Patent ID: 8618759

Claim:
A method for heating of robots in cold environments, comprising: providing a robot with permanent magnet brushless or three-phase synchronous motors with three motor phases including three stator coils (L 1 , L 2 , L 3 ) connected to an inverter controllable by a control-unit and with a rotor with permanent magnet excitation; applying a current to at least one phase stator coil (L 1 , L 2 , L 3 ) of the motor when the motor stands still to create a directed magnetic flux (Î¦) which interacts with permanent magnets of the rotor in such a way that a resulting torque will be close to zero wherein the current is a DC-current or a pulsed DC-current (I 0 ) controlled by a current regulator; measuring the rotor position by a rotor-position-sensor; and creating a first static directed DC-stator-current (I 0 *x) flowing through stator coil L 1 and a second static directed DC-stator-current (I 0 *y) flowing through strator coil L 3 , that generate a directed magnetic flux (Î¦) which is aligned with the rotor flux.