An Improved Direct Torque Control of Surface Permanent Magnet Synchronous Motor Drives Using Space Vector Modulation

In this paper, an improved direct torque control (DTC) scheme for surface permanent magnet synchronous machine (SPM) is investigated, which features in very low flux and torque ripple and almost fixed switching frequency. It is based on the deadbeat control of the flux and torque. Simulation and experimental results show that the flux and torque ripples are greatly reduced when compared with those of the basic DTC. With the new scheme, the quick dynamic torque response of the basic DTC is still retained. Fixed switching frequency at different operating conditions becomes possible by means of space vector modulation.