Estimate transformer loss from nameplate impedance?
Estimate transformer loss from nameplate impedance?
(OP)
Is it possible for me to make a rough estimate of the loss that a three-phase 360 kVA power transformer would have just from the percent impedance listed on the nameplate? Any insight appreciated! Thanks, Fred






RE: Estimate transformer loss from nameplate impedance?
Transformers are very efficient. If you assumed 2% loss at full load, that would probably be conservative, unless there is something special about this transformer.
RE: Estimate transformer loss from nameplate impedance?
R% = Z%·cos(atan(X/R))
FL loss = rating·R%
RE: Estimate transformer loss from nameplate impedance?
RE: Estimate transformer loss from nameplate impedance?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Estimate transformer loss from nameplate impedance?
You need the load loss and the impedance to calculate regulation - See IEEE C57.12.90 Section 14, Calculated Data.
RE: Estimate transformer loss from nameplate impedance?
It sounds that from the consensus, although this transformer has a Percentage Impedance of almost 7%, I can expect an efficiency of better than 96%.
I really appreciate the feedback. Fred
RE: Estimate transformer loss from nameplate impedance?
I would expect the efficiency to be higher than 96%.
Also, the efficiency varies with the load on the transformer.
RE: Estimate transformer loss from nameplate impedance?
Replace the word impedance with the word efficiency.
The regulation or PU voltage drop (or rise, to carry the accuracy to the 4th or 5th significant figure) will approximate the load losses.
The PU current deficiency at no load will approximate the no load losses.
A catalog or brochure may list the regulation and/or the efficiency. The test report confirms that the transformer meets the published figures.
No. The regulation figure will give a much closer rough estimate than the impedance, but still ignores lo load losses.
Bill
--------------------
"Why not the best?"
Jimmy Carter