an IEEE or ANSI standard phase shift of 30 degrees 1

[harlivsk]

Can anyone point me

that why is there an IEEE or ANSI standard phase shift of 30 degrees between a transformer primary and secondary

 

[jghrist]

ANSI/IEEE C57.12.00

 

[dpc]

Well there HAS to be a phase shift in a delta wye transformer. The referenced ANSI standard just establishes a standard direction for the phase shift.

 

[Skogsgurra]

There is not always a phase shift between primary and secondary.

But, if there is, it is always n*120 +/-30 degrees, with a possible 180 degrees added. Simply because the voltage vectors are off by +/-30 degrees if the primary is delta connected and the secondary is wye connected.

Having said that, it is time to go back and say that lots of different phase angles can be had. Especially if one of the windings is a Z winding.

But 30 degrees is very common.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[dpc]

Gunnar,

That's news to me. How do you build a standard two-winding delta-wye transformer with no phase shift between the delta and wye windings?

 

[Skogsgurra]

There are Y/Y transformers. You do know that.

Gunnar Englund

http://www.gke.org

--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[waross]

I understood that the primary and secondary windings of a transformer were always in phase.
The transformer phase shift results because the phase voltage from a delta winding is in phase with the winding, and the phase voltage from wye connected windings is the vector sum of the voltages of two windings that have a 120 degree phase displacement.
respectfully

 

[dpc]

Yes, I know about wye-wye transformers I guess I assumed he was talking about delta-wye (as I mentioned in my reply) because of the reference to standard 30 deg phase shift. I probably didn't read your answer closely enough.

waross,

Yes, that's my understanding as well. But unless you're doing something really special, there will be a phase shift between the H and X bushings on a delta-wye or wye-delta unit.

 

[Skogsgurra]

He actually asked why there is a thirty degree phase shift between a transformer primary and secondary. He said nothing about delta or wye and obviously wasn't aware of it either. I thought I should give him the whole story.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[dpc]

He asked why there was an ANSI-standard phase shift. There's no ANSI-standard phase shift on a wye-wye transformer

 

[Skogsgurra]

We could go on forever...

Gunnar Englund

http://www.gke.org

--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[cuky2000]

There is also 30 degrees phase shift with the wye (Y) zigzag (ZZ) transformer as shown in the enclosed table at

http://cuky2000.250free.com/Zigzag_Data.gif

There is available phase shifting transformers design that could vary the phase angle in a wide range the primary with respect to the secondary output.

 

[sslobodan]

There is a phase shift between transformator sides that is equal to a n*30 degrees where n is whole number. n is called hour number and is usually mentioned on the nameplate. This is definition of the hour number for transformers, It goes in all European standards, so I believe it sounds the same from the another side of Atlantic ocean.

 

[pajce]

Agree with Sslobodan.
It's just a matter of how you connect winding taps internally in the transformer. I believe in Europe it is common to have Dy5. Here in North America we usually have Dy1 or Dy11.

 

[ScottyUK]

Dyn11 is a very common final distribution transformer in the UK. dYN1 is a normal generator step up transformer. There are probably 'standard' types out on the transmission system too but that's not my patch.


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