System for controlling a switch (222; 224) of a voltage converter intended to be connected to a rotating electrical machine, comprising: - a driver designed to supply an output command signal (CMD*; CMD ∗) to the switch (222; 224), the driver being also designed to supply the output command signal (CMD*; CMD ∗) from commands (cmd) received, the driver comprising a first input intended to receive a so-called total inhibition command (INHIB_T) and the driver being also designed, as long as the total inhibition command (INHIB_T) is received on the first input, for the output command signal (CMD*; CMD ∗) to keep the switch (222; 224) open independently of the commands (cmd) received, - a first sensor designed to supply a measurement (V BAT1_1) of a first voltage (V BAT1), - a first monitoring device for monitoring the measurement (V BAT1_1) of the first voltage (V BAT1) designed to supply the total inhibition command (INHIB_T) to the first input of the driver when the measurement (V BAT1_1) of the first voltage (V BAT1) passes below a predefined threshold, characterized in that the driver also comprises a second input intended to receive a so-called partial inhibition command (INHIB_P), in that the driver is also designed, as long as the partial inhibition command (INHIB_P) is received on the second input, to establish the output command signal (CMD*; CMD ∗), independently of the commands (cmd) received, for the rotating electrical machine to be able to operate in alternator mode, and in that it also comprises: - a second sensor designed to supply a measurement (V BFT_2) of a second voltage (V BFT), different from the first voltage (V BAT1), - a second monitoring device for monitoring the measurement (V BFT_2) of the second voltage (V BFT) designed to supply the partial inhibition command (INHIB_P) to the second input of the driver when the measurement (V BFT_2) of the second voltage (V BFT) passes below a predefined threshold. - a driver designed to supply an output command signal (CMD*; CMD ∗) to the switch (222; 224), the driver being also designed to supply the output command signal (CMD*; CMD ∗) from commands (cmd) received, the driver comprising a first input intended to receive a so-called total inhibition command (INHIB_T) and the driver being also designed, as long as the total inhibition command (INHIB_T) is received on the first input, for the output command signal (CMD*; CMD ∗) to keep the switch (222; 224) open independently of the commands (cmd) received, - a first sensor designed to supply a measurement (V BAT1_1) of a first voltage (V BAT1), - a first monitoring device for monitoring the measurement (V BAT1_1) of the first voltage (V BAT1) designed to supply the total inhibition command (INHIB_T) to the first input of the driver when the measurement (V BAT1_1) of the first voltage (V BAT1) passes below a predefined threshold, - a second sensor designed to supply a measurement (V BFT_2) of a second voltage (V BFT), different from the first voltage (V BAT1), - a second monitoring device for monitoring the measurement (V BFT_2) of the second voltage (V BFT) designed to supply the partial inhibition command (INHIB_P) to the second input of the driver when the measurement (V BFT_2) of the second voltage (V BFT) passes below a predefined threshold.