Performance enhancement of Direct Torque Control IM drive using Genetic Algorithm

The speed of three phase Induction Motor (IM) drives are controlled with the help of vector control and scalar control. Direct Torque Control (DTC) is advanced scalar control technique for speed control of IM drives. Fast response, dynamic performance and robustness has made DTC very popular. The Conventional DTC drive requires no coordinate transformation and therefore its control algorithm becomes simple. However it has high torque ripple and slow transient response because of the use of hysteresis controllers in torque and flux loop. In this paper modified DTC scheme for IM drive is proposed where three proportional integral (PI) controllers are introduced to replace the hysteresis controllers. The outer loop having PI speed controller is tuned using Genetic Algorithm (GA) for improving the speed and torque response of the drive.