Transformer Vector Group 1

[markjp]

Have a question regarding transformer vector group selection. There are some very helpful threads on the pros and cons of delta and wye connections, however I was wondering if the vector group of a transformer located higher (upstream) in a power system has any influence for any reason over the selection of the vector group for a transformer downstream. In particular our project has a main 33/11kV Dyn11 transformer installed and now requires an 11kV/690V transformer to be installed below it, preference is for Dyn11 also. Appreciate if any feedback can be provided as to whether any special considerations may be required on this. Many thanks.

 

[davidbeach]

At least in the ANSI world, standard configuration is that the high side leads the low side by 30[°], no puzzling over vector groups. But in what ever case, if there are other sources of 690V that could be paralleled with your new 690V, you want the same vector group as the existing.

 

[Kiribanda]

markjp,

Yes, as pointed out by davidbeach, someday if you are going to put a transformer directly from 33 kV/ 690 V and intending to do any paralleling at 690 V bus, then there will be a problem.

 

[markjp]

Thanks for your help guys.