压电式振动发电机的建模及应用(英文)

Modeling and application of piezoelectric vibration-based power generator

振动式压电发电机是一种可为旋转机械故障诊断中的无线传感节点供电的微能源。本文设计了由压电悬臂梁、质量块和固定装置组成的振动式压电发电机,并建立了安装在恒速旋转机械上的悬臂梁式发电机的数学模型。分析了轴向分力对悬臂梁刚度和发电机频率的影响,在考虑悬臂梁受到轴向力影响的基础上,给出了发电机固有频率、输出电压和输出功率的公式。对一个安装于转动框架上的振动式压电发电机进行了测量,结果表明,当框架转动频率为14 .25Hz时,发电机的输出功率约为35μW,随着旋转机械转动频率偏离发电机固有频率,发电机的输出功率很快降低。

The piezoelectric vibration-based power generator is a promising MEMS electricity source to power wireless sensing nodes for the fault diagnosis of rotary machines. In this paper,a piezoelectric vibration-based power generator is designed and the mathematical model of the cantilever piezoelectric generator used in rotary mechines is established. Then,the effects of the axial extension force on the stiffness of the beam and the frequency of the generator are analyzed,and the formulas of the frequency, output voltage and output power of the cantilever piezoelectric generator are derived. The output property of the piezoelectric vibration-based generator fixed on a rotary frame is measured. Obtained results show that the maximum output power of the generator is about 35μW at the rotation frequency about 14.25 Hz. The output power decreases quickly when the rotation frequency deviates from the frequency of the generator