# Phase Shifts in Transformers:



## Redskinsdb21 (Apr 6, 2012)

When you have a transformer, delta-wye, delta-delta, ye delta, wye-wye....

What is the phase shift of secondary voltages and currents after converted to secondary voltage and current values based on turns ratio? Cant seem to find any infp. on this?


----------



## Wildsoldier PE (Apr 6, 2012)

I think chapman book explains this...the advantages and disadvantages of each configuration...but im not sure if it was chapman or wildi book


----------



## vskneifl (Apr 6, 2012)

Typically the only time their is a phase shift is when you go from a delta to a wye or wye to delta and it is a 30 degree phase shift, a delta-delta and wye-wye will not have a phase shift. It is standard to always have the secondary side lag the primary side but a transformer can be designed to be lagging or leading, for that matter a transformer can be designed to have any phase angle required. Hope that helps.


----------



## Flyer_PE (Apr 6, 2012)

In addition to the transformer design, the connections to the system can be manipulated to give you a 30 degree phase shift in either direction.


----------



## DK PE (Apr 7, 2012)

vskneifl said:


> It is standard to always have the secondary side lag the primary side...


I thought the ANSI standard that is commonly applied in the US specifies the positive sequence voltage on the low voltage side lags the high voltage side. If you have a step down transformer, your terminology is correct, if it is a step up transformer, you would be incorrect.


----------



## robertplant22 (Apr 7, 2012)

I'm going to agree with DK PE on this one. My understanding is that the HIGH side will always lead the LOW side by 30 degree regardless of transformer configuration (delta - Y, or Y - delta).

I'm sure this phase shift can be modified for particular applications, but unless otherwise stated in a problem, what DK PE states above is correct.


----------

