“…Whereas, system variable based indices such as L index, stability index (SI) [16], voltage collapse index (VCI) [17], Lmn index [18], LQP index [19], fast voltage stability index (FVSI) [20], voltage collapse point indicators (VCPI) [21], P-index [22], use the admittance matrix elements, bus voltages or power flow details. Voltage stability margin can be calculated in less time and these indices are more suitable for online monitoring applications [23]. Review and comparison of various VSIs proposed by the researchers [24], [25] in the last thee decades clearly shows the scope for investigation for the present study.…”