a. A 3 phase overhead transmission line has equivalent spacing of 5.5m between 8
conductors and conductor diameter is 3 cm. Atmospheric temperature 15109 0806
barometric pressure is 740 mm of Hg. Surface irregularity factor for stranded conductors
is 0.9. Calculate the followmg.
i) Critical surface stress peak value, for fair weather and visual corona, for
both centre conductor and side conductor. ii) Critical disruptive phase
voltage and phase to phase voltage for visual corona under fair weather
condition

b. Discuss the affecting corona losses in EHV system 4

a. Explain the significance of creepage distance for AC insulators and DC insulators 6 in insulation
coordination.

b. Explain the biological effects of EHV lines 6
a. Explain the surge arrestor protection for a typical HVDC converter station. 6

b. Discuss the importance of insulation co-ordination in power systems 6