A Comparative Study between DPC and DPC-SVM Controllers Using dSPACE (DS1104)

The aim of this paper is to compare two different control structures. The Simple Direct Power Control (DPC) and the Direct Power Control with Space Vector Modulation (DPC- SVM) for two level converter applications. The first strategy (DPC) has been developed to control the instantaneous active and reactive power directly by selecting the optimum switching state of the converter. Applied to the Pulse Width Modulation (PWM) converter its main feature is to improve the total power factor and efficiency, even harmonics components existence. In the second structure, the active and reactive powers are used as (PWM) control vari- ables instead of the three-phase line currents usually used in other techniques. It is shown that DPC-SVM exhibits several properties; good dynamic response, constant switching fre- quency, and in particular it provides a sinusoidal line currents. Simulation and experimental results has shown that both control structures achieve good performances.DOI:http://dx.doi.org/10.11591/ijece.v4i3.607

Relationship between physico-chemical and molecular grain quality parameters for Tunisian durum wheat varieties (triticum durum L.) in different environments

An experimentation using eight Tunisian durum wheat varieties (four landraces and four high yielding ones) was conducted in two different bioclimatic regions (semi-arid and sub-humid) during two growing years. Relationships between agronomic (grain yield), physico-chemical (total protein content, gluten content, gluten index) and molecular parameters (high molecular weight glutenin subunits (HMW-GS), low molecular weight glutenin subunits (LMW-GS) and their ratios) were investigated. The variability of protein content was significant in relation to environment (E), while the gluten index, indicating the gluten strength, was mainly controlled by genotypic factors (G). The quantification in relative percentages of HMW-GS y and x by CE LabChip90 and the estimation of HMW-GSy/HMW-GSx and of HMW-GS/LMW-GS showed that these fractions have varied in relation to E, G and to their interaction (p<0.05). The correlation test showed significant associations between physico-chemical and molecular parameters, whereas these relationships varied significantly in relation to E and G. The Principle Component Analysis (PCA) has distinguished four different quality profiles, where a given variety produced very different qualities in different environments. These results highlight the importance of the evaluation of genotypes under different conditions and suggest that more investigations are requested to optimize the use and the recommendations of varieties

PWM Converters and its Application to the Wind-energy Generation

AbstractThis paper proposes basic concepts of a fixed speed wind turbine (FSWT), as an introduction to a modern wind turbine concept; also, energy extraction from the wind turbine, in order to highlight the utility of the Direct Torque Control (DTC) and Hysteresis Current Control (HCC) in the field of the quality of the electric power. The HCC will be applied to the grid side converter on the way to control the DC link voltage [1]. The Induction Generator (IG) wind turbine connected to the network using back-to-back PWM converters (AC/DC/AC). The theoretical principle of this method is discussed. From the simulation results, it is shown that DTC and HCC display several features, such as a simple algorithm and good dynamic response [2]