Micro-controller based closed loop control of induction motor using V/F method

Recent advances in semi-conductor technology and implementation of micro-controller have made it easier to use AC Motors in speed control applications. The proposed paper, deals with variable speed drives of induction motor for constant torque using V/F ratio method. The above system is designed with closed loop where the actual speed of motor is compared with the reference speed. The difference in the speed is adjusted by changing firing angles of switching devices and there by obtaining variable speeds. The system is tested for its performance and is also recorded under various conditions. Introduction of microcontroller in performing the speed control of the induction motor makes it more flexible when compared with other traditional methods.