基于锁相环与双A/D的交流采样技术及其应用

AC Sampling Technology and Its Application Based on PLL and Double A/D

为了保证对电力系统的实时监控、调度,需要对电力参数进行交流采样;介绍了电力系统参数交流采样的设计思想,对频率跟踪电路进行了分析,提出了由锁相环CD4046和双MAX125构成的硬件解决方法,并给出了由CD4046构成的频率跟踪电路图以及双MAX125与80C196KC单片机的接口设计电路,解决了电力系统中多路电压、多路电流的交流采样问题,保证电网频率变化时采样数据的精度和稳定性;该采样算法可以应用于多种场合,具有一定的实用和推广价值。

In order to guarantee the real time control over power system, AC sampling for power system parameters is needed. A designing method of AC sampling is presented, and the frequency tracking circuit is analyzed. It presents a method of hardware solution using phase-locked loop CD4046 and double MAX125 chip. The frequency tracking circuit based on CD4046 and the interface circuit between double MAX125 and 80C196KC is developed to solve the AC sampling for multiple voltage and current signals in power system. Then the accuracy and stability is guaranteed when the distortion exists in the frequency of the system. The way of this AC sampling can be applied in many situations and has some practical utility.