Predictive direct flux vector control of Permanent Magnet Synchronous Motor drives

This paper investigates a direct flux vector control strategy with minimum need of calibration, suitable for Permanent Magnet Synchronous Motor drives. The proposed controller operates in stator flux coordinates, guaranteeing the full exploitation of the inverter current and voltage limits via compact on-line computations. The reference voltage vector is obtained by means of explicit equations coming from the magnetic model of the machine, and the algorithm is insensitive to motor parameter variations, since the stator inductances are adaptively evaluated at each sample time from the observed flux components. Thus, the proposed algorithm applies to all PM machines, more or less salient or saturated, with no need of regulators tuning. Experimental tests are presented for a PM-Assisted Synchronous motor drive. Results with standard control techniques, based on proportional-integral regulators, are also reported, for the sake of comparison.