新型夹心式压电陶瓷复合变压器的特性

Characteristics of new sandwich piezoelectric ceramic ultrasonic composite transformer

提出一种新型多层复合夹心式纵向极化压电陶瓷变压器,并应用等效电路方法对压电振子的机电特性进行分析,推导出输入电阻、共振频率、反共振频率和电压增益的解析解,得出并分析了变压器第一、第二共振与反共振频率、机电耦合系数及电压增益与变压器的长度、负载电阻的关系。研究表明,一阶机电耦合系数在特定尺寸上和特定负载上均有最大值;一阶电压增益只在特定尺寸上存在最大值。将计算所得的共振频率、反共振频率与ANSYS模拟结果及实验测量结果进行比较验证,模拟结果及实验测量结果和理论计算值吻合。

A new type of the longitudinally polarized sandwich piezoelectric ceramic ultrasonic transformer was proposed. Using the equivalent circuit method the electromeehanical characteris- tics of the piezoelectric vibrator was analyzed. The analytical solutions of the input impedance, the resonance frequency, the anti-resonance frequency, the voltage gain were obtained. The rela- tionships of the resonance frequency, anti-resonance frequency, the electromechanical coupling coefficient, the voltage gain and the longitudinal lengths of the transformer, electric load resist- ance were obtained. The electromechanical coupling coefficient of first resonance mode has the maximum value in the certain size or electric load resistance. The voltage gain of first resonance mode has the maximum value in the certain size. The ANSYS simulation and the measured value of resonance frequency verified the analytical results. The results show that the simulation results and the experimental results agreed with the calculated results.