Novel flux weakening control algorithm for PMSMS

This paper proposes a novel algorithm to generate the optimum d- and q-axis current reference for the drive system of PMSMS (permanent magnet synchronous motor with sinusoidal excitation) in the entire flux weakening region and also to generate the limits of PI speed controller. The algorithm offers optimum torque capability for PMSMS despite significant changes in dc link voltage and machine parameters. This algorithm can be easy integrated in the field oriented control of PMSMS with or without mechanical sensors, but also in scalar control algorithm (without motor current measurement). The control identifies when the machine enters in the flux weakening region and adjust the d- and q-axis current reference according to the dc link voltage. The experimental results show that the proposed algorithm provides good steady state and dynamic performance.