压电振动电阻尼与能量转换特性研究

Characteristic Research of Electrical Damping and Energy Conversion for Piezoelectric Vibration

根据压电构造方程和振动原理,建立压电振动能量收集的耦合场动力学模型。详细推导电阻尼与外接电阻和机电耦合系数之间的数学关系,并揭示外接电阻对系统固有弹性的作用效果。通过数值模拟研究电阻尼特性对谐振频率、振动幅值和功率的影响关系,并从能量转换效率的角度分析优化电阻与最大输出功率的关系。分别对多种外接电阻条件下压电梁的输出电压及功率进行实验测试,实验结果表明,电阻尼导致压电梁的谐振频率发生偏移,其大小与外接电阻值成正比,而且在外接优化电阻时输出功率最大。

The electromechanical coupling dynamic model of piezoelectric energy harvesting system is established based on the piezoelectric structural equation and vibration principle.With detailed reduction of the mathematical relationship between electrical damping and external resistance as well as electromechanical coupling coefficient,the effect of the external resistance for the proper stiffness of system is revealed.The influences of the electrical damping characteristics on the resonant frequency,vibration amplitude and output power are analyzed through numerical cheater,and the relationship between the optimal resistance and maximum output power is analyzed according to the energy conversion efficiency.The output voltage and power of the piezoelectric beam are tested with various external resistances,the experimental results indicate that the electrical damping causes shifts to external resistance and the shifts,which are directly proportional to the external resistance value.Moreover,the output power achieves maximum value with optimal external resistance.