Performance Analysis of Direct Torque Control of PMSM Drive Using Two Level Inverter

Permanent Magnet synchronous motors (PMSM´s) are widely used in high-performance drives such as industrial robots and machine tools. It has characteristics of high efficiency, simple structure, high torque/inertia ratio, maintenance free and easy to control. The high torque density and high efficiency make PMSM as a better option as compared to induction motor drive. The torque in PMSM is usually controlled by controlling the armature current due to the fact that the electromagnetic torque is proportional to the armature current. The direct torque control (DTC) technique for a PMSM motor is receiving increasing attention due to the important advantages as the elimination of the current controllers and the low dependence on motor parameters when compared with other motor control techniques. The basic principle of DTC is to directly select stator voltage vectors according to the differences between the references of torque and stator flux linkage and their actual values. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation model is developed in MATLAB/SIMULINK is used to verify the performance of the PMSM drive using two level inverter.