Transformer Protection

Sounds like you are in need of an engineer to help you. This is too complex for you to try this with information from a web site.

I know very-well about protection of HT system , but in this case my requirement is in LT system, so i am confused. If this is related to HT system then i will put o/c protection in primary side and secondary side and provide differential protection for transformer( WTI,OTI,Buc. relay trip protection too). in this case i have a facility of outdoor switchyard and i am very easily provide this protection. Now my system is LT (11/22Kv) I/C and O/G by cable, so i need to provide all above protection to TR?. Is there above maintain transformer have a WTI, OTI and Buch. Relay?

OP,

I agree to wareagle. The answer to this question is not so trivial and can not be asked by a person who will be doing the design of the protection of such a (11/22KV, 20MVA) transformer. Anyway, you can search for "Transformer Protection" from the previous threads. I at least know one that may help:

http://cr4.globalspec.com/thread/37625

-MS

grate ans by all user. But anyway i was found a IEEE standard for minimum KVA/MVA requirement of differential protection. all other protection is as per standard practices. if u have any difficulty regarding your system design then "I am available to you ".