Online Estimation of Power System Inertia Using Real-Time WAMS Data in Vietnam

The increasing penetration of converter-interfaced generation has significantly reduced power system inertia, posing new challenges for frequency stability assessment. This paper presents an online inertia estimation method based on real-time wide-area measurement system (WAMS) data. By exploiting synchronized measurements of active power imbalance and frequency response, the proposed method estimates inertia without requiring detailed system models and can be directly integrated into existing WAMS & SCADA/EMS infrastructures. The approach is validated using actual WAMS data from the Vietnamese power system at both power plant and regional levels. The estimated inertia is further confirmed through comparison with inertia values derived from SCADA-based calculations. The results demonstrate the practicality of the proposed approach for real-time inertia monitoring in modern power systems.