Studies on Direct Torque Control-Based Speed Control of Three-Phase Squirrel-Cage Induction Motor

Direct torque control (DTC) is the simplest method meant for torque control of a three-phase induction motor. The present study emphasizes speed control by using an external speed loop with DTC controller. The variable torque command is generated from the speed loop using a conventional PI controller which has been implemented in experimental work to validate the simulation results. A fuzzy rule-based speed controller has been developed in this study for comparison purpose. The speed response is faster using conventional PI controller, but fuzzy controller minimizes the ripple content in torque. The design of the speed controller has been made economical by using low-cost discrete electronic hardware components.