System and method for controlling the power supply of an electric machine on the basis of the temperature thereof

A control system for controlling a supply of power to an electric machine of a motor vehicle and which contributes to propulsion of the vehicle, the control system being connected at an input to an estimating means for estimating a temperature of a rotor of the electric machine and to a temperature sensor that measures a temperature of a stator of the electric machine, the control system comprising:

• a first currents map that is optimized for limiting electrical losses;
• a second currents map that is optimized for reducing losses in the rotor and increasing losses in the stator;
• and
• a third currents map that is optimized for increasing losses in the rotor and decreasing losses in the stator;
• the maps containing a set of values that make it possible to determine electric machine supply currents on the basis of torque and rotational speed request values received at the input to the control system;
• the control system further comprising a switchover means configured to choose the map, the supply current signals of which are transmitted to the electric machine on the basis of the signals from the means of estimating the temperature of the rotor and from the stator temperature sensor.

A method for controlling a supply of power to an electric machine of a motor vehicle and which contributes to propulsion of the vehicle, the electric machine including a rotor including a means of estimating temperature and a stator including a temperature sensor, the method comprising:

• receiving an electric machine torque and rotational speed request;
• determining a temperature of the stator and a temperature of the rotor;
• determining a difference between the temperature of the stator and the temperature of the rotor;
• determining at least two electric machine supply current values that satisfy the torque and rotational speed request;
• choosing a supply current value on the basis of the temperature of the stator and of the temperature of the rotor so that if the rotor temperature is above a value of a first threshold and the difference between the rotor temperature and the stator temperature is above a value of a second threshold, the value chosen is a value from the electric machine supply currents that are optimized for reducing losses in the rotor and increasing losses in the stator;
• and
• transmitting the chosen value to the electric machine.