Motor temperature control using estimated motor temperature based on motor power dissipation

A system for limiting motor temperature, comprising:

• an ambient temperature sensor operable to sense ambient temperature near the motor and supply an ambient temperature signal representative thereof;
• motor power dissipation determination means, responsive to motor commands, for supplying a motor power dissipation signal representative of power dissipation by the motor;
• thermal model means, responsive to the ambient temperature signal and the motor power dissipation signal, for (i) estimating motor winding temperature and (ii) supplying a motor winding temperature signal representative thereof;
• power dissipation limit determination means, responsive to the motor winding temperature signal, for (i) determining a maximum motor power that, when supplied to the motor, would raise the motor temperature to a predetermined maximum temperature value in a predetermined time period and (ii) supplying a motor power dissipation limit signal representative thereof;
• and
• limiter means, responsive to the motor power dissipation limit signal, for limiting the motor commands supplied to the motor based on the determined motor power dissipation limit signal.

A flight control surface actuation system, comprising:

• an actuator motor coupled to receive actuator motor commands and configured, upon receipt thereof, to supply a drive force;
• a flight control surface actuator coupled to receive the drive force and operable, upon receipt thereof, to move to a commanded position;
• an ambient temperature sensor operable to sense ambient temperature near the actuator motor and supply an ambient temperature signal representative thereof;
• and
• an actuator controller coupled to receive the ambient temperature signal and adapted to receive flight surface position commands, the actuator controller operable, in response to the ambient temperature signal and the flight control surface position commands, to supply the actuator motor commands to the actuator motor and limit actuator motor temperature to a predetermined maximum temperature, the actuator controller including:
• motor power dissipation determination means, responsive to the actuator motor commands, for supplying a motor power dissipation signal representative of power dissipation by the motor;
• thermal model means, responsive to the ambient temperature signal and the motor power dissipation signal, for (i) estimating motor winding temperature and (ii) supplying a motor winding temperature signal representative thereof, respectively;
• maximum power dissipation determination means, responsive to the motor winding temperature signal, for (i) determining a maximum actuator motor power that, when supplied to the actuator motor, would raise the actuator motor temperature to the predetermined maximum temperature value in a predetermined time period and (ii) supplying a maximum actuator motor power dissipation signal representative thereof;
• and
• limiter means, responsive to the maximum actuator motor power dissipation signal, for limiting the actuator motor commands supplied to the actuator motor based on the determined maximum actuator motor power.