A predictive torque control for the synchronous reluctance machine taking into account the magnetic cross saturation

Abstract

A predictive torque and flux control algorithm for the synchronous reluctance machine is presented in this paper. The algorithm realizes a voltage space phasor pre-selection, followed by the computation of the switching instants for the optimum switching space phasors, with the advantages of inherently constant switching frequency and time equidistant implementation on a DSP based system. The criteria how to choose the appropriate voltage space phasor depend on the state of the machine and the deviations of torque and flux at the end of the cycle. In order to obtain an appropriate model of the machine, it has been developed on a d-q frame of coordinates attached to the rotor and takes into account the magnetic saturation in both d-q axes and the cross saturation between both axes. Therefore, the torque dynamic is improved and its ripple is reduced. Simulated and experimental results using a DSP and a commercially available machine show the validity of the proposed control scheme.