Transformer load-rate / loss curve — quick reference
Enter the transformer nameplate loss data and the engine sweeps the load rate from no load to full load, returning the iron loss, the copper loss and the total loss at every point. The curve and the composition are drawn from the engine array; quantities the engine does not output are shown as not available - never as zero.
Sample case pre-filled: 1000 kVA transformer, P0 = 1700 W, Pk = 14500 W, 40 °C ambient. Overwrite the fields with your own values - every number below is computed by the engine.
RequiredRecommendedLeft bar: blue = required, gold = recommended. Optional and advanced fields are collapsed by default.
Not calculated yet - fill in the input data and press the button.
Loss model: P_loss = P0 + Pk x (S/Sn)^2 (iron loss constant, copper loss proportional to the square of the load rate). P0 / Pk are taken from the values you enter; if you leave them blank the engine substitutes GB 20052-2020 grade-1 typical values and the substitution is disclosed in the engine text.
The load-rate sweep is produced by the platform engine engines/params.js lossAt() over the engine parameter set engines/trafo-ageing.js tempRiseSweep (21 points, 0-100 %). The page renders the returned array and adds no curve of its own.
Transformer efficiency eta = P_out / (P_out + P_loss) is not output by the engine; per the platform rule (no second implementation) it is shown as not available. The engine load-zone judgement is available from the engine text.
Sample case: the pre-filled 1000 kVA transformer gives the sweep shown; overwrite any field and press Calculate again. Missing values are shown as not available, never as zero.
The sweep is the engine single-loss-model evaluation at different load rates (P_loss = P0 + Pk x (S/Sn)^2, ONAN temperature-rise model in IEC 60076-7). Transformer efficiency eta is not output by the engine and is therefore shown as not available - this page does not compute a second implementation.