Exact tracking by dynamic field-weakened PMAC servodrive

In the paper the exact tracking of permanent magnet AC servodrives with dyn amic field-weakening is presented, The analytical solution given in the for m of a reference dynamic model of the direct axis current and corresponding transition conditions is derived from the inverse motor dynamics. The pres ented solution guarantees the control voltage to remain within the constrai nt during steady states and transients, and also preserves exact tracking o f the prescribed mechanical trajectories in the held weakening mode. The su ggested method is independent of the implemented control structure. Analyti cal results have been confirmed by the experiments.