| Abstract |
The paper deals with field-oriented controlled current fed induction machines. The discussed scheme comprises rotor flux space vector estimation on the basis of stator currents and rotor speed measurement. The influence of main flux saturation on rotor flux and slip frequency calculation can be significant during operation in field-weakening region and during rapid accelerations of the drive. As a consequence, discrepancies between actual and estlmated values occur and unsaturated model used in the control part of the drive should be substituted with a convenient saturated model. The paper presents such a model, which can be implemented instead of the nonsaturated one and which takes into account effects of main flux saturation. If this model is applied in the control part of the drive, calculated values of rotor flux amplitude and angular position fit very well with actual values and the desired level of rotor flux can be maintained through the flux regular action, irrespective of the level of saturation. The theoretical results are verified by the aid of digital simulation. |
