Experimental DTC of an Induction Motor Applied to Optimize a Tracking System

Abstract

In recent years, the areas of industrial application of high performance AC drives, especially the induction motor (IM), based on Direct Torque Controller (DTC) technique has gradually increased due to its advantages over the other techniques of control. Among these applications are cited, propulsion and tracking systems. This work presents the experimental part of a research project conducted by the authors where they have implemented an algorithm for a DTC in order to achieve a tracking system designed for a series of solar panels to maximize its overall efficiency. In this paper, three different switching tables are presented for choosing the best between them for a less fluctuation in torque. This study is justified by reduced cost of implementation compared to other methods that require the use of expensive hardware and complicated control techniques. The tests were carried out under the same conditions with the same equipment of the testbed, to get a good comparative study. Three variants were tested: simple switching table, table of sectors shifted by 30 ° and a table with 12 sectors. The results show an improvement, but a dilemma between the torque ripple and those of the stator flux.

An Implementation of a Twelve Sectors Direct Torque Control Strategy of Induction Machine using DSPACE TMS 320F2812

“…The block diagram of the classical DTC technique stills the same for the 12_DTC [6]. In fact, for both techniques each stator voltage has an effect on the flux and torque.…”

An Experimental Comparison between Conventional and New Direct Torque Control Strategies of Induction Machine using DSPACE TMS 320F2812

“…If the stator flux locus is divided into twelve sectors [8] instead of just six, all six active states will be used per sector and the problem of ambiguity of both flux and torque will be solved. This new stator flux locus is introduced in Fig.5.…”