To provide an electric driving machine having driving and energy-transferring functions having an extended range of functions.

In the electric machine (15) having a common active portion deduced from a stator and rotor having windings and/or permanent magnets for driving and energy-transferring functions, a rotor winding existent for energy transferring can be so utilized as to detect a rotor position by a little additional cost. For the purpose, an electric power converter present in the rotor and for an energy-transferring function which is used for taking-out an electric energy applies an AC voltage to the rotor winding so as to detect the AC voltage and so as to detect the rotor position.