Design and Implementation of Direct Torque Control Drive of Three-Phase Induction Motor based on DSP
No Thumbnail Available
Date
2019-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Direct torque control (DTC) technology is a superior, modern and a new type of AC machine
drive control technology developed after vector control technology. In this Thesis, the Direct
Torque Control (DTC) scheme for Induction Motor Drive using Space Vector Modulation
(SVM) technique is studied. DTC provides excellent properties of regulation, even if without
rotational speed feedback. The technology directly controls the instantaneous value of the
electromagnetic torque and stator flux-linkage through the control of stator flux linkage and
electromagnetic torque in the stationary coordinate system and has the advantages of rapid
torque response, simple control structure, and easy digitalization. These quantities are
estimated with only stator voltages, stator currents, and stator resistance.
The induction motor has been modeled and simulated in the stationary d-q reference frame and
its transient and steady-state characteristics are drawn. The MATLAB Simulink consists of an
induction motor mathematical model, a two-level hysteresis comparator for stator flux control,
a three-level hysteresis comparator for torque control, a switching table for voltage vector
selection, stator flux position identifier, a three-phase voltage source inverter (VSI), flux and
torque estimators. The hardware circuit is composed of in addition to the MATLAB Simulink
component it has three-phase Induction machine, TMDSHVMTRPFCKIT with other
necessary equipment. The switching table is employed for selecting the optimum inverter
output voltage vectors so as to attain a fast torque response, low inverter switching frequency,
and low harmonic losses in the code. The simulation of DTC schemes (Conventional DTC)
has been carried out using MATLAB/SIMULINK and the results are discussed. From
estimated speed of simulation result it has good transient and steady state performance with
overshoot 1.531% and with approximated steady state error 0.0002. High Voltage Motor
Control and PFC Development kit (TMDSHVMTRPFCKIT) with TMS320F28035 Control
Card is programmed using code composer studio for hardware implementation of the DTC
scheme and the results are discussed. steady state estimated stator flux module has fluxuation
from the reference with an error of 2.8% maximum ripple.
Description
Keywords
Direct Torque Control, Code Composer Studio, Flux Hysteresis Controller, Torque Hysteresis Controller, Flux and Torque Estimator, Speed Estimator, Stationary Reference Frame, Voltage Source Inverter, Squirrel Cage Induction Motor