On field-oriented control of induction motors: tuning of the PI gains for performance enhancement

We have previously shown that field-oriented controllers for induction motors preserve stability under a wide range of variations of the motor and controller parameters. However, as is well known, the transient performance critically depends on the tuning of the gains of the PI velocity loop, a task which is rendered difficult because of the high uncertainty on the rotor time constant. The problem we address in this paper is how to develop an off-line procedure to choose these gains. The main contribution of our work is a very simple algorithm that, for each setting of the PI gains, evaluates the maximum error of the rotor time-constant estimate for which global stability is guaranteed