Tap changing in 765 KV Power Transformers

[prc]

Do tap changing is required in Power Transformers (generator and auto ) used in 765 Kv transmission system?If so what is the normal range of tap changing used?Is it OLTC or DETC? In such trfs tap changer will be a weak link in trfs and hence can we avoid tap changers in UHV system and get system voltage stability using tap changing in EHv system? What is the practice in countries where UHV is used,say US,Canada,Russia ,Brazil(?)

 

[jbartos]

Suggestion: Visit

http://www.condumex.com.mx/cdxinc/powertst/trans.pdf

for a tap changer at 230kV

http://www.imp-power.com/pr_oltc.html

for a tap changer at 66kV

http://www.selinc.com/techpprs/6136.pdf

etc. for more info