基于最少拍无波纹算法的高精度动态标准源反馈控制

Feedback control of high precision dynamic standard source based on ripple-free deadbeat algorithm

针对在高动态精度电压电流标准源反馈控制中,因系统纯滞后时间大于控制节拍而导致系统不稳定的问题,研究将最少拍无波纹控制技术应用于动态标准源控制的方法.通过实验获取系统阶跃响应和纯滞后时间,进而辨识系统传递函数,在此基础上设计出针对高精度动态电压电流标准源的最少拍无波纹控制器.通过仿真验证了方法的有效性,并在实际的硬件系统中进行了实验验证,得到了系统动态性能指标.实验表明:采用最少拍无波纹算法的动态标准源输出正弦信号,1Hz正弦输出时,幅值不确定度达到量程的±6.7×10-6以下,总谐波失真达到0.01%以下,证明了最少拍无纹波控制算法的有效性.

Closed loop feedback method is used in the voltage/current source instrument to achieve the high AC precision. If the pure time delay of the system is larger than one control beat, the feedback system would be unstable. A ripple-free deadbeat algorithm was proposed for the feedback control of the high dy- namic precision voltage/current source instrument. Firstly, the pure time delay and the step response were measured precisely via experiment. Then, the transfer function was identified. And finally, a kind of ap- propriate ripple-free deadbeat controller was designed based on the transfer function for the instrument. The effectiveness of the control algorithm was verified by simulation. After that, some experiments were applied on the instrument, and the dynamic performance was gained. The experimental results showed that when the dynamic standard adopts the ripple-free deadbeat and outputs 1 Hz sinusoidal signal, the amplitude uncertainty of the output signal can be less than ±6.7×10^-66 of range, and the total harmonic distortion can be less than 0.01 %.