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

Protection and Control of Modern Power Systems

Table 11 Contingency ranking and analysis of the IEEE 30-bus system with pre-specified reactive power load at (a) buses 4, 7, 9, 16 and 20, (b) nodes 4 and 16, (c) nodes 7 and 28

Generator outage	Rank	Most stressed lines	NCPI	L_mn	FVSI	LQP	NLSI	VSLI
(a) Prespecified reactive power load: Q4 = 205 MVAr, Q7 = 187.5 MVAr, Q9 = 145.8 MVAr, Q16 = 65.5 MVAr, Q20 = 50.5 MVAr
Gen. 5	1 (Critical)	8–6	0.9441	0.9429	0.9022	0.8376	0.8108	0.7862
	2 (Critical)	9–11	0.9003	0.9003	0.9003	0.9003	0.9003	0.9003
	3 (Stressed)	16–12	0.8569	0.7988	0.8530	0.6849	0.7445	0.7575
	4	7–6	0.7544	0.7374	0.7468	0.6625	0.7267	0.7260
	5	20–10	0.7438	0.7101	0.7371	0.6030	0.6751	0.6799
	6	4–2	0.6352	0.6172	0.5829	0.4709	0.6617	0.6684
(b) Prespecified reactive power load: Q4 = 205MVAr, Q16 = 65.5MVAr
Gen. 13	1 (Most stressed)	4–12	0.8565	0.7663	0.7511	0.8565	0.7511	0.2716
	2	16–17	0.5193	0.4947	0.5191	0.4386	0.4273	0.4387
	3	4–2	0.4616	0.4478	0.4292	0.3564	0.4941	0.4948
	4	16–12	0.4511	0.4374	0.4491	0.3641	0.4006	0.4033
(c) Prespecified reactive power load: Q7 = 187.5 MVAr, Q28 = 181.5 MVAr
Gen. 8	1 (Critical)	7–5	0.9497	0.8733	0.9492	0.8180	0.8049	0.8355
	2	10–6	0.7839	0.6804	0.6666	0.7839	0.6666	0.7038
	3	28–6	0.7142	0.6988	0.7131	0.6575	0.6777	0.6719
	4	28–8	0.5989	0.5816	0.5989	0.5436	0.5438	0.5389