中文摘要：

由于超声波电机运转时自身参数会发生变化,使用LLCC驱动电路可以有效克服由电机运转时自身参数变化引起的输入电压变化,使电机的输入电压稳定为某一数值,基于此,对超声波电机的LLCC驱动电路进行了初步的探讨。文中描述了超声波电机的单相等效模型,分析了超声波电机LLCC驱动电路的特性,并在此基础上建立其数学模型,并证明了LLCC驱动电路不受频率、品质因数和负载变化的影响,通过仿真计算LLCC驱动电路的幅频特性和相频特性,以及参数变化时LLCC驱动电路的幅频特性和相频特性。实验结果证明在不同驱动频率下驱动电路的输出波形保持一致,且基本相等。实验结果也验证了此电路的有效性。

英文摘要：

The dynamic characteristic of USM（ultrasonic motor） will be changed greatly when USM rotates and is greatly influenced by the variation in the quality of the motor, while the LLCC driving circuit can generate a geometric frequency which can make the LLCC circuit not be influenced by the variation in quality of the motor. Based on the above facts, a LLCC resonant circuit is implemented in this paper for USM driving. Firstly a single phase equivalent model of USM is presented. Then the operating princilple of the proposed driving circuit is introduced. And on this basis, the mathematical model is established. Then LLCC driver circuit is proven that it will not be affected by frequency, quality factor and change of load. Simulation results show that amplitude and phase plots of LLCC resonant circuit are from 20 to 80 kHz and from 39 to 45 kHz respectively. Also amplitude and phase plots of LLCC circuit are simulated with changing parameters. Finally output voltage waveforms of driving circuit under driving frequencies with different values are provided to demonstrate the effectiveness of the proposed circuit.