  With the increasing integration of inverter-based resources into the power
grid, there has been a notable reduction in system inertia, potentially
compromising frequency stability. To assess the suitability of existing area
inertia estimation techniques for real-world power systems, this paper presents
a rigorous comparative analysis of system identification, measurement
reconstruction, and electromechanical oscillation-based area inertia estimation
methodologies, specifically applied to the large-scale and multi-area WECC
240-bus power system. Comprehensive results show that the system
identification-based approach exhibits superior robustness and accuracy
relative to its counterparts.
