A Novel Lookup Table Based Direct Torque Control for OW-PMSM Drives

Abstract

In this letter, a novel lookup table (LUT)-based direct torque control (DTC) strategy is proposed for dual-inverter fed open winding permanent magnet synchronous motor drives. Torque and flux linkage are regulated by tracking the reference voltage vector (VV) on the space VV plane according to a simplified LUT. The simplified LUT is established by dividing the space VV plane into 19 regions and each region corresponds to a basic VV. The optimal VV can be obtained by locating the corresponding region of the reference VV, which significantly decreases the complexity of LUT design and maintains the simplicity of the DTC strategy. A group of optimal switching states that minimize the transition times is selected. Meanwhile, the elimination of the hysteresis controller can further decrease the switching frequency. Experimental results show that the torque ripple, current harmonics, and switching frequency of the proposed strategy are reduced compared with the traditional DTC strategy.