Design-Oriented Transient Stability Analysis of Grid-Connected Converters: A Comparative Study of Analysis Methods
Chao Charles Liu, Chi K. Tse, Meng Huang, Zhenxi Wu, Hua Han, Jingxi Yang
Abstract
Transient stability analysis of grid-connected converters can provide guidance for practical design. Previous studies have summarized monotonic relationships between stability and parameters. Given the complex nonlinear behavior of converter-based systems, these monotonic relationships are incomplete. In this article, design guidelines in the form of feasible parameter ranges are developed. Sensitivity analysis and bifurcation diagrams are utilized to derive feasible parameter ranges from typical stability analysis methods, including time-domain simulation, energy-based methods (manually derived and algorithmically searched), and bifurcation analysis. It is found that different analysis methods may provide equivalent design guidelines due to the similar sensitivity patterns identified by these methods. Furthermore, we reveal that the change in the sensitivity patterns can be induced by the bifurcation behavior of grid-connected converters. Therefore, the qualitative differences between the stability analysis methods are determined by their ability to capture the various bifurcations crucial for determining transient stability. Our results show different levels of consistency between the analysis methods. The findings are verified by laboratory experiments.