Institute of Electrodynamics, National Academy of Sciences of Ukraine
The field-oriented control (FOC) method is a widely used technique for precise speed regulation in three-phase induction motor drives. The resistance values of the motor vary from their rated values because of increased temperature during operation. The research aims to improve the accuracy of rotor flux linkage (RFL) estimation, thereby sustaining the performance of the FOC method under resistance variations. The paper proposes a more advanced approach to estimating and integrating motor resistances into the RFL calculation. A new structure, featuring voltage, current, and virtual current models, is used to determine the stator and rotor resistance. These estimated resistance values replace the rated resistance values in the current model, which are then used to calculate the RFL vector. Simulations are performed to verify the accuracy of the estimated resistance values and the effectiveness of the improved FOC method under different operating conditions. The simulation results demonstrate that the calculated resistances closely match the preset resistance values, confirming that the enhanced FOC method retains high estimation accuracy even when motor resistance changes. References 18, figures 9.
