三相数字锁相环的原理及性能

摘要

分析了三相锁相环的基本原理、特性及各种输入情况下锁相环的输出性能.通过理论推导,在三相输入信号存在直流偏移、不对称、谐波等干扰情况下,分析了三相锁相环的检测相位误差,得出谐波的含量.并通过仿真研究,验证了三相输入信号存在直流偏移、不对称、谐波等干扰情况下,仿真结果与理论推导一致.并对相位突变和频率突变的情况进行了仿真研究,说明在相位和频率发生变动时三相锁相环仍能有效地锁定相位,能够满足系统变频的要求.%This paper analyzes the fundamental principle and performance of three-phase phase-locked loop, and the harmonic component in variable situations. It deducts the error influence on three-phase locked phase when the three-phase input signals are offsetting, unbalanced or with harmonics. The theoretical conclusions are confirmed by detailed simulations under the situations, such as offsetting, unbalance, harmonic, phase-abrupt and frequency-abrupt. The simulation results prove that the three-phase phase-locked loop can work well in disturbance situation and variable frequency system when the frequency of the inputs is variable.