Transient Stability Analysis of Grid‐following and Grid‐forming Converters

Transient stability has been a fundamental concern in conventional power systems dominated by synchronous generators (SGs), where stability is primarily determined by the inherent power–angle characteristics and mechanical dynamics. With the rapid proliferation of power electronic converters, transient stability should be reexamined in light of their distinctive operating mechanisms. This chapter focuses on the transient stability analysis of grid-following (GFL) and grid-forming (GFM) converters. In particular, the dynamic behavior of the phase-locked loop (PLL) in GFL converters and the influence of virtual inertia and damping in the swing equation of GFM converters will be systematically discussed. In addition, analytical approaches such as the Equal Area Criterion (EAC) and phase portrait analysis will be introduced for assessing transient stability of the converter-based power systems.