Method for protecting stator winding and rotor winding or rotor cage of electrical machines against undue heating, involves electronically identifying time characteristics of temperature in stator winding and rotor winding and rotor cage

摘要

The method involves electronically identifying the time characteristics of the temperatures in a stator winding (delta T1) and a rotor winding (delta T2) and a rotor cage, and generating a warning signal. A temperature model (4) is provided, which consists of heat sources, heating resistance and heat storage capacitances. A warning signal is provided to shutdown or to reduce the power of the electrical machine, when a specified temperature limit for the stator winding and the rotor winding and the rotor cage is exceeded.