Stability Analysis of PLL-Type Grid-Connected Converter Based on The Perturbation Method

In recent years, the widespread adoption of phase-locked loop type grid-connected converters has presented new challenges for transient stability and small-signal stability analysis of power systems. Therefore, it is crucial to develop effective methods for analyzing the stability of converters-interfaced power systems. In this paper, a generalized swing equation model of a single converter connected to an infinite bus is derived. Then, approximate analytical solutions for the model are obtained. The accuracy of the analytical solutions is verified through simulation analysis. Based on the analytical solution, a parameter stability analysis is performed to gain further insights on both transient and small-signal stability. Finally, the proposed results are verified using several examples, demonstrating the accuracy and effectiveness of the suggested methods.