No phase shift between systems

[Mbrooke]

Basically I have come up with an idea to eliminate 30 and 60 degree phase shifts between transmission and distribution. The plan is to step down 132kv to 33kv via a Wye grounded delta transformer (YNd11) which produces a 30 degree shift and have a 33kv to 12kv delta wye (Dyn01) with an apposing 30 degree phase shift relative to the 132/33 transformer. The end result would be having the 12 kv distribution system in phase with the 132kv system.

Playing with a Fermat point I think this is doable?


Is this approach practical?

 

[Mbrooke]

Is there an option for a free view, its asking me to sign in as a member or purchase it?

 

[bwen08]

The Basler paper on three winding transformer differential relaying is a good resource on connections and shifts. See the FAQ on Can I parallel a DY1 and DY11 transformers and the Basler paper is linked in it:

http://www.eng-tips.com/faqs.cfm?fid=1154

Sorry the its an jpg, all I had to get it online, but this is what your after.

 

[Mbrooke]

Thank you!

Yes that is it, having transmission and distribution be at 0 degrees in regard to one another. I really appreciate the your effort, and trust me, the upload is legible.

I will read through the paper to get an idea of what connections are parellable.


One more question that's slightly off and on topic. In cases like this Ive been told that in theory the best solution is delta detla at the transmission and delta delta at the distribution. Deriving a ground point aside (Ive done it many times) is there anything that would stop me such as tap changers from having a delta delta 132 to 12kv or 132 to 33kv transformer? Id imagine tap changes perform differently on a delta secondary as apposed to a wye?