用于移相干涉的高精度可伸缩PZT驱动电源技术

High-precision retractable PZT driving power technology for phase-shifting interferometry

针对现有的三压电陶瓷移相器难以驱动大口径参考镜进行移相干涉测量的问题,设计了一种用于被测镜单压电陶瓷驱动移相干涉测量系统的高精度压电陶瓷移相器驱动电源。电源采用误差放大式结构,根据输入信号与输出采样的偏差,通过比例作差与光耦隔离等环节输出控制信号,进而控制MOSFET的导通状态调整充放电电流,控制由倍压整流电路生成的直流高压源进行输出,实现对驱动电源输出电压的稳定控制。实验表明其高精度压电陶瓷驱动电源具有在-600~+600V范围内输出连续可调电压的能力,且纹波小于20mV,线性度和精确度高,稳定性好,可实现压电陶瓷的可伸缩精确移相,满足被测镜移相干涉测量系统进行大口径被测镜高精度面形测量的要求。

Aiming at the problem that the existing 3-PZT phase-shifter is difficult to drive the large-aperture reference mirror for phase-shifting interferometry, a high-precision piezoelectric ceramic driving power supply for the measured element phase-shifting interferometry system is designed. The power supply that adopts error-amplification structure outputs the control signal through the proportion difference and optocoupler isolation according to the deviation between the input signal and the output sampling, and then controls the conduction state of MOSFET, adjusts the charge and discharge current, and controls the output of the DC voltage generated by the voltage doubling rectifier circuit, so as to realize the stable control of the output voltage of the driving power supply. Experiments show that the high-precision piezoelectric ceramic driving power supply has the ability that outputs continuously adjustable voltage in the range of-600~600 V, and has ripple less than 20 mV, high linearity and accuracy, good stability. It can realize the retractable and accurate phase-shifting of piezoelectric ceramics, and can meet the requirements of the surface measurement of the large-aperture measured mirror by the measured element phase-shifting interferometry system.