Fault current through different transformers
Fault current through different transformers
(OP)
Hi guys,
Hope somebody will be able to help me to understand something I'm struggling at the moment :)
I'm trying to understand how fault refers thorough different transformer vector group.
The one we have is Dzn0 but I want to fully understand how for example phase to phase fault on the lower side will refer to the higher. Our transformer is 33/11kV but again that's not important as I get really interested in fully understand how that works, but unfortunately never dealt with the protection of the transformer itself.
Anyway I have spent lots of time on internet and my old book and notes.
I know what turn ratio I have got and what a different transformers have (Dy= √3N, Yz=3N etc).
The problem I have I unfortunately can't find it anywhere! Is how will phase to phase (or phase to earth) refer through transformer. I have found that for the Dy it is 2:1:1.
However can't find anything for different groups and what important I cannot find explanation how to get to the answer. I would like to get my head around and understand how to get that current distribution for different transformers so I don't have to struggle every time we have to supply different transformer.
I would be grateful for any advice.
Hope somebody will be able to help me to understand something I'm struggling at the moment :)
I'm trying to understand how fault refers thorough different transformer vector group.
The one we have is Dzn0 but I want to fully understand how for example phase to phase fault on the lower side will refer to the higher. Our transformer is 33/11kV but again that's not important as I get really interested in fully understand how that works, but unfortunately never dealt with the protection of the transformer itself.
Anyway I have spent lots of time on internet and my old book and notes.
I know what turn ratio I have got and what a different transformers have (Dy= √3N, Yz=3N etc).
The problem I have I unfortunately can't find it anywhere! Is how will phase to phase (or phase to earth) refer through transformer. I have found that for the Dy it is 2:1:1.
However can't find anything for different groups and what important I cannot find explanation how to get to the answer. I would like to get my head around and understand how to get that current distribution for different transformers so I don't have to struggle every time we have to supply different transformer.
I would be grateful for any advice.






RE: Fault current through different transformers
RE: Fault current through different transformers
RE: Fault current through different transformers
Typically they are used as an earthing transformer for 3-wire systems with no neutral.
They also sometimes turn up in power electronic systems such as UPS output stages where they can aid in suppression of triplen harmonics.
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RE: Fault current through different transformers
I have seen YNzn11( Mumbai,India)and YNzN5( Surinam) connection in some parts of the world.Then I understood that it is to avoid stabilising tertiary winding eventhough Z winding will have 15 % more copper than equivalent voltage Y winding.