Abstract: Control system of a rotor of a permanent magnet generator which comprises a first fixed ring of permanent magnets and a second fixed ring of permanent magnets fixed at opposite ends of a rotor shaft, a first movable ring of permanent magnets movable on a guide axis situated on the side where the first fixed ring of permanent magnets is located and a second movable ring of permanent magnets movable on the guide axis situated on the side where the second fixed ring of permanent magnets is located such that the guide axis is joined to a stator of the generator and where the rotation of the rotor shaft is produced approximating and/or distancing the two movable rings of permanent magnets to and/or from the fixed rings of permanent magnets.