Two adaptive nonlinear control schemes for an induction motor

Two adaptive nonlinear control schemes are presented for an induction motor: tuning function and modular design approaches. The objective here is to control the speed and flux in an independent manner despite rotor resistance uncertainty. In most existing adaptive schemes with this objective, load torque is regarded as a constant but unknown parameter to be estimated rather than a disturbance. On the other hand, this paper uses an integrator to deal with the low-frequency load torque instead of trying to estimate it. Simulations show that the proposed adaptive schemes lead to uniform closed-loop performance despite the uncertainty of the rotor resistance. Copyright(C) 1998 IFAC.