TRANSFORMER CONNECTION

[srmoran]

What is the advantage the of the delta-wye connection of distribution tracsformer over wye-wye?

 

[Physis 2]

Re: TRANSFORMER CONNECTION

Less transmission conductors?

 

[steve66]

Re: TRANSFORMER CONNECTION

And non-linear loads on the secondary create harmonics. These harmonics cancel each other in a delta primary. Not so with a wye-wye.

Steve

 

[templdl]

Re: TRANSFORMER CONNECTION

Also, as I understand the constuction of the core of a Y-Y transformer is different requiring a 4 or 5 legged core instead of the common 3 legged core and in the D-Y.

 

[jtester]

Re: TRANSFORMER CONNECTION

Changing the primary connection creates differences in how the transformer bank acts with the primary system. That is one fundamental purpose of different primary connections. In addition to the differences mentioned above, a delta wye increases ground fault currents where a wye wye brings the high zero sequence impedances with it into the low side fault current calculations thereby lowering ground fault current values.

There are many other differences including availability of high side fusing at higher voltage ratings etc. But the basic rule of thumb is that low side connection changes provide different system voltages on the low side, and different high side connections change how the secondary loads and the transformers themselves act in conjunction with the high side system.

Jim T