Abstracto

Direct Torque Control of Induction Motor Drive Using Pi-Fuzz y Logic Controller

Venkatesh.G , Bagavathy.S

Direct Torque Control (DTC) of an induction motor fed by a voltage source inverter is a simple scheme that does not need long computation time and can be implanted without mechanical speed sensors and is insensitive to parameter variations. In principle, the motor terminal voltages and currents are sampled and used to estimate the motor flux and torque. Based on estimates of the flux position and the instantaneous errors in torque and stator flux magnitude, a voltage vector is selected to restrict the torque and the flux errors within their respective torque and flux hysteresis bands. In the conventional DTC, the selected voltage vector is applied for the whole switching period regardless of the magnitude of the torque error. This can result in high torque ripple. This paper aims in comparison of different techniques followed for torque ripple minimization in induction motor drive.