Patent ID: 8587229

Claim:
A method for braking a thermal engine of a motor vehicle using a reversible multi-phase rotating electrical machine ( 1 ) connected to the thermal engine and comprising a stator ( 16 ), a rotor ( 4 ) comprising at least one field coil ( 41 ) and a voltage regulator driving the at least one field coil ( 41 ) of the rotor ( 4 ), the method comprising the steps of: short-circuiting at least one phase of the rotating electrical machine during a stop phase of the thermal engine; exciting the at least one field coil ( 41 ) of the rotor ( 4 ) by the regulator during the stop phase of the thermal engine so as to generate a resistive torque on the rotor; pre-magnetizing the rotor; and varying the supply of current to the field coil so that the PWM voltage duty cycle of the voltage regulator increases from a first predetermined value to the maximum duty cycle value while the speed of the thermal engine shaft decreases from a first predetermined speed value to a second predetermined speed and the PWM voltage duty cycle of the voltage regulator stays at the maximum duty cycle value while the speed of the thermal engine shaft decreases from a second predetermined speed value to a third predetermined speed.