线传感网络自供电,是打破传统供电方式限制的有效解决途径之一。本文研究了低频激励下一种机械式非线性多稳态压电悬臂梁装置的簇发振荡和俘能效率。根据快慢动力学分析方法,将外激励项视为慢变量,作为调节快子系统动力学行为的控制参数,利用双参数分岔图,分析参数对系统的影响,得到系统发生簇发振荡的时间历程图、相图和转换相图,对系统的运动规律和分岔机理作了解释;采用数值仿真法分析了低频激励下系统的运动状态及俘能性能。结果表明,在低频激励下,系统存在簇发振荡现象,且系统为双稳态时具有较好的俘能特性。此外,引入时滞反馈抑制可以抑制簇发现象,保证系统稳定运行。Abstract: Environmental vibration energy is a kind of renewable and clean energy with abundant reserves and wide distribution. Through energy harvesting technology, the mechanical energy in the environment is converted into electrical energy to power low-power electronic devices and wireless sensor networks, which is an effective solution to break the limitations of traditional power supply methods. In this paper, the bursting oscillation and energy capture efficiency of a mechanical nonlinear multistable piezoelectric cantilever beam device are studied under low frequency excitation. By analyzing the potential energy of the system, it can be seen that the system has multi-stable characteristics with the change of system parameters. According to the fast and slow dynamic analysis method, the external excitation term is regarded as a slow variable and control parameter to adjust the dynamic behavior of the fast subsystem, and the time history diagram, phase diagram and transition phase diagram of the system are obtained. The motion state and energy capture performance of the system under low frequency excitation are analyzed by numerical method. The results show that the system exists bursting oscillation under low frequency excitation, and the system has good energy capture characteristics when the system is bistable. In addition, the time-delay feedback control can control the clustering phenomenon and ensure the stable operation of the system.