CONTROLLING ROTOR VIBRATIONS OF TWO-POLE INDUCTION MACHINE UNDER LOADED OPERATION

摘要

Lateral rotor vibrations of a two-pole induction machine are controlled with a four-pole force actuator that utilizes the concept of a bearingless machine. The actuator changes the magnetic flux distribution in the machine air-gap to produce magnetic force. This has been previously done in no-load operation. When loaded, the spectrum of the vibration becomes more diverse as the rotation frequency of the rotor becomes slower than the rotation frequency of the field. Model based harmonic controllers are used in parallel for the four-pole actuator to remove each vibration frequency. Due to magnetic interactions, one control frequency affects two vibration frequencies. It is not necessary to include the interaction into the control model but, as a result, the number of parallel controllers must be increased to obtain as good results as in no-load. All results are verified with a 30 kW test machine.