Fuzzy logic based direct torque control of induction motor

ldquoThe design of this project for induction motor can transform the nonlinear torque-speed characteristics of induction motor to constant torque-speed characteristics similar to that of a DC motor.rdquo This project is meant to control the torque of induction motor using fuzzy logic controllers by Direct Torque Control (DTC). DTC method yields slow response during start up and change in either direction of torque and flux. Also large and small errors in flux and torque are not distinguishable so to overcome these drawbacks, fuzzy logic is applied to DTC method. Standard applications account for 70% of all variable speed drives installed throughout industry. Two of the most common applications are in fans and pumps in industries like Heating, Ventilating and Air Conditioning etc. In these applications, DTC provides solutions to problems like harmonics and noise. In this project we have used fuzzy logic based duty ratio controller whose optimum duty ratio is determined every switching period for the inverter. The simulation of the project is done by programming in Matlab. The computer simulated results verify the validity of this novel method.