Transformer Vector group

[alansam]

1.I think Dyn11 vector group is the most commonly used vector group in distribution transformers.This means the low voltage supply lags behind high voltage by 30 degrees.As per my understanding this is merely done to compensate for the Phase lead provided at the generation side by Yd1 step up transformer.

So y do we use Yd1 transfromer at the generator side at all?Cant we use Yy or Dd transformer at the gen side so that we can use a similar kind in the distribution side too??I mean the requirement is to just step up the voltage so that it can be transmitted over long distances.Why introduce a phase diff at the gen side?

I know this might include a lot of explanation and maths..I would be glad if any1 could give me an explanaion and a link for the math(i mean network analysis)

Regards,

Alan

 

[Knobhead]

With a generator transformer the phase shift doesn’t matter, the unit is synchronised to suit the network. ∆yn11 is as you say is the standard. A Yy is very poor at filtering out system harmonic, Y autotransformers have a very low reactance, therefore a have a high fault let through.
Have sent you a PM.

PS. don’t start multiple threads, it annoys people and information get dis-jointed.