压电与摩擦电复合型旋转能量采集动力学协同调控机制研究

低转速激励下能量采集性能差是目前制约旋转能量采集技术应用的瓶颈问题. 本文提出了动力学协同调控机制, 并用于调控系统的动力学行为, 可以使器件在低转速激励下有效工作, 提高了旋转能量采集系统的电学性能. 旋转刚度软化、非线性磁力、几何边界的协同调控既可以增加系统在低速下的振动位移以及压电材料的形变, 也可调控系统的最大位移, 使其振动可控并限制位移过大提高可靠性. 此外, 几何边界可以方便地集成摩擦纳米发电机, 实现压电与摩擦两种机电转换机制在振动和碰撞过程中协同发电, 有效利用空间和提高输出电能. 基于哈密顿原理建立了系统的机电耦合动力学模型并进行了实验验证. 实验结果表明系统能够在0~250 r/min的低转速范围内有效工作, 在转速为250 r/min时, 压电单元和摩擦纳米发电机的最大峰峰值电压分别为132 V和1128 V, 总平均功率为1426 μW. 本文提出的动力学协同调控机制为能量采集系统动力学和电学性能改进提供新的途径, 有益于促进自供能物联网技术的发展与应用. 

HYBRID PIEZOELECTRIC-TRIBOELECTRIC ROTATIONAL ENERGY HARVESTER USING DYNAMIC COORDINATED MODULATION MECHANISM

The poor performance of energy harvesting under low speed excitation is the bottleneck that restricts the application of rotational energy harvesting. In this paper, a dynamic coordinated modulation mechanism is proposed to modulate the dynamic behavior of the system, which can make the device work effectively under low speed excitation and achieve an enhanced electrical performance of the rotational energy harvesting system. The coordinated modulation of centrifugal-softening-nonlinear-magnetic-force-geometric-boundary can not only increase the vibration displacement of the system and the deformation of the piezoelectric material under low speed excitation, but also modulate the maximum displacement of the system when the vibration displacement is too large, so as to make the vibration controllable and improve the reliability. Moreover, the geometric boundary can easily integrate the triboelectric nanogenerator to realize the coordinated power generation of piezoelectric and triboelectric in the process of vibration and impact, which can make effective use of space and enhance the electrical performance. Based on Hamiltonian principle, the electromechanical coupling equation of the system is established and verified by experiments. The experimental results show that the system can work effectively in the speed range of 0?250 r/min. The P-P voltage of piezoelectric unit and triboelectric nanogenerator are 132 V and 1128 V, and the total average power is 1426 μW at the speed of 250 r/min. The dynamic coordinated modulation mechanism proposed in this paper provides a new method to improve the dynamic and electrical performance of energy harvesting system, and shows potential application prospects in the self-powered internet of things.