Elmostafa Elwarraki

Combined Vector Control and Direct Torque Control an experimental review and evaluation

This work presents an experimental evaluation based on DSP of Combined Vector Control and Direct Torque Control strategy. This strategy permits to control torque and flux by controlling the stator current and by using a switching Table instead of PI controllers. This Control combine the characteristics of both Direct Torque Control and Vector Control to provide high dynamic for torque response. The experimental implementation in real-time of this control has been successfuly made with 1KW induction motor and using a dSPACE system equipped with Digital Signal Processor TMS320F240 DSP. In order to evaluate this strategy, this paper proposes an experimental comparaison with the vector control. Results are presented to show the advantages and the drawback of this Strategy.

Robustness of fuzzy controller based adaptation mechanism for MRAS sensorless IM drives

This paper presents a technique of adaptation mechanism based on a fuzzy controller for speed estimation using model reference adaptive system (MRAS) approach in a direct filed oriented control. The estimated speed is used as feedback for control system. The aim of this mechanism is to improve the control and sensorless speed estimation of induction motor in high, low speed and also under a load torque vibrations. The major contributions of this mechanism are verified by simulation under Matlab/Simulink. Simulation results are presented in order to prove the performance of this mechanism.

Pspice behavior and thermal modeling of the PIN Diode: A circuit approach

The modeling of the semiconductor devices and the need for simulation became currently very essential in power electronics. It permits at the same time to reduce the time and the development costs of the devices, as it makes thereafter to increase the reliability of the designed circuits. By the present article, we could prove the possibility to develop behavioral and electrothermal circuit models of the bipolar devices. These models, also simple, regarding the compromise precision-complexity and compatible with the electric circuits softwares simulator.

Intelligent Control for Torque Ripple Minimization in Combined Vector and Direct Controls for High Performance of IM Drive

In Conventional Combined Vector and Direct Controls (VC-DTC) of induction motor, stator current is very rich in harmonic components. It leads to high torque ripple of induction motor in high and low speed region. To solve this problem, a control method based on the concept of fuzzy logic approach is used. The control scheme proposed uses stator current error as variable. Through the fuzzy logic controller rules, the choice of voltage space vector is optimized and then torque and speed are controlled successfully with a less ripple level in torque response, which improve the systems performance. Simulation results trough MATLAB/SIMULINK® software gave results that justify the claims.

Behavioural and Electrothermal Modelling of the IGBT for Circuits Simulation

The semiconductor devices modelling became today an indispensable tool in the electronic and power electronic fields. Recently several devices models are presented, resulting from semiconductors physics and which are intended only for the design and to the improvement of device performances themselves. On the other hand, as users one, we are interested in their electrical and thermal behaviour. Indeed, the insertion of these devices in a circuit environment necessitates enough often to find models from passive elements and that reproduce the same behaviour. It appears therefore necessary to adapt the existing models or to develop new behavioural devices models to solve evoked problems in the circuits design. In this way, our paper is interested in the modelling of the IGBT device.