Transient Synchronous Stability Analysis and Control Improvement for Power Systems with Grid-Following Converters

Amid the global transition towards sustainable energy, the increasing integration of power sources equipped with grid-following (GFL) voltage source converters (VSCs) into power systems has significantly impacted transient synchronous stability. How to analyze the transient synchronous mechanism of power systems with GFL and how to fully utilize GFL to enhance the transient synchronous stability are critical challenges. Therefore, based on the extended equal area criterion (EEAC), the influence mechanism of the transient voltage stability on the transient synchronous stability of multi-machine power systems is analyzed. Furthermore, an explicit power angle equation is derived, incorporating the distribution location and active power characteristics of GFL, to explain their impact on the transient synchronous stability between synchronous generators (SGs). Inspired by the above insights, an improved control strategy of GFL is proposed for transient stability enhancement. The proposed strategy can effectively accelerate the voltage recovery speed and enhance the transient synchronous stability under different coherence grouping scenarios. Finally, the correctness of the mechanism analysis and the effectiveness of the proposed control strategy are validated on the simplified system of a real power grid using the PSCAD platform.