Optimal Torque Control of Saturated Synchronous Motors: Plug-and-Play Method

Abstract

This paper deals with the optimal state reference calculation for synchronous motors having a magnetically salient rotor. A lookup table computation method for the maximum torque-per-ampere locus, maximum torque-per-volt limit, and field-weakening operation is presented. The proposed method can be used during the start up of a drive, after the magnetic model identification. It is computationally efficient enough to be implemented directly in the embedded processor of the drive. When combined with an identification method for the magnetic model, the proposed method enables the plug-and-play startup of an unknown motor. Furthermore, a conventional reference calculation scheme is improved by removing the need for one two-dimensional lookup table. A 6.7-kW synchronous reluctance motor drive is used for experimental validation.