Rolls-royce Deutschland Ltd & Co. Kg

Dieter Cramer

Christian Stanek

Johannes Heissenberger

An electric machine includes a rotor, a stator, and an air gap formed between a magnetic device of the rotor and the stator. For the selective setting of the air gap, movement devices implemented by piezoelectric stacks are provided on the rotor and/or on the stator. The movement devices may influence radial positions of the respective magnetic device and thus set the radial air gap width. It is thereby possible to exert open-loop and/or closed-loop control over a power or torque of the electric machine without adjusting stator currents. Vibration or unbalance of the rotor may also be counteracted quickly and effectively during operation of the machine.

Electric machine with an adjustable air gap

The disclosure relates to an electric machine and in particular to the monitoring of the electric machine for the presence of a fault, (e.g., in the stator windings). A monitoring unit is provided, wherein the monitoring unit measures the multiphase electrical time signals transmitted from or to the machine and with the aid of a Hilbert filter determines substantially in real time the envelopes and the phase positions of the individual phases of the time signal. The envelopes corresponding to the different phases or the corresponding phase positions are compared with one another by way of forming differences and, in the event that one or more of the differences deviate(s) from a specified expectation value, the presence of a fault is inferred. The approach allows significantly increased operational reliability of the electric machine to be achieved in particular.

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Munich, Germany

Dieter Cramer