Is there a good tutorial on transformer vector group change using cable phase swap and rollover? 3

[electrical429]

I understand transformer vector groups, however I get confused when it comes to changing phase order outside the transformer to change it's vector group. For example the following statement:

"For this connection the outer HV phase conductors are effectively swapped, with phase Red connected to transformer terminal C and phase Blue connected to transformer terminal A. This needs to be repeated on the LV side of the transformer to obtain a conventional vector group. Swapping the conductors in this way reverses the effect of the transformer, achieving an effective Yd1 vector group from a Yd11 transformer. This is called a negative sequence connection."

or

"Similarly a Yd8 can be achieved from a Yy0 by rolling the conductors from R -> Y -> B."

 

[beyond86]

See this link

https://electrical-engineering-portal.com/understanding-vector-group-transformer-1

 

[stevenal]

[URL unfurl="true"]https://www.eng-tips.com/faqs.cfm?fid=1154[/url]

 

[cuky2000]

See if this Link and image below can help.

 

[mvcjr]

Good day!

My humble tip...

Swapping two corresponding leads in the primary and secondary of a transformer will effectively change the functional vector group of the transformer. The nameplate vector group still remains the same.

To determine what is the vector group change, use the following:

New functional vector group = 12 - clock number of original vector group

Examples:
1. A Dy11 transformer will become a functional Dy1 transformer (12-11 = 1).
2. A Dy5 transformer will become a functional Dy7 transformer (12-5 = 7).

Hope this helps.

Regards.

 

[mvcjr]

"Similarly a Yd8 can be achieved from a Yy0 by rolling the conductors from R -> Y -> B."

Further, a Yd8 can not be formed from a Yy0 transformer. You can not alter the winding configuration no matter how you swap the transformer leads. A Yy transformer will always be Yy. A Dy will always be Dy.