Thermal Module - Winding Losses

I determine losses of cores and windings with the thermal module. I would like to know how PSIM determines winding losses, as I get different results with my calculations.

I also noticed that winding losses increase by using larger conductors. However, this does not make sense since the resistivity (Ohm/m) decreases with size.

For example, if I use the example project Buck - inductor losses and change the wire size (e.g. from AWG18 to 17 or 10) and nothing else, I get higher winding losses.

I need the thermal module for a paper. It would be great if you could help me with some information.

when you change wire size you are also changing the geometry of the winding. If you do not change the number of turns you are increasing the volume of copper used which would then force the windings closer to the core which would increase your proximity losses. Proximity losses are one of the main loss mechanisms in indcutors.

#Thank you Sir!

I did not though that PSIM takes proximity losses into account, now the results match with my calculations.

Many thanks!