An Improved Robust Field-Weakeaning Algorithm for Direct-Torque-Controlled Synchronous-Reluctance-Motor Drives

This paper presents an improved field weakening (FW) algorithm for synchronous-reluctance-motor drives. The proposed algorithm is robust to the variations in the machine d- and q-axis inductances. The transition between the maximum torque per ampere, current and voltage limits, and the maximum torque per flux trajectories is smooth. The proposed technique is combined with the direct-torque-control method to attain a high performance drive in the FW region. Simulation and experimental results are supplemented to verify the effectiveness of the proposed approach.