单振子二自由度超声电机驱动电源

Driving power supply for two-degree-of-freedom ultrasonic motor with single vibrator

设计了用于平板形单振子二自由度超声电机的驱动电源,并针对驱动电源电流负荷较大,输出功率利用率不高的问题,提出了优化驱动性能的措施。该电源利用压控振荡器产生正弦小信号,经高压及功率放大后得到较高的驱动电压及较大的驱动电流实现电机驱动。根据压电振子等效电路模型及工作特性,采取与超声电机并联电感的方法优化了电源驱动性能。制作了驱动电源样机,并对输出性能及优化效果进行了测试。测试结果表明:设计的电源驱动电压及频率可独立连续调节,可输出理想的正弦信号波形;在49.127 kHz、49.756 kHz两种频率下,接超声电机负载时,最大输出电压分别为176.0 V及171.2 V;超声电机并联1.442 mH电感后,电源驱动电流可减少至原来的7.27%和7.41%,功率因数可提高至0.968和0.9550。得到的结果显示,设计的电源满足超声电机驱动要求,采取的优化措施在减小电源电流负荷及提高电源输出功率利用率方面效果明显。

A driving power supply was designed for the two-degree-of-freedom （2-DOF） ultrasonic mo- tor with a single plate-shaped vibrator. According to the heavy current burden and 10w power utiliza- tion of the driving power supply, a method for optimizing the driving performance was proposed. The power supply used a voltage-controlled oscillator to generate a small sine signal, and applied a high- voltage and power amplifier to produce a higher driving voltage and a larger driving current. Accord- ing to equivalent circuit and operating characteristics of piezoelectric vibrator, the ultrasonic motor was connected with an appropriate inductor in parallel to optimize the driving performance of the driv- ing power supply. A prototype of driving power supply was made and its output performance and opti- mization effect were tested in an experiment. Experimental results show that the control variables of ultrasonic motor in power supply-driving voltage and frequency can be adjusted independently and con- tinuously, and an ideal waveform of sine signal is obtained. When the power supply is loaded by the 2-DOF ultrasonic motor in frequencies of 49. 127 kHz and 49. 756 kHz, the maximum output voltages are 176.0 V and 171.2 V. When the ultrasonic motor is connected with a 1. 442 mH inductor in paral- lel, driving current can be reduced to 7.27% and 7.41%, and the power factor can reach 0. 968 and 0. 955 0, respectively. The power supply designed meets the driving requirements of the ultrasonic motor, and optimization method on reducing current burden and improving power utilization has good results.