Performance Comparison between Conventional PI and PI-Like Fuzzy Speed Controller for Three Phase Induction Motor

Three-phase induction motor (IM) plays a very important role in today's industry due to its robustness, compact size, low cost, little maintenance requirement, and other features that give it advantage over other types of motors. In industrial applications, it is very important to have a control over IM speed to get a steady response. In this work, dynamic model of three phase induction motor is introduced and simulated using (direct-quadrature) dq transformation in stationary reference frame. Fuzzy logic Controller (FLC) is designed and compared with conventional Proportional Integral (PI) controller. Speed error and its integral are used as inputs to the controller where change in frequency is the output obtained and fed to the inverter to regulate its frequency in order to achieve the desired voltages which control the speed of motor. From results, it is shown that the performance of IM with FLC is more stable than with conventional PI, the speed almost has to be constant even though load torque is applied at specific instant because of the instantaneous response of FLC