DEVICE AND METHOD FOR MONITORING AND/OR ANALYZING ROTORS OF ELECTRIC MACHINES IN OPERATION

摘要

The invention relates to a method for monitoring and/or analyzing electric machines in operation, wherein an electric machine comprises at least one generator having a shaft, an excitation system, and drive means for driving said shaft. A first signal, which describes a voltage across a rotor winding, and a second signal, which describes a current flowing through the rotor winding, are measured simultaneously. The two signals are fed to an analysis unit. In the analysis unit, the signals are divided into individual frequency components. Then, the impedance of the rotor winding is determined in order to detect error states in the electric machine.