Verfahren zum Schutz von Gleichstrommotoren vor thermischer Überlastung

摘要

The invention relates to a method for protecting direct current motors from thermal overload. According to the invention, a temperature of the direct current motor is detected and compared with a predetermined maximum temperature. In the event that the maximum temperature is exceeded, the voltage supply of the direct current motor is interrupted. A rotor temperature (TR) of the direct current motor (10) is determined from an armature current (IA) and an ambient temperature (TM) of said direct current motor (10). Said rotor temperature (TR) is compared with a maximum allowable temperature (Tmax), and a supply voltage is timed by a control unit (26) in accordance with this comparison between the rotor temperature (TR) and the maximum admissible temperature (Tmax), said control unit providing the supply voltage to the direct current motor (10).