Performance Improvement of Induction Motor using Direct Torque Cotrol

For the application of drives with variable speed, DC machines were largely utilized from several years. It is chiefly, because of the reduced control over coupling between flux and torque. It can be attained by controlling the armature current and thereby field. Electrical DC Machines are substantially utilized for the applications of changeable speed to provide a quicker and excellent active response over torque due to consistently stable torque angle by commutator. Still, DC machines possess two main drawbacks. Firstly, the mechanical construction of brush and another one is commutator. As in the result, regular maintenance becomes must and it restricts the DC machines usage in the rapid and unstable applications. On the other hand, AC Machines possess numerous benefits as comparing to DC machines. These are rugged, involve lesser maintenance, inexpensive and high speed performance. Fundamentally, the controlling techniques of AC machines can be categorized, as the controls of scalar and vector. The amplitude and frequency of space vectors of current, voltage, and flux linkage are regulated in the scalar control.