基于Class-D功率放大的超声波电动机驱动方案

Driving Scheme for the Ultrasonic Motor Based on Active Filter and Class-D Power Amplifier

研究了一种基于有源滤波器和D类(Class-D)功率放大的新型高性能超声波电动机驱动方案。基于有源滤波器设计了频率、幅值、相位可调的正弦信号发生器,设计了基于Class-D功放的功率放大和匹配电路。通过匹配电路仿真分析验证了该方案的设计思想。在现有旋转行波超声波电动机上将所提方案与传统脉宽调制(PWM)逆变式驱动方案进行了对比实验,对两种驱动电路产生的波形进行了频谱分析。实验结果显示,与PWM逆变式驱动方案相比,基于有源滤波器和Class-D功率放大方案的驱动波形谐波分量较少,能量损耗较小,同时缩小了驱动器体积,有利于实现超声波电动机驱动器的小型化。

A new driving scheme for ultrasonic motor based on active filter and the Class-Daudio power amplifier was studied. Based on active filter, a sinusoidal signal generator was designed, the frequency, amplitude and phase of which are adjustable. The power amplifier and matching circuit based on the Class-Daudio power amplifier were designed. The matc-hing circuit simulation analysis verifies the mentality of designing of the presented scheme. The contrast experiments be-tween the presented scheme and the traditional pulse-width modulation (PWM) inverter driving scheme were conducted on the current rotating travelling wave ultrasonic motor. Fast Fourier transform(FFT) analysis was performed on the waveform spectrum generated by two driving circuits. These experiments reveal that compared with the PWM inverter driving scheme, the Class-D power amplifier scheme has shown better performance in harmonic components and energy efficiency. The pro-posed schemeis in favor of the miniaturization of the ultrasonic motor driver.