If we choose the transformer y n d11, then what is the advantage of secondary side phase shift?

Question

If we choose the transformer y n d11, then what is the advantage of secondary side phase shift?

Answer 1

I'm not quite sure what "y n d11" means, but a 3-phase transformer with a delta primary only needs a three legged core.  A wye primary will require a five legged core.  More core steel = more expensive transformer.

The delta primary winding also helps prevent harmonics from traveling back on to the primary system.

Unless you are trying to parallel the secondaries of wye and delta transformations, there is really no reason to worry about the phase shift.

Answer 2

Dear pa,

Thank you, am also fine like you then dear  am also one electrical engineer but i cann`t understand your question.If possible send email am ready to try for you.

Answer 3

For most installations, there is no particular benefit to choosing one phase shift over another.  E.g. Ynd11 is comparable to Ynd1 or Ynd5.

However, there are 2 conditions where choice of vector group phase shift is very important.

1.  If the secondaries circuits of two transformers will be connected in parallel, they must have the same vector group, same phase rotation, and the same phase angle.  Otherwise, currents will circulate between the transformers.  These current can be very high due to the relatively low impedances of the transformers.

2. If the transformer is part of a harmonic current cancellation scheme, such as in a 12-pulse rectifier, the choice of phase shift matters, because the engineer is using the phase shift of the transformers to achieve net 180° phase angles between certain harmonic currents to have them cancel each other.