The invention relates to a system for generating electric power, comprising: an alternator (1) for coupling with a drive system (7), supplying an AC voltage to an output bus (10); a reversible AC/DC converter (2) in which the AC bus (6) is connected to the output bus (10) of the alternator (1); an electricity-storage element (3) connected to the DC bus (9) of the converter (2); a controller (4) arranged to react to a transient state of load-shedding or charging impact by controlling the converter (2) so as to collect energy on the output bus (10) of the alternator (2) and to store same in the storage element (3) in the case of load-shedding, and to collect energy in the storage element (3) and to inject same into the output bus (10) in the case of charging impact, the converter (2) being controlled so as to inject currents to compensate for harmonic currents into the AC bus (10) of the alternator (1).