A novel collapse prediction index for voltage stability analysis and contingency ranking in power systems

Protection and Control of Modern Power Systems

Table 8 The line stability indices for the IEEE 118-bus system under heavy apparent power load

Bus no.	Apparent power P (MW), Q (MVAr)	Most critical lines	Lines (from–to)	NCPI	L_mn	FVSI	LQP	NLSI	VSLI
Bus-117	P = 137 Q = 106.2	117–12	117–12	0.9817	0.9405	0.7088	0.3653	0.8758	0.9792
Bus-20	P = 180 Q = 165	20–19	20–19	0.9789	0.8961	0.7869	0.5942	0.8934	0.9005
Bus-20	P = 180 Q = 165		20–21	0.3478	0.2937	0.2721	0.1847	0.3734	0.3857
Bus-30	P = 920 Q = 710	30–26	30–26	0.9834	0.7737	0.5941	0.2027	0.6971	0.8922
			30–8	0.8230	0.8191	0.8067	0.7812	0.8225	0.8042
			30–38	0.8988	0.8868	0.6292	0.8722	0.4665	0.3874
			30–17	0.5861	0.5844	0.5839	0.5818	0.5839	0.6663
Bus-50	P = 300 Q = 278	50–49	50–49	0.9920	0.9556	0.7231	0.3302	0.9220	0.9906
Bus-50	P = 300 Q = 278		57–50	0.8579	0.8419	0.7866	0.6057	0.8670	0.8691
Bus-96	P = 570 Q = 490	96–80	96–80	0.9562	0.8734	0.6384	0.2567	0.8097	0.9958
			96–94	0.7479	0.7312	0.6866	0.5546	0.7664	0.7809
			96–97	0.6940	0.6077	0.5230	0.3136	0.6595	0.7790
			96–82	0.6460	0.5950	0.5230	0.3474	0.6744	0.7325