open delta connection

[saltukhan]

why open delta connection causes 30 degree phase shift? can you explain this ? also is 30 degree phase shift obligatory or design issue in delta-wye connections?

 

[ramsirv]

I found some basic information on a diff thread, the link to which I have attached here-in. I am not sure if that will answer your question, but i guess its never the less worth a click.

http://www.powerlineman.com/lforum/showthread.php?t=1931

I think there are a couple of vector diagrams in there that may help clarifying the concept.

Cheers
Ramsi

 

[saltukhan]

yes i think a vector diagramme would be nice... thank u nevertheless...

 

[waross]

There are a few misconceptions in the information in the other forum.
There is a 30 degree phase shift inherent from the primary to the secondary of a wye/delta or delta/wye transformer or bank. It doesn't matter if the delta is open or closed.
It has to do with the phase angle between the line to line voltage and the line to neutral voltage in a wye system.
In a wye transformer, there is a 30 degree shift between the line to line voltage and the line to neutral voltage. The delta voltages are in phase with the line to neutral voltages.

An open delta has a similar phase angle between the primary and secondary.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ramsirv]

Bill,

Thanks for the clarification. I apologize for pointing to the other thread without reading through the same.

Ramsi

 

[driesterer]

Hi saltukhan,
Did you ever find that vector diagram? I am looking for the same information.

 

[waross]

Open delta? draw a closed delta and remove one transformer.
Note: If the primary is we connected, the neutral point should be floating in a wye/closed delta connection.When one transformer is removed, the wye point of the remaining two transformers must be connected to the primary neural.
Vector diagram? Draw a closed delta vector diagram and remove one vector.

Bill
--------------------
"Why not the best?"
Jimmy Carter