Method and apparatus for on-line tracking of the thermal load of an electric motor

The invention claims a device for revolving during operation tracking the thermal load of an electric motor (M) by the rotation of its rotor (T) comprising: - measured during operation of the electric motor to receive a control unit (C) which is adapted, based on the electricity and / or on the kinetics of the electric motor measured data and derived by means of one of a predetermined engine geometry (G) mathematical model of physical quantities of the contact following to determine the overall condition of the engine and the measured data as input data in real time at least one approximate to a fictive real value temperature value and a temperature profile is dependent on the overall condition of the engine and / or depending on the configuration of the motor to define a cooling period for reducing the thermal load of the electric motor predict, the undergoes a resultant of the follower determining approximate temperature value as an initial value in the temperature profile to be forecast from the least, and - a release unit (R) for enabling a further and / or re-operation of the electric motor after expiration of the predicted cooling period.