Mechanism investigation of inertia variation impact on power system small signal stability

The inertia of power system is a key parameter that has a huge impact on the system small signal stability. With increasing penetration of renewable energy, the effective inertia is reduced which would bring small signal stability issues to the power system. Thus, it is an urgent need to find out the mechanism how inertia influences the small signal stability. In this paper, the impact of inertia variation on the system small signal stability is investigated. The influence of inertia on eigenvalues of oscillation modes is mathematically modelled by using damping torque analysis (DTA) in a multimachine system. Finally, the eigenvalues loci demonstrate the effect of inertia change on oscillation modes in a single machine infinite bus (SMIB) system and four-machine two-area (4M2A) system.