Performance Evaluation of Membership Functions on Fuzzy Logic Controlled AC Voltage Controller for Speed Control of Induction Motor Drive

objective of this paper is to investigate the effect of membership functions in the fuzzy control (FC) of an ac voltage controller for speed control of induction motor drive. A Sugeno type FC for closed loop control of induction motor drive fed by ac voltage controller is designed and considered for evaluation. The controller is used to change the firing angle of the ac volage controller and thereby, the voltage fed to stator of induction motor to regulate the speed. Sugeno type FC is selected for evaluation, as it is easy to implement in simulation. The membership functions selected for evaluation are triangular, trapezoidal, Gaussian and bell shaped functions. The different membership function evaluation is done considering seven linguistic sets for error and change in error. The simulation model of different membership functions in the fuzzy control (FC) of an ac voltage controller for speed control of induction motor drive is implemented in Matlab/simulink The results of the simulated performances are compared. The triangular membership function shows better performance compared to other membership functions.