In recent years the industrial application areas of the high performance AC drives based on Direct Torque Controller (DTC) technique have gradually increased due to its advantages over the field oriented control technique. The main objectives of this paper are to design and implement of a Microcontroller-based Permanent Magnet Synchronous Motor (PMSM) drive. The linear model obtained from application of DTC principle represents the base of the speed control system implemented using a medium performance Microcontroller to solve some problems associated with PMSM. The control algorithms, software programs and required hardware systems are included. A DTC drive system, which is based on a hysteresis bands for both torque and flux controllers. Therefore, there will be minimizing torque ripples and minimize distorted waveforms in currents and fluxes. This thesis introduces a DTC that is expected to improve the dynamic performance. The study will cover the possible ways to overcome disadvantages of the conventional control methods. This DTC system is firstly designed and proved by means of simulations. The complete dynamic model of the drive system and its dynamic performance is investigated using MATLAB-SMULINK software package is given, together with the simulation results in different operating cases. Implementation of an actual drive system based on the suggested DTC including software and hardware, to validate its performance practically is presented. The suggested control strategy guarantees very good dynamic and steady state characteristics with low sampling rate and constant switching frequency. The practical and simulation results show that the use DTC gives good dynamic performance and good tracking response, and they, also indicates the superiority of the suggested system over the conventional control methods. Such type of drives is an absolutely economical and low cost solution by using a single chip low cost microcontroller and efficient for present variable speed drives.
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