Direct Torque Control Based Two Quadrant Analog Torque Controller for Squirrel Cage Induction Motor

High performance variable speed drives have become indispensable for the modern age industry where the product quality and productivity are of utmost importance. Because of the many drawbacks of dc drives, research attention has been focused toward ac drives, mainly induction motor drives. The ac drives have evolved over the years with improved transient torque output response that closely matches the response obtained from dc drives. This paper presents a complete hardware based two quadrant analog torque controller for squirrel cage induction motor based on the Direct Torque Control (DTC) scheme. The proposed analog torque controller may find its own niche area of application, for example, in packaging industries where mostly small and medium sized drives are used. The two quadrant analog torque controller has been implemented as a simple hardware circuit based on the DTC scheme. The implementation is done using commonly available low-cost hardware components.