A system and method for controlling a multiphase electric motor fitted to a motor vehicle. The motor includes a rotor powered by a voltage chopper or a rotor with permanent magnets and a stator powered by a multiphase voltage inverter. The multiphase voltage inverter is powered via a high-voltage DC bus. The control system receives as an input a torque setpoint of an electric-vehicle computer. The system also includes a system for the dynamic control of the torque setpoint to determine a dynamic correction of torque ripple and a device for determining setpoints for powering the electric motor as a function of the torque setpoint and of the dynamic correction of torque ripple.