4 Limb Wye-Wye Transformer
4 Limb Wye-Wye Transformer
(OP)
We were in need for a zero phase shift transformer with the characteristics of a delta-wye transformer, and after some research we decided that a 3 winding wye-wye with buried delta could provide this (Yyn0d1).
A well known manufacturer, has now provided us with a 4 limb wye-wye (Yyn0)transformer with the HV ungrounded as an equivalent alternative.
I have tried to research this but cannot find anything with enough detail to indicate that a 4 limb wye-wye is equivalent to a 3 winding wye-wye-delta.
Some texts state that wye-wye transformers should have the HV grounded to allow fault currents to flow for a phase to earth fault on the secondary. However if the HV is ungrounded and is a 4 or 5 limb designs would this be different? Some texts such as 'J&P Transformer Book' appear to imply that for a secondary phase-to earth fault fault current can flow.
Does anyone have knowledge/experience or know where I can find more information on this subject?
A well known manufacturer, has now provided us with a 4 limb wye-wye (Yyn0)transformer with the HV ungrounded as an equivalent alternative.
I have tried to research this but cannot find anything with enough detail to indicate that a 4 limb wye-wye is equivalent to a 3 winding wye-wye-delta.
Some texts state that wye-wye transformers should have the HV grounded to allow fault currents to flow for a phase to earth fault on the secondary. However if the HV is ungrounded and is a 4 or 5 limb designs would this be different? Some texts such as 'J&P Transformer Book' appear to imply that for a secondary phase-to earth fault fault current can flow.
Does anyone have knowledge/experience or know where I can find more information on this subject?






RE: 4 Limb Wye-Wye Transformer
RE: 4 Limb Wye-Wye Transformer
RE: 4 Limb Wye-Wye Transformer
This is a 3 phase 1MVA transformer.
RE: 4 Limb Wye-Wye Transformer
But, why don't you use a delta-wye (Dy0)?
RE: 4 Limb Wye-Wye Transformer
RE: 4 Limb Wye-Wye Transformer
The wye-wye with an embedded delta is also not equivalent to a wye-delta transformer. This is not a ground source unless the primary system is grounded.
RE: 4 Limb Wye-Wye Transformer
RE: 4 Limb Wye-Wye Transformer