Mathhhew said:
Is there some kind of order of magnitude of current related to the section of the wire it is going through or a way to estimate it if I know from what kind of equipment it comes from? I'm not trying to have a precise value, only an estimation
Yes. You'll first make some assumptions about the design, a preliminary design. Then you'll calculate the worst case, losses. You'll want to divide these into copper losses and core losses. The copper losses are essentially just the resistance of the winding, for which you need the resistance per turn, number of turns, and the mean length per turn. Don't forget to adjust for the elevated temperature of the wire. As I said, core losses don't matter much for DM currents, since the H field cancels. Then your left with a difficult thermal problem for whatever structure you have. Most likely you will use an iterative approach to fix the stuff you don't like in the results with a modified design.
In short, you have to learn how to design magnetics like the EEs that do that for a living. There are some papers out there on the net, but I don't think you'll find much like a tutorial or book. It's just a bit esoteric for that. This is one of many reasons you may be better off buying a CM choke than designing your own.
Back in the day, I learned this from
this book (an earlier version, actually), which has some very practical approximations. Ultimately, good designs end up being measured anyway. It's often easier and more accurate, since there are a lot of variables in the construction.
One way to measure copper temperature is to measure the hot vs. cold resistance of the windings and make a model (because the temperature isn't equally distributed, of course) based on the geometry and the TCR of Cu. It is the hot spot temperature of the wire insulation that matters most.