there seems to be some issue regarding modelling of the no load losses of power transformers (standard model, 3 phase 3 winding transformer). PSCAD doesn't seem to accept values less than 0.001 pu (referred to transformer rating). Values greater than 0.001 pu aren't realistic for large power transformers. Example: Transformer rating: 300 MVA No load losses (measured): 100 kW No load losses [pu]: 0,00033 [pu]. PSCAD calculations return more or less constant value of P up to no load losses of 1e-3 [pu].
Maybe I should formulate the question the other way round: What should be entered as transformer parameters in PSCAD, given that the following values obtained from measurements are available?
Winding voltages: 400/120/30 kV Rating: 300/300/60 MVA No load losses (measured at tertiary winding): 80 kW Short circuit test: Pk1-2 = 600 kW, Pk1-3 = 100 kW, Pk2-3 = 100 kW. Magnetising current: 0,04% (referred to primary side MVA). The same question applies to core saturation curve, which is normally measured at the tertiary winding.