Analysis of Electrical Characteristics of Composite Insulators with the Presence of Optimum Layer of ZnO Microvaristors

Table 10

Failure risk () for different modelling of insulator.

Footing impedance (ohm)	Clean insulator		Polluted insulator
	Without microvaristor; CFO =1495.87 (kV)	With microvaristor; CFO =1689.11 (kV)	Without microvaristor; CFO =1225.49 (kV)	With microvaristor; CFO =1413.70 (kV)
	F.R. (%)	F.R (%)	F.R (%)	F.R (%)
20	0.135	0.076	0.242	0.159
100	0.296	0.193	0.436	0.328
200	0.405	0.294	0.481	0.449