Grid Stability Analysis with High Renewable Energy Penetration

Abstract

The rapid replacement of synchronous generation by inverter-based wind and photovoltaic resources changes the dynamic behaviour of modern electric power systems. This paper develops a reproducible scenario-based framework for evaluating frequency, voltage and small-signal stability as variable renewable energy (VRE) penetration increases from 10% to 80%. The framework combines an aggregated swing-equation frequency model, renewable variability representation, voltage-sensitivity screening and eigenvalue-oriented damping assessment. A normalized reference system is subjected to a credible generation-loss disturbance and evaluated using equivalent inertia, rate of change of frequency (RoCoF), frequency nadir, settling behaviour, voltage deviation and damping ratio. The illustrative numerical study shows a systematic deterioration of stability margins as synchronous inertia is displaced: equivalent inertia falls from 5.8 s to 2.3 s, peak RoCoF rises from 0.18 to 1.08 Hz/s, and the post-disturbance frequency nadir declines from 49.72 to 48.73 Hz. The study then evaluates grid-forming inverter control, battery energy storage with virtual inertia, fast frequency response and coordinated reactive-power support. Coordinated mitigation provides the strongest overall response in the illustrative 80% VRE case, reducing peak RoCoF to 0.39 Hz/s while improving voltage and damping performance. The results support a transition from penetration-only planning criteria toward stability-constrained, data-informed operating envelopes. The proposed structure is aligned with computer information systems and industrial-management applications through its emphasis on measurement, analytics, control coordination and operational decision support.