Research on DTC of Permanent Magnet Synchronous Motor Without Flux Linkage Loop

In this paper, a direct torque control (DTC) method without flux linkage loop is investigated for permanent magnet synchronous motor (PMSM). In this proposed DTC, the proper voltage vectors are selected according to the sector position of rotor flux to control the torque directly. Therefore, the flux linkage loop to keep a constant amplitude of stator flux is eliminated. The space voltage vectors with varying rotor and stator flux positions are first analyzed. The switching table for this method is optimized based on the analysis above. The comparison between this method and traditional DTC is carried out on a prototype motor. The experimental results show that the proposed DTC is simple and can effectively provide accurate torque control with reduced torque ripple and quick dynamic performance.