@article{Yu2025, 
author = {Jiaqi Yu and Wenming Guo and Feng Zhou and Linjin Xie and Mingmin Zhang and Lihua Cao},
title = {Novel Discrete-time Frequency-locked Loop for Three-phase Grid-connected Power Converters},
year = {2025},
journal = {Chinese Journal of Electrical Engineering},
volume = {11},
number = {1},
pages = {174-183},
keywords = {Grid-connected power converters, frequency-locked loop, nonlinear frequency estimation, harmonics rejection},
url = {https://www.sciopen.com/article/10.23919/CJEE.2025.000114},
doi = {10.23919/CJEE.2025.000114},
abstract = {A novel discrete-time frequency-locked loop (FLL) for three-phase grid-connected power converters that features rapid dynamic response and low computational cost is introduced. Firstly, a simplified nonlinear frequency-estimation model that leverages the inherent orthogonality of voltage signals in the αβ-frame, along with an optimal fixed-length delay, is proposed. Subsequently, a discrete-time FLL structure is developed based on this model. In addition, a convergence analysis and parameter design are presented. Finally, a comparative experiment with established methods is conducted, and the results demonstrate that the proposed FLL offers a faster dynamic response, requires fewer parameters to be tuned, ensures a smoother startup process, and maintains a relatively lower computational cost.}
}