基于可变遗忘因子的递推最小二乘法锁相环研究

Research on PLL Based on Recursive Least Square Method With Variable Forgetting Factor

电网电压相位角的准确获得,是变流器并网运行关键的指标之一。当三相电压出现频率、幅值或者相位突变时,传统锁相环算法往往出现相角估计不准,动态性能较差等问题。本文提出基于可变遗忘因子的递推最小二乘法锁相环算法,该方法通过对电网电压不平衡引起的相电压的角度、幅值和偏移量进行实时补偿来检测相角,实现提高系统鲁棒性和系统稳定性的目的。通过仿真和实验加以证明,结果表明该算法可以有效提高锁相环的精度和可靠性,提高系统的抗干扰能力。

Accurately obtaining the phase angle of the grid voltage is one of the key indicators for the grid-connected operation of the converter.When the frequency,amplitude or phase of the three-phase voltage changes suddenly,traditional phase-locked loop algorithms often have problems such as inaccurate phase angle estimation and poor dynamic performance.This paper proposed a recursive least squares-based phase-locked loop algorithm based on a variable forgetting factor.This method detectd the phase angle by real-time compensation of the phase voltage angle,amplitude,and offset caused by the voltage imbalance in the power grid to improve the robustness and stability of the system.It is proved through simulation and experiments that the algorithm can effectively improve the accuracy and reliability of the phase-locked loop,and improve the anti-interference ability of the system.