A COMPARATIVE STUDY OF PROPORTIONAL INTEGRAL CONTROLLER AND FUZZY LOGIC CONTROLLER IN SCALAR SPEED CONTROL OF THREE PHASE INDUCTION MOTOR

This paper presents a performance study of the proportionalintegral controller andthe fuzzy logic controller in scalar speed control of three phase squirrel cage induction motor drive. Here the speed control is possible by varying supply frequencyusing a voltage source inverter while keeping voltage to frequency ratio as a constant. Speed error is given as inputto the proportional integral controller, and speed error and change in speed error are given as input to the fuzzy logic controller.The controller output controls the reference of sinusoidal pulse width modulation. Hence, the fundamental frequency and fundamental voltage of inverter output can be varied to control the motor speed.The performance of proportional integral controller and fuzzy logic controller underload torqueand reference speed variationisevaluated by simulation results in Simulink.