Search

The nonuniform large damping introduced by grid-forming (GFM) converters in multi-machine system could destabilize the power system under large disturbance, which may bring new challenges to the safe operation of future power system. In this letter, the mathematic model of GFM-penetrated multi-machine system considering large damping effect is established first, and the concept of uniform and nonuniform damping energy is further proposed to clarify the impact of different damping components. Moreover, the influence mechanism of nonuniform damping on system transient stability is revealed, which implies that the large damping in only part of generators could destabilize the system. The analysis result may provide some new insights for the transient stability analysis of future power system with nonuniform damping effect.