DC copper loss caused by the DC Resistance (DCR) of the windings. It increases proportionally to the square of the current.
AC copper loss caused by the AC Resistance (ACR). The AC resistance depends on the frequency and is based on
skin effect: The higher the frequency the lower the skin depth. As the frequency becomes higher, there is a tendency for the current flow to become concentrated in the area near the conductor surface and for the effective resistance value to increase.
proximity effect: The proximity effect increases the AC resistance as well. A current driven wire creates a magnetic field around the wire, which also creates a magnetic field around the wire, which also creates eddy currents.
Core loss
Hysteresis loss
Eddy Current loss. Eddy current loss is proportional to the square of the frequency.
