Abstract
The electromagnetic force acts between the rotor and
stator of an induction motor, when the rotor is
performing cylindrical circular whirling motion with
respect to the stator. The non-symmetric flux
distribution due to the eccentricity induces circulating
currents in the rotor cage and parallel branches of the
stator winding. These currents tend to equalize the flux
distribution, and by doing this, reduce the
electromagnetic force and change the direction of the
force from the direction of the shortest air gap.
Impulse method is utilized in the finite element analysis
to calculate the frequency response of the force and the
eccentricity harmonics of the flux density in the air gap
and the circulating currents. The frequency responses
were calculated for the test motors with different stator
connections and with and without rotor cage.
The frequency response function of the force is
calculated for two induction motors with different
geometry, one with open and another one with closed rotor
slots. The results show that the equalizing currents in
both parallel branches in the stator winding and rotor
cage damp strongly the amplitude of the force. The
damping effects depend on the whirling frequency, loading
condition and the geometry of the machine.
| Original language | English |
|---|---|
| Title of host publication | IEEE International Electric Machines and Drives Conference, 2003 (IEMDC'03) |
| Publisher | IEEE Institute of Electrical and Electronic Engineers |
| Pages | 257-263 |
| ISBN (Print) | 0-7803-7817-2 |
| Publication status | Published - 2003 |
| MoE publication type | A4 Article in a conference publication |
| Event | 2003 IEEE International Electric Machines and Drives Conference, IEMDC - Madison, United States Duration: 1 Jun 2003 → 4 Jun 2003 |
Conference
| Conference | 2003 IEEE International Electric Machines and Drives Conference, IEMDC |
|---|---|
| Country/Territory | United States |
| City | Madison |
| Period | 1/06/03 → 4/06/03 |
Keywords
- electrical machines
- equalising currents
- electromagnetic forces
- rotor eccentricity
- impulse method