Ranking power system contingencies for real-time assessment of voltage stability based on PMU data

Voltage stability has been one of the main challenges for power system operators in recent years. Theranking of contingencies is one of the practical factors in assessing voltage stability. Therefore, the importanceof maintaining grid stability necessitates the real-time assessment of voltage stability to protectthe system from the risk of instability, and contingency ranking provides a list of essential and criticalcontingencies in terms of their impact on the network for real-time use. In this paper, a new index for classifyingcontingencies is presented, which is defined based on the voltage deviation and phase angle of thebuses and PMU data. The proposed index has been tested on the IEEE 30-bus network. First, using thisindex, a contingency study was performed in 1000 operating points, and in the second stage, the resultsof these studies were compared with a random operation point. Comparing the results obtained fromthe proposed index with other available indices shows its proper performance for ranking and screeningpossible contingencies in power systems.