Phase-locked loop control strategy based on improved dual second-order generalized integrator in two-phase stationary coordinate system
HAN Yixin1, ZOU Fumin1, HOU Jun2, ZHANG Qing2
1. School of Electronic, Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350118; 2. Fujian Xingyun Electronics Co., Ltd, Fuzhou 350000
Abstract：Due to the widespread integration of distributed renewable energy sources and diverse load into the power grid, the conventional synchronous reference frame-phase-locked loop (SRF-PLL) structure fails to accurately track grid parameters such as phase and frequency under complex grid conditions. Therefore, this paper proposes a novel phase-locked loop control strategy based on an improved double second-order generalized integrator (DSOGI) in the two-phase stationary coordinate system. Firstly, a cascaded resonant filter is employed to address odd harmonics in the low-frequency range. Additionally, a DC bias filter branch is incorporated based on second-order generalized integrator quadrature signal generator (SOGI-QSG) to mitigate DC disturbances, achieve decoupled separation of positive and negative sequence voltages, and optimize suppression of high-frequency harmonics. Subsequently, a αβ phase-locked loop (PLL) structure is constructed to enhance dynamic response performance by leveraging the small signal control model and improve phase-locking accuracy. Finally, the efficacy of the enhanced phase-locked loop control strategy is validated through comparative simulation using Matlab/Simulink.
2024, Vol. 25 
