Synchronous machine with a superconducting voltage and speed regulator

In a synchronous electric machine having a voltage and speed regulator, said machine comprising a stator provided with a secondary winding and a rotor provided with a primary winding, intended for connection to a feeder grid (operating as a motor) or a user grid (operating as an alternator), the improvement wherein the stator winding (ES) is coupled with a second stator winding (e), a static rectifier circuit (R) is connected on its input side to said second stator winding (e), said static rectifier is connected on its output side to a superconducting energy storage winding (BS), and a computer (C) is connected to the rectifier circuit such that rectifier is controlled by said computer (C) programmed to inject active and reactive power into the stator in such a manner as to attenuate transient conditions.