A Modification Of Direct Torque Control For High- Efficiency And Quick Responses Induction Machine

Kamarrudin, Dieza Fayyadha (2015) A Modification Of Direct Torque Control For High- Efficiency And Quick Responses Induction Machine. Project Report. UTeM, Melaka, Malaysia. (Submitted)

Text (24 Pages) A Modification Of Direct Torque Control For High- Efficiency And Quick Responses Induction Machine.pdf - Submitted Version Download (456kB)

Abstract

This report presents a modification of conventional Direct Torque Control (DTC) scheme of induction machine. DTC is well-known because its method has widely been acceptance for advanced motor control in many industrial applications due to its simplicity and high-torque control performance. Despite its simplicity, the DTC has some major problems which are larger torque ripples, variable switching frequency due to the hysteresis controllers used for torque and flux hysteresis comparator and inaccurate the stator flux estimator because of used the pure integrator hence can decrease the drive performance of induction motor. The research project aims to minimize switching frequency and hence switching losses by modifying the DTC structure. Thus, the flux locus can be controlled to form a hexagonal shape. The changing of the flux locus from circular to hexagonal locus shape which can obtained by modifying the flux status error of the hysteresis controller.Therefore, the selection of appropriate voltage vectors is needed to follow the requirement of output signal of the comparator. By doing this proposed strategy, the bandwidth of hysteresis as well as the torque ripple can be regulated within its band which can solved the problem of switching frequency. The modification of DTC and the improvements via experimental results were verified.

Actions (login required)

View Item