3. Iron losses

3.1 Alternating flux magnetic circuit

In most electromagnetic systems, such as transformers, inductors, transducers, motors and generators, the magnetic flux is alternately or transiently variable. Since ferromagnetic materials are conductive and characterized by hysteresis, any variable flux generates losses:

• by hysteresis ;

• by eddy currents in the conductive structure.

Consequently, measures relating to the choice of materials and the structure of the magnetic circuit must be taken to minimize these losses. A simplified analysis of these losses shows the laws of variation as a function of the characteristic parameters: frequency and induction. It also provides indications...