Transformer Data
* Required fields. Optional fields will use estimated defaults if left blank.
Results
Total Losses
Breakdown
Transformer losses are one input to a load flow. A load flow study takes every transformer and cable in the network together. Load flow and power system studies →
Enter a valid email address.
Opens the print dialogue. Choose “Save as PDF” to keep a copy.
Transformer Loss Equations (Schneider Electric)
Active Losses:
P = LWCu + LWFe
LWCu = Pk × (I/In)²
LWFe = P0 × (V/Vn)²
Reactive Losses:
Q = LVCu + LVFe
LVCu = √(S×Z%)² - Pk² × (I/In)²
LVFe = √(S×I0%)² - P0² × (V/Vn)²
Frequently Asked Questions
How are transformer copper losses calculated?
They scale with the square of the load: LWCu = Pk x (I/In)^2, where Pk is the load loss at rated current. At half load the copper loss is a quarter of Pk.
How are iron losses calculated?
LWFe = P0 x (V/Vn)^2, where P0 is the no-load loss. They depend on voltage, not load, so they are present whenever the transformer is energised.
How are the reactive losses worked out?
LVCu = root((S x Z%)^2 - Pk^2) x (I/In)^2 for the leakage reactance, and LVFe = root((S x I0%)^2 - P0^2) x (V/Vn)^2 for magnetising. The tool takes the no-load current I0 as 1 % of rated current.
What if I do not know the impedance or load losses?
Leave them blank and the tool estimates them from typical values by rating, and lists the estimates under the results. Use the test report values for anything you rely on.