Wye transformer phase shift
Wye transformer phase shift
(OP)
I am reading different specifications for the same 345 MVA, 20kV-145kV, delta(20kV), wye (145kV) step up transformer. One is from a recent purchase, the other is for a purchase we are to make within the next few weeks.
I notice that one calls for the lower voltage vector to lag the high voltage vector by a phase angle of 30 degrees. The other calls for the high voltage vector to lag the low voltage by 30 degrees - exactly opposite.
Do these specs match?
I notice that one calls for the lower voltage vector to lag the high voltage vector by a phase angle of 30 degrees. The other calls for the high voltage vector to lag the low voltage by 30 degrees - exactly opposite.
Do these specs match?






RE: Wye transformer phase shift
RE: Wye transformer phase shift
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Wye transformer phase shift
FAQ238-1154: Can I parallel a DY1 and DY11 transformer?
"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg
RE: Wye transformer phase shift
If the leads were swapped on the low voltage side what would that do to the phase angle? A-phase is connected to C, C to A?
RE: Wye transformer phase shift
On the other hand, as dpc's link leads to, you can take a DY transformer, either a DAB or a DAC, and get any odd multiple of 30° as your phase shift. Had a good reason once that I wanted the low side to lag by 90° rather than 30°, so line crew and wiremen went to work swapping things around on both sides and a Dyn1 became a Dyn3. Good thing the core positive and negative sequence impedances are the same since the core went from an H1-H2-H3 rotation to an H1-H3-H2 rotation.
RE: Wye transformer phase shift
I'd forgotten about the FAQ dpc, thanks for the reminder.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Wye transformer phase shift
"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg