A modified direct torque control of IPM synchronous machine drive with constant switching frequency and low ripple in torque

A modified direct torque control (DTC) scheme for interior permanent magnet synchronous machine (IPMSM) is investigated in this paper, which features in very low flux and torque ripple and almost fixed switching frequency. The new scheme provides a variable option for the improvement of DTC controlled IPMSM. Two PI controllers regulate the flux and torque respectively and the stator voltage is generated through SVM unit in the proposed DTC system. Simulation results show that the performance of the proposed DTC system has been improved and the flux and torque ripples are greatly reduced with respect to the conventional DTC.