Critical Comparative Analysis of Measurement based Centralized Online Voltage Stability Indices

In this paper, a detailed comparative analysis of measurement based centralized voltage stability monitoring approaches using Thevenin equivalent is presented. These methods typically utilize the state estimation output, making them easily implementable at the control centers. The metrics for comparison are defined in terms of computation resources required, accuracy of identifying the critical loading point, critical contingency screening, and robustness to noise. These performance metrics are relevant for practical implementation and are presented on the IEEE 300 bus system and the MATPOWER 2383-bus system. To the best of our knowledge, this is the first systematic qualitative & quantitative comparison between various measurement based voltage stability methods using these performance metrics. The results will guide the utilities and operators about possible trade-offs between the various methods for large systems, enabling them to make an informed decision on the specific method to use for their needs.