内置压电臂流致振动能量收集研究

Research of Built-in Piezoelectric Cantilever Flow Induced Vibration Energy Harvesting

为了减少压电臂在水中的阻尼以及绝缘和腐蚀等问题,本文提出一种内置悬臂梁的水下压电能量收集装置。首先对带有质量块的压电臂进行了自由振动衰减实验,确定压电臂的固有频率、阻尼比以及机电耦合系数,得到了压电臂固有频率与阻尼比随负载电阻变化的规律。之后在水槽中进行了流致振动能量收集实验,通过调节流速大小,在同一流速下更换不同阻值负载,得到输出电压及功率随流速及电阻的变化规律。结果表明输出电压随着负载电阻的增大而增大,在某一流速下会产生锁频现象,使得输出电压及功率最大。数据分析得到各电阻的最大功率出现在U=0.816 m·s^(-1)处,系统的最大功率出现在电阻值为680 kΩ时。

In order to reduce the piezoelectric cantilever damping,insulation and corrosion problem in the water,this paper proposes a built-in piezoelectric cantilever energy harvester. The free vibration test of the piezoelectric cantilever is conducted to determine the natural frequency,damping ratio and electromechanical coupling coefficient. The change laws of natural frequency and damping ratio with the piezoelectric cantilever load resistance are obtained. The flow induced vibration test in the water tunnel is conducted by adjusting load resistance value at the same flow velocity. The change laws of the output voltage and power with load resistance are obtained.The results show that the output voltage increases with the increase of load resistance. The output voltage and power are the largest when the frequency locking phenomenon occurred under a certain velocity. The maximum power is obtained when U is 0. 816 m·s^-1 and load resistance is 680 kΩ.