Improved vector control of an induction motor with on-line tuning of its parameters

It has reported that the parameters of an induction motor are varied according to the change of operating condition. The indirect rotor flux-oriented control system is sensitive to the variations of inductances. So there are detuned effects in torque and flux. They are remarkable in the field-weakening region. In this paper, a simple online tuning scheme for indirect rotor flux-oriented control systems is proposed. Detuned effects caused by inductance variations are shown and a simple online tuning scheme of them is proposed. Inductances are identified and tuned by only stator flux and stator current. The proposed scheme is effective not only in the constant torque region but also in the field-weakening region. The proposed online tuning scheme is confirmed by the simulation and experiment results