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

Protection and Control of Modern Power Systems

Table 7 The line stability indices for the IEEE 118-bus system under heavy reactive power load

Bus no.	Reactive power (MVAr)	Most critical lines	Lines (from–to)	NCPI	L_mn	FVSI	LQP	NLSI	VSLI
Bus-117	152	117–12	117–12	0.9995	0.9778	0.9952	0.8987	0.8932	0.9010
Bus-20	230	20–19	20–19	1.0102	0.9898	1.0102	0.9682	0.9765	0.9846
			20–21	0.5412	0.5379	0.5349	0.5036	0.5439	0.5418
Bus-38	1020	38–65	38–65	1.0030	1.0413	0.9287	0.8074	0.9667	0.9775
			38–30	0.9787	0.9776	0.9558	0.9621	0.9558	0.9616
			38–37	0.9407	0.9275	0.9085	0.8764	0.9005	0.9375
Bus-51	329.5	51–49	51–49	1.0103	1.0015	1.0013	0.8245	1.0001	0.9980
			51–58	0.8185	0.7711	0.8180	0.7262	0.7117	0.7326
			51–52	0.4541	0.4215	0.4440	0.3904	0.3348	0.3584
Bus-33	300	33–37	33–37	1.0046	0.9656	1.0023	0.9068	0.9122	0.8992
			33–15	1.0017	0.9553	1.0010	0.8036	0.8815	0.9023
Bus-96	685	96–80	96–80`	0.9998	0.9737	0.9855	0.9360	0.9696	0.9648
			96–94	0.7963	0.7714	0.7953	0.7213	0.7444	0.7488
			96–97	0.7596	0.7480	0.7562	0.7261	0.7381	0.7378
			96–82	0.7588	0.7351	0.7584	0.6912	0.7046	0.7088