基于交叉解耦双复系数滤波器的频率自适应锁相环

锁相环PLL(phase-locked loop)是控制逆变器实现并网同步的重要方法之一.针对准1型锁相环QT1-PLL(quasi-Type-1 PLL)在电网电压频率偏移时抗干扰能力不佳、导致检测频率和相位误差较大的问题,本文提出一种新型的基于交叉解耦双复系数滤波器DCCF(double complex coeff...

Frequency Adaptive Phase-locked Loop Based on Crossing-Decoupling Double Complex Coefficient Filter

Phase-looked loop(PLL)is one of the important methods to control an inverter and achieve grid-connected synchronization.Considering that the quasi-Type-1 PLL(QT1-PLL)has a poor anti-disturbance capability under fre?quency offset of grid voltage,which leads to large errors in detected frequency and phase estimation,a novel crossingdecoupling double complex coefficient filter(DCCF)-based QT1-PLL(DCCF-QT1-PLL)is proposed in this paper.A crossing-decoupling DCCF with frequency feedback loop is used as the pre-filtering stage of QT1-PLL,and a moving av?erage filter(MAF)with 0.0033 s window length is used as the in-loop filtering stage of DCCF-QT1-PLL.As a result,a small-signal model of DCCF-QT1-PLL is established,and its design parameters are obtained.The structure of the pro?posed DCCF-QT1-PLL can eliminate the grid voltage imbalance and harmonic component,thereby achieving frequency adaptation.A simulation model is built in the Matlab/Simulink platform,and simulation results show that the structure of DCCF-QT1-PLL has capabilities of frequency adaptation and stronger filtering.