Study and Control of Photovoltaic Water Pumping System

Khlifi, Mohamed Arbi The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Solar photovoltaic pumping system is one of most important of renewable energy applications especially in rural areas. Besides, the control strategy for standalone solar pumping system based on induction motor and without DC/DC converter has been widely studied and discussed in the literature. This topology is of great concern due its economic issues, especially when a standard frequency converter (SFCs) with scalar control is used instead of a dedicated PV inverter. This paper proposes an external control module to generate SFCs frequency reference in order to ensure both maximum power point tracking (MPPT). We present method of modeling and control of photovoltaic pumping system based centrifugal pump controlled by new improved incremental conductance in order to optimize the price and operation of pumping system this MPPT algorithm have many advantages like can be eliminate proportional integral controller It is a low cost solution since it requires no additional power equipment. The induction motor driven pump that is powered by a solar array is controlled by the indirect field oriented control (IFOC). The effectiveness of the proposed approach is illustrated by simulations carried out under Matlab Software. The experimental results are compared with simulation results.

Effect of Natural Mediators on the Stability of Trametes trogii Laccase during the Decolourization of Textile Wastewaters

Rim Khlifi-Slama,Tahar Mechichi,Sami Sayadi,Abdelhafidh Dhouib 한국미생물학회 2012 The journal of microbiology Vol.50 No.2

The purpose of the present study was to determine the effect of natural mediators on the stability of the Trametes trogii crude laccase in the process of decolourization of textile effluents. Acetosyringone allowed the highest wastewaters decolourization rate of 25%. At higher concentrations of acetosyringone, the relative activity of laccase decreased approximately by between 38% and 88% after 5 days of incubation. T. trogii laccase was strongly inactivated at 3mM syringaldehyde, after 3 days of incubation. However,laccase activity is more stable in the presence of the vanillin and m-coumarate. The T. trogii growth on solid effluentbased-medium was examined and evaluated by measuring the colony diameter in cm. T. trogii was completely inhibited on 100:0 and 80:20 effluent:water solid medium, however,colony diameter reached 5 cm on 60:40 effluent:water solid medium after 13–14 days incubation. When the textile effluent was pre-treated with laccase and laccase-acetosyringone system, the colony diameter of 2 cm of T. trogii on 80:20effluent:water solid medium was reached after 14 and 10days of incubation respectively.

Study and Control of Photovoltaic Water Pumping System

Mohamed Arbi Khlifi 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Solar photovoltaic pumping system is one of most important of renewable energy applications especially in rural areas. Besides, the control strategy for standalone solar pumping system based on induction motor and without DC/DC converter has been widely studied and discussed in the literature. This topology is of great concern due its economic issues, especially when a standard frequency converter (SFCs) with scalar control is used instead of a dedicated PV inverter. This paper proposes an external control module to generate SFCs frequency reference in order to ensure both maximum power point tracking (MPPT). We present method of modeling and control of photovoltaic pumping system based centrifugal pump controlled by new improved incremental conductance in order to optimize the price and operation of pumping system this MPPT algorithm have many advantages like can be eliminate proportional integral controller It is a low cost solution since it requires no additional power equipment. The induction motor driven pump that is powered by a solar array is controlled by the indirect field oriented control (IFOC). The effectiveness of the proposed approach is illustrated by simulations carried out under Matlab Software. The experimental results are compared with simulation results.

DIRICHLET EIGENVALUE PROBLEMS UNDER MUSIELAK-ORLICZ GROWTH

Benyaiche, Allami,Khlifi, Ismail Korean Mathematical Society 2022 대한수학회지 Vol.59 No.6

This paper studies the eigenvalues of the G(·)-Laplacian Dirichlet problem $$\{-div\;\(\frac{g(x,\;{\mid}{\nabla}u{\mid})}{{\mid}{\nabla}u{\mid}}{\nabla}u\)={\lambda}\;\(\frac{g(x,{\mid}u{\mid})}{{\mid}u{\mid}}u\)\;in\;{\Omega}, \\u\;=\;0\;on\;{\partial}{\Omega},$$ where Ω is a bounded domain in ℝ^N and g is the density of a generalized Φ-function G(·). Using the Lusternik-Schnirelmann principle, we show the existence of a nondecreasing sequence of nonnegative eigenvalues.

Performance Limits of Three-Phase Self-Excited Induction Generator (SEIG) as a Stand Alone DER

Slimene, Marwa Ben,Khlifi, Mohamed Arbi The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper present a unified method of steady state performance analysis and limits characteristics of an autonomous three-phase self-excited induction generator (SEIG) driven by a wind turbine under different types of loads and speeds. The proposed method is based on a new mathematical function to solve for the real and imaginary components of the complex equation of the mathematical model. Performances limits, regulation and characteristics of different configurations will be thoroughly examined and compared. The proposed system will be modeled and simulated and the performance limits characteristics will be compared with variable speed and variable capacity.

Apple Cider Vinegar Attenuates Oxidative Stress and Reduces the Risk of Obesity in High-Fat-Fed Male Wistar Rats

Ben Hmad Halima,Gara Sonia,Khlifi Sarra,Ben Jemaa Houda,Ben Slama Fethi,Aouidet Abdallah 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.1

Metabolic syndrome is a serious consequence of obesity characterized by increased cardiovascular risk factors such as hypertension, dyslipidemia, and glucose intolerance. While diets enriched with natural antioxidants showed beneficial effects on oxidative stress, blood pressure, and serum lipid composition, diet supplementation with synthetic antioxidants showed contradictive results. Thus, we tested, in this study, whether a daily dosage of Apple Cider Vinegar (ACV) would affect cardiovascular risk factor associated with obesity in high-fat diet (HFD)-induced hyperlipidemic Wistar rats. Obese rats showed increased serum total cholesterol, triglyceride, low-density lipoprotein-cholesterol (LDL-C), very low density lipoprotein (VLDL) and atherogenic index after 6 and 9 weeks of being fed an HFD. Importantly, ACV ameliorated all of these parameters significantly. Oxidative stress already developed after 6 weeks of HFD and was significantly reduced by daily doses of ACV. Oral administration of ACV normalized various biochemical and metabolic changes since it exhibited a very significant (P < .001) reduction in malondialdehyde levels, whereas an increase in thiol group concentrations and antioxidant status (superoxide dismutase [SOD], glutathione peroxidase [GPx], and catalase [CAT] activities and vitamin E concentrations). In addition, a modulation in trace element levels was observed when compared with HFD groups. These findings suggested that HFD alters the oxidant–antioxidant balance, as evidenced by a reduction in the antioxidant enzyme activities and vitamin E level, and enhanced lipid peroxidation. ACV can be beneficial for the suppression of obesity-induced oxidative stress in HFD rats through the modulating antioxidant defense system and reduces the risk of obesity-associated diseases by preventing the atherogenic risk.

Modeling of a Dual Stator Induction Generator with and Without Cross Magnetic Saturation

Marwa Ben Slimene,Mohamed Arbi Khlifi,Mouldi Ben Fredj,Habib Rehaoulia 한국자기학회 2015 Journal of Magnetics Vol.20 No.3

This paper discusses general methods of modelling magnetic saturation in steady-state, two-axis (d & q) frame models of dual stator induction generators (DSIG). In particular, the important role of the magnetic coupling between the d-q axes (cross-magnetizing phenomenon) is demonstrated, with and without cross-saturation. For that purpose, two distinct models of DSIGs, with and without cross-saturation, are specified. These two models are verified by an application that is sensitive to the presence of cross-saturation, to prove the validity of these final methods and the equivalence between all developed models. Advantages of some of the models over the existing ones and their applicability are discussed. In addition, an alternative is given to evaluate all saturation factors (static and dynamic) by just calculating the static magnetizing inductance which is simply the magnitude of the ratio of the magnetizing flux to the current. The comparison between the simulation results of the proposed model with experimental results gives a good correspondence, especially at startup.

Performance Limits of Three-Phase Self-Excited Induction Generator (SEIG) as a Stand Alone DER

Marwa Ben Slimene,Mohamed Arbi Khlifi 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper present a unified method of steady state performance analysis and limits characteristics of an autonomous three-phase self-excited induction generator (SEIG) driven by a wind turbine under different types of loads and speeds. The proposed method is based on a new mathematical function to solve for the real and imaginary components of the complex equation of the mathematical model. Performances limits, regulation and characteristics of different configurations will be thoroughly examined and compared. The proposed system will be modeled and simulated and the performance limits characteristics will be compared with variable speed and variable capacity.

Estimation of Hydropower Synchronous Generator Parameters Through Field Simulations of Modified Standard Tests

Marwa Ben Slimene,Abdelaziz Salah Saidi,Mohamed Arbi Khlifi 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

The present paper deals with a simple but suffi ciently accurate method for constant parameter identifi cation of synchronous machine standard circuit model. The method is mainly based on classical tests at the line frequency as for induction machines. The proposed identifi cation process is organized in a sequence beginning by a correct evaluation of the fi eld to armature turns ratio, whereby the rest of invariant parameters are estimated from standstill tests. Simulations and experiments of synchronous machine transients, in normal and faulty operations, were carried out to prove the validity of the method.