Electric propulsion system

The electric drive system - a generator mode or motor-operated electric drive unit (101; 201; 301), - a prime mover connected with the frequency converter (102; 202; 302), - a drive machine and the frequency converter comprising housing (100; 200; 300), - at least one fan wheel (103; 231, 232; 331, 332), characterized, in that is provided, the actuation of an operating state of the prime mover and / or the frequency converter is configured dependent, a fan wheel to a rotor shaft (111; 211;; 311) - the drive machine separable coupling clutch (233 131) - the clutch is designed such that the fan wheel is disengaged at a temperature above a predetermined threshold value rotor speed of the rotor shaft.