1. Main operating modes

The operating modes can be characterized by the principle of obtaining the synchronism condition, by controlling or not the frequency of the rotating armature and inductor fields.

We distinguish (figure 1 ) :

• free-frequency mode: in this case, we find autonomous generator operation in which the armature winding currents result from the flow in a load and are therefore naturally at a frequency directly linked to the rotation frequency by the number of pole pairs 3