Angle Stability Analysis for Voltage-Controlled Converters

Power-electronics-based voltage-source converters (VSCs) keep increasing in modern electrical systems. As a branch of stability problems, angle stability is significant for an electrical system. Based on small disturbance analysis and time scale decomposition perspective, this paper proposes a criterion to analyze the quasi-steady angle stability and the direct current side stability for VSCs. The operating limit and the angle instability mechanism are revealed, which is generally applicable to the voltage-controlled converters. During the analysis, the influence of the parameters on angle stability is studied. Furthermore, the difference on instability mechanism between power electronic converters and synchronous generators is explained in detail. Finally, experiment results with corrective actions verify the analysis.