Monitoring Device for a Double-Fed Asynchronous Machine

A double-fed electrodynamic asynchronous machine comprising:

• a monitoring device;
• a stator and a rotor body held rotatably therein, whose shaft is mounted on at least one bearing;
• at least one insulation layer for electrical insulation of the rotor body with respect to a zero potential;
• at least one contact element for tapping an electric voltage, which is applied with respect to the zero potential using said at last one insulation layer;
• a measuring and signalling unit, which is connected to the contact elements for measuring the applied voltage and is designed for emitting a warning signal depending on the height of said voltage;
• wherein said at least one bearing comprises an annular first insulation layer, and wherein a second annular insulation layer is arranged between said at least one bearing and the shaft, wherein the voltage is tapped with respect to the zero potential via the first insulation layer.

A method for monitoring a double-fed electrodynamic asynchronous machine having a stator and a rotor body held rotatably therein, whose shaft is mounted on at least one bearing, and having at least one insulation layer for electrical insulation of the rotor body with respect to a zero potential, in which a second annular insulation layer is arranged between said at least one bearing and the shaft, the method comprising:

• measuring an electric voltage;
• applying said electric voltage with respect to the zero potential using the insulation layer;
• and
• emitting a warning signal depending on the height of said electric voltage.