Investigating the Effectiveness of a Voltage Stability Index for Analyzing the Impact of Contingencies Scenarios on an Electricity Transmission Network

Abstract

Given the potential for a range of malfunctions or contingency scenarios in an electrical system, it is crucial to assess their implications in advance to predict the stability of the electrical system. Techniques based on stability indices have been proposed in the literature to assess the impact of a contingency, yet their effectiveness remains limited. In this paper, the Complex Stability Index for Transmission Line (CSITL) is employed to evaluate the consequences of $\mathrm{N}-1$ contingency scenarios in an electric power transmission system and to categorize these scenarios according to the severity of their impact on system stability. The study is validated using the standard IEEE 30-bus network under base load conditions. The performance of CSITL is then compared with that of the Power Performance Index (PPI), the Voltage Performance Index (VPI), and the Novel Collapse Prediction Index (NCPI). The results demonstrate that for the line 1-2 interruption scenario, the PPI and VPI exhibited vuInerability indices of 23.7 and 0.09, respectively, whereas the CSITL and NCPI demonstrated average gaps in relation to the value at the stability limit of $\mathbf{- 1. 3 9}$ and -2.38, respectively. This contingency has the most serious impact according to the Power Performance Index (PPI), the Complex Stability Index for Transmission Line (CSITL), and the Novel Collapse Prediction Index (NPCI). The six contingencies identified as the most severe by the PPI were also identified as the most severe by the CSITL and the NCPI. However, for each of these contingencies, the CSITL identified at least six critical or stressed lines, while the NCPI identified only one stressed line for the sixth contingency.