Fuzzy logic controlled variable frequency drives

Abstract

In this paper, a fuzzy-based PWM controller has been proposed for performance and efficiency enhancement in variable frequency drives (VFD). The VFDs are used for controlling operation of induction motors which are generally nonlinear in nature. The nonlinear loads are major cause of harmonics in the power supply and needs attention. In the present paper, a fuzzy-based closed-loop system for PWM-controlled VFD has been developed. The fuzzy rule base has been designed considering the instantaneous values of rotor speed for the speed change fuzzy input. The closed-loop motor control system is designed in MATLAB/Simulink environment for analysis. It is clear from the results that there is a significant improvement in the performance of closed-loop drive.