V/F Controlled Induction Motor Drive Using Advanced Microcontroller

Abstract

Recent advances in semiconductor technology and implementation of fast microcontroller have made it easier to use AC motors for speed control application. This report focuses on performance analysis of V/F controlled induction motor drive. The most basic requirement for implementation of this V/F control scheme is the PWM Inverter controlling Induction Motor drives. Simulation analysis of this drive is carried out using MATLAB. Both open-loop V/F control as well as closed-loop V/F control method of speed control is studied. Performance of the presented drive is studied for various rotor speeds due to the change in load side on a PWM-Inverter fed 3-phase Induction Motor. It is observed that with the help of Closed-Loop topology with a Proportional Controller, we can control the speed in a very precise manner while maintaining a constant maximum torque. In this model, to obtain variable speeds, the actual speed of motor is compared with reference speed. The difference in speed is adjusted by changing firing angles of switching devices and thereby obtaining variable speeds. Steady state as well as transient analysis of the drive is presented in this report. Hardware implementation of a two-level converter fed induction motor is carried out.