基于二阶带通滤波器的单相锁相环技术研究

Research on Single-phase Phase Locked Loop Technology Based on Second-order Bandpass Filter

摘要:

并网系统中，由于存在大量电力电子器件，导致并网逆变器输出的电压中存在直流分量和高频谐波，传统锁相环的环路滤波器难以完全滤除输入信号的谐波，将在锁相环输出信号中产生相位偏移。针对这一现象，本文构造一个二阶带通滤波器（Biquad filter，BF），有效抑制输入电压信号中直流分量和高频谐波，锁相环中正交信号通过构造二阶广义积分器（SOGI）来获得，文中对二阶带通滤波器特性进行分析，设计了双二阶带通滤波器参数，最后，通过Matlab/Simulink软件对包含直流分量、高频分量、畸变、跳变等情况的电压信号进行仿真，仿真结果表明基于二阶带通滤波器的锁相环能够很好抑制直流分量和高频分量，有效消除因参数设置不合理产生的相位偏移。

Abstract:

In the grid-connected system, due to the existence of a large number of power electronic devices, there are DC components and high-frequency components in the voltage output by the grid-connected inverter. The loop filter of the traditional phase-locked loop is difficult to completely filter the harmonics of the input signal. A phase shift occurs in the output signal of the phase-locked loop. In response to this phenomenon, this paper constructs a second-order band-pass filter (Biquad filter, BF) to effectively suppress the DC component and high-frequency harmonics in the input voltage signal. The quadrature signal in the phase-locked loop is constructed by constructing a second-order generalized integrator ( SOGI). The characteristics of the second-order bandpass filter are analyzed in the article, and the parameters of the second-order bandpass filter are designed. Finally, through the Matlab/Simulink software, the conditions including DC components, high-frequency components, distortion, jumps, etc. The simulation results show that the phase-locked loop based on the second-order band-pass filter can well suppress the DC component and high-frequency component, and effectively eliminate the phase shift caused by unreasonable parameter settings.