Implementation of 6 Sector Methodologies Based Direct Torque Control for PMSM

-Permanent Magnet Synchronous Motor (PMSM) is widely used in high–performance drives such as industrial robots and machine tools. It characteristics of high efficiency, simple structure, higher torque /inertia ratio, maintenance free and easy to control. The higher torque density and high efficiency make PMSM as a better option as compared to induction motor. The torque in PMSM is usually controlled by controlling the armature current due to the fact that the electromagnetic torque is proportional to the stator 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 .In this proposed work a modified DTC for PMSM to reduce torque ripples and flux ripples is proposed. This is achieved by replacing two level inverter by three level inverter in classical DTC, also the new switching table is proposed by combining, different voltage vectors available. Such as large, medium, small, zero. The proposed method is simulated in Matlab/simulink environment. The simulated result analysis indicates that the proposed method is able to diminish the torque as compared to classical DTC [1].