M. BENGUESMIA Hani

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Abstract
Understanding flashover voltage and leakage current is crucial for evaluating and ensuring the performance, reliability, and safety of high-voltage insulators in electrical networks. Investigating the flashover process and leakage current is significant because it helps to understand the behavior of insulators under different conditions, such as desert pollution. The objective of our study is to create a circular model that accurately simulates the real functioning of a 1512 L high-voltage insulator.
This particular insulator is widely utilized by the algerian power and gas company (SONELGAZ), contributing significantly to the comprehension of its operational principles. In our current work, we aim to investigate the effect of conductivity and the distribution of discontinuous contamination on insulator behavior and its response within an intentionally contaminated experimental model. Additionally, we aim to incorporate previous insights regarding the severity of contamination at specific locations. Our ongoing research relies on observations and various measurements obtained from flashover voltages and leakage currents. Through this model, researchers can comprehensively evaluate insulator performance under diverse conditions,facilitating a deeper understanding of their behavior. The analysis of the results obtained from numerous tests conducted in the high-voltage laboratory of the University of Biskra, Algeria, forms the basis of our study.

Ce polycopié (TP Réseaux Electriques) de travaux pratiques est destiné aux étudiants de troisième année licence en électrotechnique du système LMD Sciences et Technologie. Son objectif est mettre à leur disposition un document de travail, leur permettant de s’imprégner
de la théorie exposée en cours et de faciliter sa mise en pratique pendant les manipulations expérimentales.
Dans le système LMD, les activités expérimentales et donc les mesures, occupent une place importante. Ces travaux pratiques est de compléter les notions qui sont vues dans les cours et travaux dirigés de réseaux électriques de troisième année licence en électrotechnique.
Aussi, est-il essentiel, non seulement d’acquérir les savoir-faire indispensables à une bonne utilisation du matériel et des différents appareils de mesures employés, mais également d’aboutir à une bonne compréhension des méthodes mises en œuvre. C’est la raison pour laquelle la préparation des travaux pratiques doit être considérée avec sérieux et attention par les étudiants, afin d’en tirer le maximum de profit sans détériorer le matériel mis à leur disposition.

Ce polycopié a été conçu dans le but d’être considéré comme étant un support pédagogique. Ce cours "Production centralisée et décentralisée", s'adresse aux étudiants en Master professionnelle, filière électrotechnique, en particulier les étudiants en Master 1 option Réseaux Electriques. Ce polycopié vise présenter l’évolution fondamentale des systèmes énergétiques induite par la transition énergétique qui est une décentralisation de ces systèmes. Ce support est constitué d'un plan de cours qui a pour but de donner les directives pédagogiques qui facilitent la compréhension et l’assimilation des leçons de " Production centralisée et décentralisée". L’ensemble des parties présentées dans ce document ont été effectuées au sein du Laboratoire de Génie Electrique (LGE) de l’Université Mohamed Boudiaf de M'sila.

This book examines two potent approaches to predictive modeling and optimization: Artificial Neural Networks (ANN) with an emphasis on Feedforward Neural Networks (FNN) and Response Surface Methodology (RSM) with Central Composite Design (CCD).

Abstract. An accurate personal identification system helps control access to secure information and data. Biometric technology mainly focuses on
the physiological or behavioural characteristics of the human body. This paper investigates the Finger Knuckle Print (FKP) biometric device based
on the feature extraction technique. This FKP authentication method includes all the essential processes, such as preprocessing, feature extraction
and classification. The features of the FKP application are investigated. Finally, this paper proposes the selection of the best feature extraction
based on FKP recognition efficiency. The primary purpose of this paper is to use the Local Binary Patterns (LBP), Binarized Statistical Image
Features (BSIF), and Gabor filters and define which helps to increase the False Acceptability Rate (FAR) and Genuine Acceptability Rate (GAR).
This latest FKP selection shows better results as this concept shows promising results in recognizing a person's fingerknuckle print.

Abstract. All the studies and articles on the DTC control system talk about its shortcomings and the problems resulting from the use of hysteresis
controllers. It results in strong ripples in torque, steady flow and constant current. Moreover, it is difficult to adjust the sensitivity to parametric
variables due to the use of PI controllers due to the complexities of the system. To overcome these drawbacks and through this article, DTC control
is designed on Double Star Induction Motor (DSIM), and through experiments it showed us some problems caused by hysteresis. Advantages can
also be used of artificial intelligence techniques like fuzzy logic, fuzzy control is a way to control a system without needing to know its mathematical
model of the system. To this end, It is through the advantages of fuzzy logic that it has been applied in this article to the application of DTC control,
which is called Fuzzy Direct Torque Control (FDTC). Where we have replaced hysteresis controllers and switch tables with fuzzy logic switch
controllers. We also simulated it by MATLAB/SIMULINK and compared the results obtained between a conventional DTC and a DTC using fuzzy
logic and it is shown that the proposed FDTC method can significantly reduce torque ripples and is suitable for different motors under operating
conditions.

A solar air heater is a device that gathers solar radiation and converts it into heat. The core principle involves air moving through a solar collector, where sunlight naturally increases the air temperature within the collector. The benefit of this technology lies in its affordability and simplicity. The implementation of a solar air heater (SAH) test bench holds significant promise in addressing both global change and sustainable development objectives. The primary goal of this study is to examine the aerodynamic configuration of a novel solar air heater test bench accessible at the Laboratory of Electro-Mechanic Systems (LASEM). This study was carried out using the standard k-ω turbulence model with the use of the ANSYS Fluent 17.0 software. The results indicate that the velocity at the inlet directly influences the velocity fields, temperature, static pressure, and characteristics of turbulence. Furthermore, the numerical findings confirmed that the temperature and velocity profiles in the second channel are in good concordance with the experimental findings in the case of a fan, placed alongside the insulation, operating in a delivery mode. Based on these results, the computational approach is validated. When comparingforced convection to natural convection under identical conditions, there was a notable increase in the energy efficiency, with forced convection showing a significant improvement of approximately 31.8%. Indeed, the range of temperatures reached with the proposed design, is highly beneficial for both industrial and household applications.

Abstract. The aim of this work is to estimate the flashover voltage of a high-voltage insulator that has been deliberately polluted using fuzzy logic
(FL). Initially, experimental experiments on a high-voltage insulator were used to collect a data set that was then used to implement the idea of
artificial intelligence. These studies were conducted using varying degrees of fake pollution, namely saline distilled water. Each pollution level
indicated the quantity of artificial pollution, measured in millilitres, in each section of the insulator. The collecting database provides flashover voltage
measurements associated with varying levels of artificial pollution in each insulator zone and its conductivity. Furthermore, we have used fuzzy logic
(FL) to forecast the flashover voltage of the high-voltage insulator and assess the insulating condition of simulated pollution. The suggested
prediction model, which is based on Federated Learning (FL), is implemented using MATLAB's graphical user interface. Ultimately, a comparison
was conducted between the outcomes achieved by FL and real-world ones. The database used in this comparison differs from that used in concepts
based on programming language implementation taken from previous literature. The findings demonstrate the superior effectiveness of the FL
approach in predicting the flashover voltage of high-voltage insulators when compared to data acquired from practical testing.

Cet ouvrage a été conçu dans le but d’être considéré comme étant un livre pédagogique,s'adresse aux étudiants de Master, filière électrotechnique.
Ce livre est constitué d'un plan qui a pour objectif de donner les directives pédagogiques qui facilitent la compréhension et l’assimilation des leçons de "Réseaux Electriques".
Enfin, j’espère bien que ce présent ouvrage donne intérêt aux lecteurs, et je serais très heureux de recevoir avec reconnaissance leurs remarques, leurs questions, critiques et suggestions

The chimney junction of solar chimney power plant was the main element coupled the solar collector to the chimney. It presents an important impact on the SCPP design, which is change the air-flow direction. The numerical code ANSYS Fluent was used in this study to investigate how the chimney Junction radius affected the local air-flow characteristics and the turbine site. Using test results from an experimental prototype constructed in Sfax, Tunisia, the numerical method was validated and verified. For four set-ups with various chimney connection radii, thermodynamic variables such as distributions of the total pressure, static temperature, static pressure, and magnitude velocity were examined. Also, the influence of these parameters on the air turbulence was analyzed through the transition zone. The results showed that the local air-flow characteristics and therefore, the SCPP efficiency were significantly impacted by changes in junction radius. Besides, the maximum velocity inside the chimney was varied and changes its location when the junction radius changed. These facts affect directly the overall turbine expenditure, which represented in terms of structure and power capacity.

The paper proposes an adaptive neuro-fuzzy inference system called ANFIS for predicting the flashover voltage of external
insulators. High voltage insulators were the subject of actual testing, which produced a database for the application of
artificial intelligence ideas. The experiments were conducted using different concentrations of synthetic pollution (distilled
brine), with each concentration denoting the amount of contamination per milliliter of area. The database offered flashover
voltage values for various pollution levels and electrical conductivity levels in each isolation zone. Adaptive neuro-fuzzy
inference employed a hybrid learning algorithm to determine suitable membership functions, minimizing the root mean
square error as the performance criterion. The primary parameters affecting flashover voltage were identified: applied high
voltage, conductivity of the artificial impurity, and amount of impurity in the insulation. For both training and test data,
precise predictions were obtained by using membership functions in the shape of a triangle with three fuzzy sets. During
testing, the technique demonstrated a low mean absolute percentage error (0.027011) and a high coefficient of determination
(0.999997049). Comparison with practical tests yielded a root mean square error of 0.0128623, confirming the effectiveness
of the Adaptive Neuro-Fuzzy Inference System in estimating the critical flashover voltage for newly designed insulators
under different operating conditions.

ABSTRACT
This paper is intended to check the thermal convection flow during a new solar air heater (SAH) test bench,
which is conducted in the LASEM laboratory. In fact, the applied system includes a two-passage heater solar
air separated by an absorber. On the other hand, a glass piece is connected to the box prototype via a pipe. The
study was conducted using the Navier-Stokes equations associated with the k–ω turbulence model through the
use of Ansys 17.0 software. Based on our experimental results generated in a two-passage solar air heater
connected to the box prototype, the computational approach and the simulation results were validated.

Abstract

In this study, we examine an approach to control the reactive powers of a doubly fed induction generator (DFIG) through optimal feedback linearization control (FLC). To achieve this we utilize the artificial bee colony (ABC) based controller. Our aim is to address the limitations of tuning methods by proposing an algorithm that generates gains, for the PI controller. This will ultimately enhance the performance of FLC DFIG response. We validate our control strategy using MATLAB SIMULINK with a 1.5 MW DFIG wind turbine. The simulation results demonstrate that the optimal feedback linearization control significantly improves performance compared to feedback linearization control as evidenced by reduced overshoot steady state error and settling time.

Abstract

The solid oxide fuel cell (SOFC) is broadly used for distributed and clean power generation. The main problem related to SOFC lies in the difficulties to control the output voltage of the SOFC due to the strong nonlinearity, the rapid changes of the load and the limited fuel flow. The objective of the control of the SOFC system is to maintain the output voltage at a constant level and the fuel utilization rate in a safety interval. In this context, a multiple-input multiple-output (MIMO) discrete-time Takagi-Sugeno (TS) fuzzy dynamic model with feed forward input is used in this study to describe the dynamic properties of the nonlinear voltage and the fuel utilization rate in a tubular SOFC system. This obtained fuzzy model will be used for the application of constrained fuzzy model predictive control. The simulation results are provided to show the accuracy and the effectiveness of the proposed strategy.

Abstract

Accelerometers are commonly associated with motion and position sensing in various applications, but their utilization extends beyond these traditional domains. In the context of solar photovoltaic (PV) installations, accelerometers offer a unique opportunity to enhance system efficiency and reliability. This abstract delves into the innovative integration of accelerometers in solar energy systems, with a focus on their ability to optimize energy generation, tracking, and monitoring. By providing real-time data on tilt, orientation, and vibrations, accelerometers enable precise solar panel positioning, leading to improved energy capture. Moreover, they play a pivotal role in predictive maintenance, helping to detect and mitigate potential issues before they impact system performance. This abstract explores the multifaceted benefits of harnessing accelerometers in solar PV installations and highlights their contribution to sustainable and resilient energy solutions.

Abstract

The main insulation layer is the most important layer of the high-voltage cable, and the quality of this material directly affects the life of the cable. It is also known that Heterogeneous cavities associated partial discharges in the insulation can affect the service life of cables. In this paper, we use the COMSOL Multiphysics software, which is based on the finite element method in AC/DC, 2D electrostatic. Heterogeneous cavities, such as bowtie water trees, vented cavities, and air void cavities, are easily damaging to XLPE power cables. This paper studies the electrical constraints within an XLPE-insulated cable containing micro-cavities. Due to the possibility of partial discharge (PD), it is crucial to be aware of the existence of heterogeneous cavities in insulating materials before using them as cable insulation. This study examines the impact of having such diverse voids in the insulation of high-voltage cables. Additionally, using the COMSOL tool, the impact of altering the cavity's position and size on the PD behavior under various operating circumstances was examined. The obtained results are in good agreement.
Keywords: Heterogeneous cavities, Electric field and potential, cables.

Abstract

The device is implemented using the Proteus simulation environment. The design has been successfully tested and validated, and the device is shown to be accurate and reliable. The device can be used in a number of applications, such as monitoring solar irradiation in stand-alone or grid-connected photovoltaic power plants. : In electric transmission lines,, the insulators must be able to endure transient over voltages caused by lightning, operational shocks, and sandstorms on the insulating surface, as well as electrical strains during typical operating circumstances (over a broad range). This investigation examines the behavior of pollution on the surface of a high-voltage cap and pin insulator (175CTV) used by Algeria's National Electricity and Gas Company. It is done by numerical modeling. The methodology used and the findings in this paper offer up a number of avenues for modeling and numerical simulation of physical processes impacting high voltage transport and distribution line insulators under humid circumstances (rain, dew, etc.). The 2D/3D results are compared to demonstrate that the numerical simulation always provides an accurate sense of variance.

Abstract

The main goal of the proposed study of the active parallel filter to improve the quality of electrical energy. Based on network currents and voltages measurements respectively. In addition to DC voltage. Through the method of identifying harmonic currents such as the instantaneous power method for extracting the disturbing current, on the other hand, the filter consists of the study of a two-level voltage inverter controlled by a regulator at hysteresis a detailed comparison is made with criteria the before and after filtering to determine stability the systems. The simulation results obtained showed good performance for the proposed control.

Abstract

One of the world's oldest renewable energy sources is solar energy, which may be easily harnessed to lessen dependency on energy derived from hydrocarbons and is readily available. Data on solar radiation are crucial for the planning, development, and operation of energy and renewable energy systems. Numerous considerations had a role in the decision to locate the solar power plant in Ain El-Melh. First and foremost, the site's accessibility was essential since Ain El-Melh is near transportation hubs, making it simple to relocate workers and construction equipment. Solar irradiance is necessary to calculate several aspects of system performance connected to the sun, such as the size and efficiency of renewable energy systems. The objective of this study is to use real meteorological data to develop an artificial neural network-based forecast model for the Ain El-Melh region. The results allowed for the selection of this approach because of its advantages that were specific to the problem at hand.

Abstract

We propose a new low-cost device to measure total solar radiation using a reference photovoltaic cell. This device is based on the proportional relation between the solar radiation and the short-circuit current of the photovoltaic cell. The device consists of a circuit that measures the voltage and current of the photovoltaic cell by a shunt resistor, and anADC that converts analog data into digital. The Arduino UNO platform is used to process data and display incident solar radiation on the reference cell. This device can be used to monitor solar radiation in an stand-alone or grid-connected photovoltaic installation, and also to evaluate the performance of solar panels.

Abstract

Electrostatic forces and persistent partial arcs under HVAC stress are the main contributors to insulator pollution. Understanding this behavior is essential because contaminated insulator flashover can cause extensive, protracted power outages. Pollution flashover is a crucial factor to take into account while building transmission lines and conversion facilities, especially those used in AC systems. In order to study the flashover mechanism of polluted insulators under AC voltage, a new model uses a two-dimensional (2D) numerical model based on the finite element method is proposed to examine how the potential and electric field are distributed throughout the model's leaking distance. The COMSOL Multiphysics simulation results obtained show that the suggested approach is successful and yields positive outcomes.

Abstract

Insulators are important components in electrical transmission lines since they prevent the discharge between the towersand the ground. In this paper, a numerical simulation was carried out to study the performance enhancement of a1512L insulatorstrings. The software "COMSOL Multiphysics" has been used to present the local characteristics in different applied voltage and conductivities pollution. This work demonstrates how to use the Electrostatic interface to calculate the surface electric field of a typical high-voltage insulator. This study encompasses the modeling and simulation of 3D insulator and the behavior of the potential andelectric field along its length under AC voltage. This helps to identify the problems that may occur along its surface. Use of thisknowledge will assist a better understanding and the design of insulators (cap and pin) installations of the electrical networks.

Abstract

Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. Power systems are significantly hampered by the flashovers phenomenon, which can cause outages and raise safety issues. Prediction accuracy is crucial for preserving grid reliability. In this paper a tailored model for the prediction of the flashover voltage of the 1512L insulator was made using RSM central composite design and compared to a network created using a feed forward artificial neural network. Both the models would take the conductivity and the level of pollution as an input. By making two networks in ANN one with a small portion of the data and another with the full set of data a comparison between the two methods is made to see the advantages and disadvantages of each method compared to the other.

Abstract

This work presents the design and implementation of a low-cost device for measuring global solar irradiation based on a reference photovoltaic cell. The device operates by measuring the short-circuit current of the photovoltaic cell, which is proportional to the incident solar irradiation. The short-circuit current is measured using a shunt resistor, and the resulting voltage across the shunt resistor is scaled using an operational amplifier circuit. The scaled voltage is then fed into an analog-to-digital converter (ADC) for further processing. The Arduino Uno platform is used to process the ADC data and display the measured solar irradiation in real time.
The device is implemented using the Proteus simulation environment. The design has been successfully tested and validated, and the device is shown to be accurate and reliable. The device can be used in a number of applications, such as monitoring solar irradiation in stand-alone or grid-connected photovoltaic power plants.

Abstract

This study introduces a deadbeat control method designed specifically for a single-phase inverter used in uninterruptible power supply (UPS) applications. The proposed control method necessitates the measurement of both capacitor current and output voltage in order to maintain sinusoidal output voltage and achieve high dynamic performance, even in the presence of load variations. The deadbeat controller aims to eliminate discrepancies between the output voltage and voltage reference, there by optimising the controller's performance without requiring additional current sensors. Furthermore, the deadbeat controller aims to counteract load voltage distortion and restore the system's state in the event of an external closed-loop disturbance. In order to address this drawback, we suggest employing a Luenberger observer to estimate the current of the capacitor.

Abstract
Electrostatic forces and persistent partial arcs under HVAC stress are the main contributors to
insulator pollution. Understanding this behavior is essential because contaminated insulator flashover
can cause extensive, protracted power outages. Pollution flashover is a crucial factor to take into
account while building transmission lines and conversion facilities, especially those used in AC
systems.This work uses a two-dimensional (2D) numerical model based on the finite element method
to examine how the potential and electric field are distributed throughout the model's leaking distance.
The COMSOL Multiphysics simulation results obtained show that the suggested approach is
successful and yields positive outcomes

Abstract
Heterogeneous cavities, such as bowtie water trees, vented cavities, and air void cavities, are easily
damaging to XLPE power cables. This paper studies the electrical constraints within an XLPEinsulated
cable containing micro-cavities. Due to the possibility of partial discharge (PD), it is crucial
to be aware of the existence of heterogeneous cavities in insulating materials before using them as
cable insulation. This study examines the impact of having such diverse voids in the insulation of
high-voltage cables. Additionally, using the COMSOL tool, the impact of altering the cavity's position
and size on the PD behavior under various operating circumstances was examined. The obtained
results are in good agreement.

Abstract
One of the most important power quality problems, current harmonics has generated a lot of study
attention. The greatest way to reduce harmonic contamination is to use a shunt active power filter
(SAPF), however, its efficiency is entirely reliant on how quickly and precisely its control algorithms
can work. This study investigates the functioning of a four-wire shunt active power filter (SAPF)
under unbalanced load situations using a simulation of a three-phase four-wire shunt active power
filter (SAPF) decreased current measurement control technique caused by nonlinear loads. The
suggested method for correcting the load's reactive power and harmonic currents is effective,
according to simulation results produced by Matlab/Simulink.

ABSTRACT
Solar energy is widely used source of renewable energy in Algeria. sOur work aims to produce a device for
measuring global solar radiation based on a reference photovoltaic cell and an Arduino Uno board to set up a
system that can provide a precise, reliable and less expensive method for measuring the quantity solar radiation
reaching the Earth's surface. The principle of this device based on the proportional relationship between solar
radiation and short circuit current, the latter is measured by a shunt resistor and a component based on an
operational amplifier scales the potential difference across this resistance, which is then brought to possible
processing by an analog-to-digital converter. The processing is carried out on an Arduino Uno platform, which
also displays in real time the solar radiation received by the surface of the reference cell. The component is an
inexpensive device that can be used for a variety of tasks, such as measuring solar radiation in stand-alone or
grid-connected photovoltaic installations. The Proteus environment was chosen to implement the device and
was successfully tested.

ABSTRACT
The spectrum irradiance must be measured because different sunlight wavelengths (or colors) are absorbed in
various regions of our atmosphere. Calculating different sun-related system performance, such as the size and
performance of renewable energy systems, requires knowledge on solar irradiance. The goal of this work is to
create a forecast model based on artificial neural networks in the M'sila area using actual meteorological data.
The outcomes made it possible to choose this strategy due to its benefits that were tailored to the issue at hand.

Abstract
Due to its multiple advantages in industrial and grid-connected applications, Multi-Level Inverters (MLIs) have increased in popularity in recent years. To improve the efficiency of a grid-connected PV system's integrated multi-level inverter fractional order PI (FOPI) controllers are used to describe the control process. The control system is made up of three control loops based on FOPI controllers: one for controlling the intermediate circuit voltage (Vdc) and the other two for controlling the direct and quadratic currents (Id, Iq) supplied by the multilevel inverter. The proposed controller parameters (Kp, KI, λ)must be selected in order to increase the efficiency of the multi-level inverter while decreasing the total harmonic distortion (THD) of the output current of the inverter as well as voltage. For this we used three meta-heuristic algorithms (PSO, ABC, GWO). The performance of the three controllers PSO-FOPI, ABC-FOPI and GWO-FOPI controller is compared. The findings showed that GWO-FOPI performs better than the other PSO-FOPI and ABC-FOPI in accuracy and total harmonic distortion THD term. The simulation will be conducted using Matlab/Simulink.

Abstract. These Applications of fractional calculus are becoming more and more effective, adaptable, and have produced positive outcomes in a variety of engineering and scientific domains. In this paper, a fuzzy fractional-order PI-based control approach for grid-connected photovoltaic (PV) systems is presented.
The various advantages of multi-level inverters (MLIs) in industrial and grid-connected applications have resulted to their increasing application in recent years.
A five-level neutral point (NPC) inverter is used to integrate PV electricity into the electrical grid with minimal harmonic distortions and highest power capacity.
The output voltage of the inverter must be maintained in order to connect to a grid, even though that the photovoltaic output voltage varies considerably with solar radiation. To achieve this, three fuzzy fractional order PI (FFOPI) controllers were used to control the inverter output voltage (Vdc), direct current (Id), and quadratic current (Iq) around a reference values. A further comparison is made with the fuzzy PI (FPI). According to research, the FFOPI controller outperforms the FPI controller in terms of performance.

Abstract In this paper, a deadbeat control technique for single-phase inverters used in UPS applications is presented. For the suggested
control approach to maintain sinusoidal output voltage for high dynamic performance even with load fluctuations, measurements of capacitor
current and output voltage are necessary. By reducing the error between the output voltage and the voltage reference without adding more
current sensors, the deadbeat controller improves the performance of the proposed controller. It also reduces load voltage distortion and
restores the system state in the event of an external shutdown-loop road interference. We suggest a capacitor current estimation based on the
Luenberger observer to address this flaw. PROCESSOR-IN-THE-LOOP The "P.I.L" test method, which can be thought of as an expensive
system, enables us to create and evaluate controllers by running built-in C code on the DSP scheduled for the controller during simulated
PSIM power phase control. To address this drawback, we propose a capacitor current estimation based on the Luenberger observer.

Abstract

Solar chimney power plants are passive thermal systems that use the greenhouse effect to produce electricity from solar radiation (SR). The performance of these devices varies from one climate to another. Indeed, the building site of the SCPP is a particular parameter for its total effectiveness. The aim of this work was to present an experimental investigation of a solar chimney prototype under the climatic conditions of Sfax, Tunisia. In fact, Sfax is characterized by its arid and sunny climate. The impact of the climatic conditions of Sfax city on the aero-thermal characteristics of the considered prototype is carried out. Particularly, the variations of the fluid temperature and velocity are carried out under different times. The present outcomes show that the solar chimney power plant is an applicable device in the Tunisian region of Sfax.

ABSTRACT
This article introduces a grid-connected photovoltaic (PV) source combined with a multi-level inverter. A converter five-level neutral point (NPC) can be used to integrate the PV power into the power grid with minimum harmonic distortions and high power capacity. If the output voltage of the PV generator varies significantly with solar radiation, the output voltage of the ripple must be fixed. For this reason, a regulation loop was used. In this study, we used a classical PI regulator. It is difficult to determine the PI controller transaction values, so Genetic Algorithm was used to optimize the PI controller parameters. The Matlab/Simulink simulation results show the better performance and efficiency of the PI controller
optimized by the GA, in comparison to the stand-alone PI controller, regarding stability and accuracy, and the reduction of Total Harmonic Distortions (THD) of the current injected into the grid for any difference in solar radiation.

Abstract
The knowledge of the behavior of both the electric potential and electric field is one of the main factors
needed when designing an insulator. Using AutoCAD software a 2D cap and pin 1512L insulator model was
created in the clean state and under pollution from one to five insulators separately making a chain of insulators
for a total of 10 models. Later they are imported to COMSOL Multiphysics 5.6 software, simulations of the
1512L insulator were made to see the effect the pollution has and the differences that occur on the distribution
with the addition of more insulators in the chain. The potential distribution starts to develop a pattern after a
certain number of insulators in the chain while the pollution induces high value spikes in the field
distribution. Finite-element-analysis for numerical simulation of the pollution effect in outdoor insulators: a
review and a novel method.

Abstract

ABstract: Brevet

Abstract
The main insulation layer is the most important layer of the high-voltage cable, and the quality of this
material directly affects the life of the cable. It is also known that contamination, porosity and associated partial
discharges in the insulation can affect the service life of cables. In this paper, we use the COMSOL Multiphysics
software, which is based on the finite element method in AC/DC, 2D electrostatic. Our study shows the effect
of heterogeneous cavities on the functioning of electrical cables. This work contains the study of electric field
distribution and potential of a model of high voltage cable; we took into account the absence and the presence
of heterogeneous cavities. The study was conducted using numerical results with mathematical validation. The
obtained results are considered satisfactory, favorable and very promising.

ABSTRACT This paper presents a dead-beat control algorithm for Uninterruptible Power Supply (UPS) applications of single-phase inverters. The proposed control method requires the measurement of capacitor current and output voltage in order to keep the output voltage sinusoidal ensuring high dynamic performance even under load changes. The dead-beat controller optimizes the behavior of the system by eliminating the error between the output and the reference voltage without increasing the number of current sensors, which are costly, and eliminates load voltage distortions and restores the system state in the event of external shutdown-loop road interference. In this paper, we propose a capacitor current estimation based on theLuenberger observer. Processor-In-the-Loop (PIL) is a test method that allows us to create and evaluate controllers by running built-in C code on the DSP scheduled for the controller during simulated PSIM power phase control. It can be seen that the simulation results match the PIL test results, which proves the validity of the proposed controller.

Abstract

Distributed photovoltaic units are frequently interconnected with the electric grid through the utilisation of single-phase inverters. The voltage and frequency at which the grid operates are not fixed, but rather can vary within the limits set by international norms. In addition, there is a continuous tightening of standards for power factor correction, total harmonic distortion, and dependability. Since grid operating conditions are dynamic, it is crucial to implement control algorithms that are both dependable and efficient, with flexible control parameters. With the goal of improving the efficiency and reducing the total harmonic distortion of the output current, this paper explores the topology of a single-phase inverter's configuration and its control algorithm. Therefore, deadbeat controllers that are continuously tuned based on the actual grid frequency are proposed as a solution to the control architecture with an appropriate Phase Locked Loop PLL, which addresses some practical issues with the control algorithm.

Abstract:
This paper is intended to check the thermal convection flow during a new solar air heater (SAH) test bench, which is conducted in the LASEM laboratory. In fact, the applied system includes two-passage heater solar air separated by an absorber. On the other hand, a glass piece is connected to the box prototype via a pipe. Then, the piece of the glass is attached to the front side of this device in which an absorber is inserted. Moreover, two circular holes are made on the same face of the box prototype. The first is an entry hole through which hot air goes inside, and an exit hole through which air is released into the surrounding area. The study was conducted using the Navier-Stokes equations associated with the k–ω turbulence model through the use of the newly released Ansys 17.0 software to characterize the aero-thermal structure of our new system operating in natural convection. In these conditions, it has been observed that the hot zone created on the mirror side receiving the solar radiation generates an ascendant movement. It goes from the bottom to the top and enters the box prototype. The same phenomenon is also created in the box where the airflow coming from the solar heat escapes into the environment. This movement created between the hot zone of the solar heat and the box prototype is also imposed in the cold zone of the solar heat on the heat-insulating side. In these conditions, the air movement is however from the top to the bottom. Indeed, the acceleration of the air velocity at the inlet of the solar heat is due to the change of the section which is more reduced by comparison to the rest of the air circulation duct. Based on our experimental results generated in a two-passage solar air heater connected to the box prototype, the computational approach and the simulation results were validated. By referring to the classic solar air heater with one passage, the energy efficiency measured in the same conditions was enhanced and presented the efficient one with an improvement of about 27%. Finally, the numerical results are compared to our experimental results and those obtained by the authors. The comparison proved a good agreement.

Abstract
This paper proposes training an artificial neural network (ANN) by a particle swarm optimization (PSO) technique to predict the flashover voltage of outdoor insulators. The analysis follows a series of real-world tests on high-voltage insulators to form a database for implementing artificial intelligence concepts. These tests are
performed in various degrees of artificial contamination (distilled brine). Each contamination level shows the amount of contamination in milliliters per area of the isolator. The acquisition database provides values of flashover voltage corresponding to their electrical conductivity in each isolation zone and different degrees of
artificial contamination. The results show that ANN trained by PSO can not only provide better prediction results, but also reduce the amount of computation efforts. It is also a more powerful model because: it does not get stuck in a local optimum. In addition, it also has the advantages of simple logic, simple implementation, and underlying intelligence. Compared to the results obtained by practical tests, the results obtained present that the PSO-ANN technique is very effective to predict flashover of high-voltage polluted insulators.

ABSTRACT
This paper presents a dead-beat control algorithm for Uninterruptible Power Supply (UPS) applications of single-phase inverters. The proposed control method requires the measurement of capacitor current and output voltage in order to keep the output voltage sinusoidal ensuring high dynamic performance even under load changes. The dead-beat controller optimizes the behavior of the system by eliminating the error between the output and the reference voltage without increasing the number of current sensors, which are costly, and eliminates load voltage distortions and restores the system state in the event of external shutdown-loop road interference. In this paper, we propose a capacitor current estimation based on the Luenberger observer. Processor-In-the-Loop (PIL) is a test method that allows us to create and evaluate controllers by running built-in C code on the DSP scheduled for the controller during simulated PSIM power phase control. It can be seen that the simulation results match the PIL test results, which proves the validity of the proposed controller.

Abstract—In this paper, a simulation of a barrier inserted in between two electrodes was made. The simulations took into account different conditions of the electrodes (point-plane, point-point, circle-plane and circle-circle) and the condition of the barrier (a barrier with and without a hole and pollution in the middle of the barrier). The software COMSOL Multiphysics, 5.6 version was used to simulate the effects these conditions have on the distributions of the electric potential and field (E-field). The results show that there big changes in the distributions under the different conditions where it be pollution or a hole in the barrier or even the electrodes shape.

Abstract—Thedesignofhighvoltageinsulatorneedsanextensiveresearchonthedistributionsofelectricfieldandelectric potential. In this paper, a 3D model of the cap and pin1512L insulator was created with and without pollution with the pollution having multiple values of relative permittivity to see the impact it makes on these distributions. AutoCAD 2018 software was used to model the insulator then later imported to the software COMSOL Multiphysics 5.6 a software based on the finite element method to simulate this work.

Ce travail vise à appliquer l’une des méthodes expérimentales appelées plan d’expérience pour analyse et prédiction de la tension de claquage d’une configuration pointe-barrière-plan artificiellement polluée et en l’appliquant aux câbles des lignes de transport d’électricité.

2- Domaine technique auquel se rapporte l’invention

Cette invention est l’application de la méthode des éléments finis dans le domaine de la haute tension et dans la spécialisation électrotechnique des réseaux électriques.

Abstract:
The widespread integration of renewable energy sources with the traditional power systems causes a considerable impact, such as the decrease of total inertia, damping properties and large frequency deviation. To tackle this issue, several literature proposed the virtual synchronous generator (VSG) emulation as an effective solution applied to power electronics inverters, i.e., grid forming and grid supporting power converters. In this paper, the VSG emulator in grid feeding structure is investigated within a simple week grid in order to bring support capabilities to the frequency and amplitude deviation. The frequency nadir at the point of common cohesion (PCC) can be reduced when more active power is required, whereas the voltage amplitude is reduced with reactive power demand. The small signal modeling of the VSG is addressed, taking into consideration inertia and damping variations to assess the transient response of active power and frequency during power variation. In order to validate the theoretical concepts, simulation tests have been carried out using PSIM platform.

Abstract:
The control of a DC/AC converter to provide a cost sinusoidal wave required in many application, is a challenging task. In the present paper, the deadbeat control algorithm has been proposed to generate a nearly sinusoidal waveform with zero steady-state error and low total harmonic distortion (THD). The controller is based on the output measurements to generate the required modulating signal (pulse-width), for controlling a single phase inverter. The derived deadbeat control algorithm requires the measurement of both capacitor current and output voltage which can be considered as a costly system. To tackle this disadvantage, we propose an estimation of the capacitor current based on Luenberger observer. The simulation results have confirmed the validity of the deadbeat control based current observer to enhance the output voltage, in the linear and nonlinear loads.

Abstract
This paper proposes training an artificial neural network (ANN) by a particle swarm optimization (PSO) technique to predict the flashover voltage of outdoor insulators. The analysis follows a series of real-world tests on high-voltage insulators to form a database for implementing artificial intelligence concepts. These tests are performed in various degrees of artificial contamination (distilled brine). Each contamination level shows the amount of contamination in milliliters per area of the isolator. The acquisition database provides values of
flashover voltage corresponding to their electrical conductivity in each isolation zone and different degrees of artificial contamination. The results show that ANN trained by PSO can not only provide better prediction results, but also reduce the amount of computation efforts. It is also a more powerful model because: it does not get stuck in a local optimum. In addition, it also has the advantages of simple logic, simple implementation, and underlying intelligence. Compared to the results obtained by practical tests, the results obtained present
that the PSO-ANN technique is very effective to predict flashover of high-voltage polluted insulators.

Keywords: flashover voltage, particle swarm optimization, prediction, artificial pollution, neural network

Abstract: In this paper, the response surface methodology (RSM) is used to predict the flashover voltage of a cap and pin 1512L insulator used by SONELGAZ Algerian Power Company (SPE). The pollution and conductivity are studied using a two-level central composite design. MINITAB 19 software is used to perform the regression analysis and analysis of variance (ANOVA) of the data, from which the full quadratic model is developed. The results show that both the pollution and conductivity have a significant effect on the response. The model validation shows the good agreement between the experiment’s obtained results and the predicted results. Therefore, the model could be used to predict the flashover voltage.


Keywords: flashover; response surface methodology (RSM); level of pollution (L); conductivities; ANOVA analysis

Abstract: In electrical distribution networks, the problem of harmonic pollution is becoming more and more worrying with the increase in the use of non-linear loads. The present work consists of the study of the dépollution of the electrical network by the compensation of harmonic current perturbation and improvement of current quality based on the three-phase four-wire parallel active filter. The results obtained by Matlab/simulation environment demonstrate the Importance of this work in harmonic filtering and reactive power compensation and show that is considered a modern solution to compensate for perturbation in the grid utility caused by nonlinear loads and offer good results for the THD of the current on the source side.

Keywords: Active Power Filter, Three-phase four wire Systems, Harmonic Compensation, Nonlinear loads.

Abstract: Knowledge of the presence of heterogeneous cavities in the insulating material is a major problem when the insulating material is used as cable insulation due to the occurrence of partial discharge (PD). Therefore, this study investigates the effect of the presence of such heterogeneous cavities in high-voltage cable insulation. Furthermore, the effect of changing the cavity location and size on the PD behavior under different operating conditions was investigated using the COMSOL program. The simulation results are in good agreement with the mathematical model in our study. The obtained results are in good agreement.


Keywords: Heterogeneous cavities, Electric field and potential, cables.

Abstract: Cross-linked polyethylene (XLPE) is increasingly used for medium to high voltage distribution cables for their excellent mechanical, thermal and electrical performance. In this paper, we present a numerical modeling of the XLPE power cable. A number of simulations are realized in order to analyze the influence of the meshing on the electric field and the potential distribution of XLPE insulation. The electric field and electrical potential are computed using the field computation program COMSOL Multiphysics 3.5. The results of simulation is plotted and analysed.

Keywords: XLPE cables, Mesh, Electric field, Electrical potential, Comsol.

Abstract: Cap and pin insulators are at risk for surface arcing phenomenon, especially in highly polluted or coastal areas. Therefore, it is very important to determine the electric field and electric potential distribution at industrial frequency. This paper presents a two-dimensional (2D) numerical model based on the finite element method to see the distribution of the potential and the electric field along the leakage distance of our studied model. The obtained simulation results found from the COMSOL Multiphysics 3.5 confirm the effectiveness of the proposed method, and good results are achieved.

Keywords: Insulators, Mesh, Electric field, Electrical potential, Comsol.

Abstract: Electrical insulators commonly known as suspension insulators can be used individually, but usually form part of a string to support an electrical conductor from a supporting structure. In this work, using COMSOL Multiphysics software, based on the finite element method (FEM), to study the potential and electric field distributions along the insulating surface of a string of high voltage 175 CTV insulators, widely used by the national electricity and gas company (Sonelgaz-Algeria) under AC voltage. We considered clean and destroyed cases. The study was carried out We used 2D electrostatic simulation in the AC/DC module. Numerical results showed a good agreement.


Keywords: String Insulators, destroyed insulator, Electric field, Electrical potential, Comsol.

Abstract: Several industrial sectors such as the installation and protection of energy transmission networks. The introduction of an insulating barrier significantly changes the breakdown voltage and improves the rigidity of a system without increasing the inter-electrode distance. Prediction of the breakdown voltage of a point-polluted barrier-point configuration is offered in this work by a numerical model based on the experimental design method (DOE). The results showed us that the location of the barrier is the most influential factor in the prediction of breakdown voltage. The calculated results are in good agreement with the experimental results.


Keywords: Point-barrier-plane, breakdown voltage, pollution, experimental design, prediction.

Abstract: Simulation of Three-Phase Four-Wire Shunt Active Power Filter (SAPF) reduced current measurement control method generated by nonlinear loads is investigated for operation of four-wire shunt active power filter (SAPF) under unbalanced load conditions is proposed in this work. Results obtained by simulations with Matlab /Simulink show that the proposed approach is an effective approach for compensating reactive power and harmonic currents of the load.

Keywords: Active Power Filter, Three-phase four wire systems, Harmonic Compensation

Abstract: Nowadays, a number of research papers have been carried out in the field of discharge and breakdown phenomena, particularly in the geometry of point plane. The prediction of the breakdown voltage of a point-barrier-plane configuration polluted by Minitab is offered in this work by a numerical model based on the experimental design method (DOE). To confirm the effectiveness of the proposed method, the results obtained is also verified with measurement values available in the literature, and a good correlation is achieved.
Keywords: DOE , point-barrier-plane, pollution, breakdown voltage, Minitab

Abstract: Today, power quality has become the most important issue in the electricity sector. Electric current in commercial and electrical installations is unquestionably degrading. However, these disturbances are generally caused by the connection to the network of non-linear loads which cause distortion of currents and voltage. In this work we present in an introductory part on the quality of energy as well as the origins of the harmonics. Next, we present the classic and modern solutions for deppolution the electrical networks. The objective of our work has devoted to the programming and discussion of the results obtained by the classical method.

Keywords: non linear charge, pollution, THD, harmonics, compensation.

Abstract: In service, the insulators must withstand both electrical stresses under normal operating conditions (over a wide range) and transient over voltages under abnormal conditions imposed by lightning, operating shocks and sandstorms on the insulating surface. This work is devoted to numerical simulation study of the behavior of pollution located on the surface of a high voltage cap and pin insulator used by Algeria's National Electricity and Gas Company. The approach followed and the results presented in this work open several perspectives as well as from the point of view of modeling and numerical simulation of physical phenomena affecting insulators of high voltage transport and distribution lines in humidity conditions (rain, dew…..). Discussions are made between the 2D/3D results to show that the numerical simulation always gives a sense of correct variation.

Keywords: cap and pin insulator, electric field, electric potential, numerical simulation.

Abstract: As transmission line voltages increase, the importance of insulator pollution research increases significantly. To determine the flashover behavior of contaminated high-voltage insulators and to determine the physical mechanism behind the phenomenon, the researchers were led to develop a model. This paper describes the application of an adaptive neuro-fuzzy inference system (ANFIS) to estimate the breakdown voltage of contaminated insulators. The results obtained are promising and ensure that the ANFIS technique can estimate the critical breakdown voltage of newly designed insulators with different operating conditions and represents an indispensable model for field simulations of different parameters of contaminated insulators.


Keywords: high voltage, insulators, fuzzy logic, polluted level, conductivity.

Abstract: The insulator is a solid insulating material which has a very high resistance to the passage of current. It is used to insulate conductors or live parts to prevent current flows. The prediction contains the respective confidence interval based on the fuzzy logic method. Various parameters, such as the conductivity and level of pollution of the triangular membership functions used for the fuzzification process, etc., are assigned different values in order to optimize the estimation of the flashover voltage phenomenon. Additionally, different tests for training the fuzzy system are applied and compared for their appropriateness in accurately predicting the flashover voltage.


Keywords: high voltage insulators, fuzzy logic, polluted level, conductivity.

In this chapter, the impact of the numerical parameters on the heat ventilation was studied in a box prototype. Particularly, a computational study and an experimental validation have been developed to compare the standard k-ω turbulence model, the BSL k-ω turbulence model, the SST k-ω turbulence model, the standard k-ɛ turbulence model, the RNG
k-ɛ turbulence model and the Realizable k-ɛ turbulence model. From the obtained results, it is noticed that the aerodynamic characteristics present the same emergence nevertheless the maximum values depend on the turbulence model. Particularly, it has been noted that the value founded with the standard k-ω turbulence model is nearest to the experimental results. This study tends to show that the standard k-ω turbulence model is the most efficient to study the air flow in the box prototype. For this model, the meshing effect on the CFD results was studied to choose the adequate mesh with a minimum calculated time. The numerical results were compared using experimental results developed in our laboratory.
The good agreements confirm the numerical method.

In this chapter, we are interested on the design and the realization of a new solar air heater test bench to investigate the efficiency of the solar system. The considered test bench consists of two passages solar air heater separated by an absorber and powered by a fan working in a delivery mode. On the glass side, it is connected to the box prototype
through a pipe. On this system, a glass is hanging on the front side and an absorber is inserted inside. The hot air flow is routed towards the box prototype. Two circular holes are located in the same face of the box prototype. The inlet hole allows the hot air supply. However, the outlet hole allows its escape into the ambient environment. Indeed, we have
developed numerical simulations to study the turbulent flow in the considered test bench over the day. In these conditions, it has been observed a decrease in the flow and an appearance of the recalculation zones in the first passage. This phenomenon is more prominent during the transition of the flow to the second passage. However, the flow
becomes uniform until the exit of the solar air heater. Via the pipe separating the solar air heater from the box prototype, a discharge area appears in the hole inlet and invaded the reverse wall. By comparing the local characteristics for the different instances, a similar appearance has been observed with a maximum value at t=12 hours. For the magnitude velocity, a small difference between the calculated values has been noted. However, this difference is more clear for the temperature distribution and the turbulent characteristics. For the energy efficiency, it presents very low values at the beginning of the day. With the increase of the temperature through the day, there is a gradual increase of the energy efficiency until t=12 hours, with a value equal to η= 31,8%. This technology will be very useful since it can provide sustainable energy and substitute the expensive traditional technologies.

Public cible : 1ere année Licence ST

Les travaux pratiques de physique constituent l'élément indispensable de l'étude de la physique. D'une part, on apprend les méthodes fondamentales de mesure, on se familiarise avec les appareils de mesure; on apprend à faire correctement les mesures et à évaluer leurs incertitudes.

D'autre part, on étudie certains phénomènes physiques, ce qui complète les connaissances reçues pendant les cours théoriques. On apprend également à étudier méthodiquement et logiquement les phénomènes et d'en tirer les conclusions nécessaires.

TP_01:
Mesurer les valeurs des résistances (inconnues) par les méthodes suivantes :
* Ohmmètre,
* Volt-ampèremétrique,
* Evaluer la précision relative pour chacune des méthodes.
TP_02:
But de notre TP:
* Mesurer une inductance avec la méthode volt ampérométrique et RLC série.
* Mesurer le coefficient de qualité.
TP_03:
But de notre TP:
* La mesure des capacités à l’aide de la méthode volta-ampèremétrique (V-A).
TP_04:
But de notre TP:

The solar air heater is a system which collects the radiation and transforms it into heat. The general idea is that the air is flowing through the solar collector and heat from the sun naturally raises the temperature of the air inside the collector. The advantage of this technology is that it is cheap and simple. The main objective of this work is to investigate the aerodynamic structure of the turbulent flow in a new solar air heater test bench, available in our LASEM laboratory. By using the ANSYS Fluent 17.0 software, the analysis was performed using the Navier-Stokes equations coupled with the standard k-ω turbulence model. The computational method and the simulation results were validated based on our experimental results developed in a tow passage solar air heater connected to a box prototype. The range of temperatures is very useful in industrial and domestic applications. The obtained results will be considered to produce better comfort conditions in case of supplying rooms.

Five phase fault tolerant ind uction motor (FPIM) with open end winding (OEW) can offer low torque ripple and it has a merit of high fault tolerant capability due to its large number of phases. In order to improve the operation performance under an open single phase . This paper propose s a Remedial Backstepping Control (RBSC) technique for a FPIM OEW with the ability to run the system before and after fault condition. Hence, the FPIM OEW losses are decreased, which improves the overall machine efficiency. The proposed RBSC technique lies in the orthogonal reduced order transformation matrix, which is derived from the fault tolerant current references, and a new zero sequence current related to torque ripple. Also, the effect of the open phase fault on the motor model under the transformat ion matrix is discussed. The simulation results of the proposed tec hnique under open single phase are provided , wherein we demonstrate the effectiveness of the proposed strategy with a fast dynamic and steady state performances as that under healthy operation.

In this paper, a fault-tolerant control staretegy for five-phase induction motor with stator open-end winding (FPIM-OEW)in electric vehicle (EV) is presented. The proposed strategy is able to run the control system before and after speed-sensor fault condition. Hence, the FPIM-OEW losses are decreased, which improves the overall machine efficiency. The proposed fault-tolerant control is derived from a backstepping control (to compensate speed-sensor fault). The simulated results are provided to verify the proposed technique under speed-sensor fault condition, in comparaison with conventional backstepping control,the proposed strategy, provides a good dynamic performance particularly in reduction of torque oscillations.

The vector control technique is one the most effective strategies for an electric machines. It aims to provide a decoupled control of torque and flux via a simple command structure. However, the main problem assiciated with the vector control is sensitivity of changes in sudden load torque. This paper presents a sensorless robust control for Dual Star Induction Machine (DSIM) based on Field Oriented Control (FOC) using Load Torque Estimation (LTE) under low speed conditions, dual observer structures will be incorporated to the main FOC sheme. First, a Model Reference Adaptative System (MRAS) observer is employed to obtain the speed estimates. Then, to improve the performance of speed tracking and increase the robustess against disturbance in the external speed control loop a LTE is adopted. This estimator can ensure an accurate speed tracking and can improve the disturbance rejection ability of the speed loop, which ensures robust speed control under different load disturbances. Simulation results show that the sensorless FOC techniqon LTE has a fast dynamic, better load diturbances rejection.

This paper tackles robust power control of a grid-connected brushless doubly-fed induction generator (BDFIG). With the implementation of a super twisting algorithm which is high-order sliding mode controller (HOSMC). This approach guarantees both the dynamic performance and the same robustness of traditional first order (SMC) algorithm and reduces the chattering phenomenon, which is the biggest disadvantage in the implementation of this technique. The developed algorithm relies on the decoupling control by implementing the strategy of oriented grid flux vector control. In order to enhance the desired performances, an attempt is made by controlling the generated stator active and reactive power in a linear and decoupled manner to ensure the global asymptotical stability, HOSMC approach is implemented. Therefore, an optimal operation of the BDFIG in sub- synchronous operation is used in addition to the stator power flows where the stator power factor is kept in a unity. The suggested method is examined with the Matlab/ Simulink software. The performances and the feasibility of the designed control are illustrated by simulation results.

Several investigators studied the natural convection heat transfer in tow passage solar air heater connected to a box prototype and much useful information is available in the literature. The use of the solar air collector is an effective technique to enhance the heat transfer to fluid flowing in the box prototype. In the present paper, we have developed numerical investigation of the natural convection flow in a new solar air heater test bench with two passages. By using the ANSYS Fluent 17.0 software, the analysis was performed using the Navier-Stokes equations coupled with the standard k-ω turbulence model. Based on the developed results, solar radiation has been found to be the main parameter which characterizes the thermal behavior of the system. Besides, exergy analysis has been carried out, and optimum conditions in which the system has the highest performance have been determined.

Backstepping control technique is receiving increased attention due to its simplicity and robust dynamic response. In this paper, a approach to improve the performance of Backstepping control of open-end stator winding five-phase induction motor (OEW-FPIM) with the fundamental and harmonic currents is developed. The proposed control is based on SVPWM technique, where fast torque response with low ripple in the stator flux and torque of OEW-FPIM can be achieved. Simulation results clearly demonstrate a better performance of the proposed method, which suggest that the combination of Backstepping-SVPWM technique with multi-phase motor have a great practical prospect in motor drives.

Direct Torque Control (DTC) technique is one of the most effective strategies for an electric machines. It aims to provide a decoupled control of torque and flux via a simple command structure. The aim of this paper is the study of the problems that can affect the operation of the speed loop for Induction Motor Open-End Winding (IM-OEW) through failures, especially broken bars fault, its impact on the control and operation of the motor. This paper presents a comparative study of the most powerful speed controllers for motor: proportional plus integral (PI) controller and a fuzzy logic (FL) controller. The awaited goal is to evaluate the speed controller is capable to improve the performance of the machine under faulty conditions. The obtained results proved the effectiveness of the DTC strategy with a fast dynamic, better load disturbances rejection and better tracking performance without overshoot when the FL speed controller employed, which ensures robust speed control under broken bars fault.

This document has essentially consisted in presenting a recent technique that allows the performance of tool steels to be increased by the creation of chromium carbide having hig chh aracteristics. In fact, after electrolytic deposition of a thin layer of pure chromium with a mean thickness of 10 ?m, on the steels Z210Cr12 and 100Cr6, the samples (layer / substrate) were annealed in the interval (1000 - 1100 C° ). In this temperature range, the deposited film is graduall cyo nverted into chromium carbide. The phase transformation that took place mainly by substrate carbon diffusion in the lay ewr as determined by X-ray diffraction and metallographic analysis. The
hardness and adhesion of the layers produced have evolv eadc cording to the treatment temperatures, their values thus obtained are in agreement with the evolution of the physicochemical properties determined by the physical means used. (Graphical abstract present optical microscope observations of a chromium layer on substrate Z200Cr12.X500 treat at1100°C spawning 02 hours).

Several investigating focus on the behavior of insulators under polluted conditions. That they are mathematical and physical models of insulators, experiments and simulation programs. Also experiments on critical flashover voltage are time consuming and have more limitations such as high cost and need for especial equipment’s. The main objective of this work is to predict the pollution flashover voltage under various meteorological factors using radial basis function (RBF) neural networks (ANN), under AC voltage. ANN structure with two numbers of layers intermediate, and six number of neurons by hidden layers (figure 1) are best-suited form. The results of the
proposed model are compared with the experimental result of anterior researcher. A comparison with the experimental results indicates the accuracy and goodness of ANN model.

The vector control technique is one of the most effective strategies for an electric machines. It aims to provide a decoupled control of torque and flux via a simple command structure. However, the main problem associated with the vector control is sensitivity of changes in sudden load torque. This paper presents a sensorless robust control for Dual Star Induction Machine (DSIM) based on Field Oriented Control (FOC) using Load Torque Estimation (LTE) under low speed conditions, dual observer structures will be incorporated to the main FOC scheme. First, a Model Reference Adaptive System (MRAS) observer is employed to obtain the speed estimates. Then, to improve the performance of speed tracking and increase the robustness against disturbance in the external speed control loop a LTE is adopted. This estimator can ensure an accurate speed tracking and can improve the disturbance rejection ability of the speed loop, which ensures robust speed control under different load disturbances. Simulation results show that the sensorless FOC technique based on LTE has a fast dynamic, better load disturbances rejection.

This paper proposes an investigation of dual three-phase SVM for six phase five-level inverter to control a Six Phase Induction Machine (SPIM). Therefore, a new modeling and control strategy of a five-level three-phase Diode Clamped Inverter (DCI) is presented.
The obtained modeling shows that modulated five-level voltages are obtained by combination of eight different three-level functions, which are called modulation functions. The main idea is to control the six-phase five-level inverter as two three-phase five-level inverter separately by Space Vector Modulation of the five-level three-phase Separate DC Source (SDCS) inverter. This enables a great simplification of the algorithm control for six phase five-level inverter drive. In six phase SVM, to control the six-phase five-level inverters as two three-phase five-level inverter with the same three-phase five-level SVM. Whereas the first three-phase inverter is composed by 1, 3, and 5 phases and the second three-phase is composed by 2, 4 and 6 phases. The simulation results of the Indirect Field Oriented Control (IFOC) of six-phase induction machine drive fed by stacked five-level inverters are given to highlight the performance of the proposed dual three phase SVM. Moreover, used five-level topologies reduce the currents THD distortion as well as the total semiconductor losses.

We propose in this paper a PI controller for Quadruple Tank System (QTS) in which we employ two bio-inspired optimization methods: Particle Swarm Optimization (PSO) and Biogeography Based Optimization (BBO) in order to adjust the parameters of the PI controller (kp, ki) to enhance the capability of traditional PI. Simulation results have confirmed both the effectiveness of the proposed control methods and the advantages of the optimized PI controller.

Ce polycopié a été conçu dans le but d’être considéré comme étant un support pédagogique. Ce cours "Réseaux Électriques", s'adresse aux étudiants en Master professionnelle, filière électrotechnique, en particulier les étudiants en Master 1 (premier semestre d'enseignement).
L’objectif du cours est de calculer et modéliser le réseau électrique. Ce document
comporte huits parties qui permettent de préparer les étudiants à la :
* Compréhension des différents concepts de base; les composants, et la représentation globale d’un réseau électrique à partir de la génération jusqu'à la distribution,
* Modélisation par la description du système d’unités relatives des différents éléments du réseau électrique (sources, lignes, transformateurs et charges),
* Modélisation des alternateurs, des Transformateurs de puissance et des charges dans un réseau électrique ainsi la Modélisation d’une ligne électrique,
* Modélisation d’une ligne électrique (Calcul des résistances, inductances et capacités linéiques (Paramètres de modélisation des lignes)),
Les autres parties sont consacrées à de préparer aussi les étudiants de voir :
 Les effets de la fréquence,
 Les conducteurs aériens vs les câbles isolés (souterrains),
 Transit de puissance, diagramme vectorielle et bilan de puissance des lignes en régime permanent,
 Régulation de tension. Impédance caractéristique et puissance caractéristique d'une ligne.
Ce support est constitué d'un plan de cours qui a pour but de donner les directives pédagogiques qui facilitent la compréhension et l’assimilation des leçons de "réseaux
électriques".
Enfin, j’espère bien que ce présent polycopié de cours donne intérêt aux lecteurs, et je serais très heureux de recevoir avec reconnaissance leurs remarques, leurs questions, critiques et suggestions.
L’ensemble des parties présentées dans ce document ont été effectuées au sein du Laboratoire de Génie Electrique (LGE) de l’Université Mohamed Boudiaf de M'sila.

Charges Horaires
 Cours Intégrés : 24h, 1h 30mn par semaine.

Mode d'évaluation
 Examen 100%
Pré requis
 Électrotechnique de base,
 Analyse des circuits électriques.

Public cible
 Les étudiants en 1er Année master professionnelle de l’université de M’sila,
 Filière : Électrotechnique,
 Spécialité : Commande Des Machines Tournantes.

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Open-End Winding Five-Phase Induction Motor (OEW-FPIM) are employed in applications where the reduction in the total power per phase and the highest level of overall system reliability is required, where a self-starting and operation under open phase(s) stand as the most salient features. This paper presents a simple, fast and robust open-phase fault control strategies for OEW-FPIM using parallel converters without common mode voltage: field-oriented control and backstepping control. The awaited goal is to evaluate the proposed approaches which give the best performance under open phase fault conditions. The performance of the two control approaches verified and compared by simulation. Provided tests analyze steady and transient states, including an open-phase fault condition. Obtained results prove the interest of the proposed approaches, which ensures the open-phase fault-tolerant capability of FPIM drives with parallel converters.

The aim of this paper is the study of the problems that can affect the operation of Induction Motor (IM) through failures, especially short-circuit faults between coils, to its impact on the control and operation of the motor. For this, we present a new method for the modeling of IM operating under short circuit fault between coils in the machine stator winding. This new method is based on the theory of electromagnetic coupling of electrical circuits. In this paper a comparative study between two most popular control approaches of IM: Direct Torque Control (DTC) and Backstepping Control. The two control strategies are compared in different terms such as their stability proprieties, torque and current fluctuations, taking into account the presence of the stator defects such as short-circuits between coils, the awaited goal is to evaluate the control is capable to improve the performance of the machine under faulty conditions. At last, the proposed two control strategies in this paper are verified by numerical simulation. The numerical validation results demonstrate that the proposed two control approaches have presented good performances of IM in faulty regime.

This paper designs an indirect power control method for brushless doubly fed induction generator (BDFIG), in which the stator is attached to grid with back-to-back space vector modulation (SVM) converter that converts the generated wind power. Our control method is a sliding mode control based on the theory of variable structure control. Specifically, the active and reactive powers, which are exchanged between the stator of the BDFIG and the grid in a linear and decoupled manner, are subjected to decoupled, vector control. In addition, a proportional integral (PI) controller was implemented to keep the DC-voltage constant for the back-to-back SVM converter. The efficiency of our control strategy was validated through simulation. The research greatly promotes the control of renewable energy generators.

In this work, we proposed multi-winding model for the simulation of broken bars in squirrel cage asynchronous machine, this model allows to study the influence of the broken bar defects on the behavior general of machines in different operating conditions (healthy and faulty). The breaking of the most frequent bars of the rotor causes oscillations of the torque, speed, and the current, the increase of the resistance of the rotor creates the defects proportional with the number of breaks bar K .The diagnosis fault using technique of single processing based on Spectrum analysis for detection broken bar. The results of the simulation obtained allowed us to show the importance of this technique for detection broken bar.

The flashover of pollution, observed on the insulators used in high voltage transmission, is one of the most important power transmission stakes. It is a very complex problem due to several factors including the modelling difficulties of complex shapes of insulators, different pollution densities at different regions, non-homogeneous pollution distribution on the insulator surface and unknown effect of humidity on the pollution. In the literature, some static and dynamic models have been developed by making some assumptions and omissions to predict the flashover voltages of polluted insulators. This paper aims to experimentally analyse the flashover process and simulation of the distributions of the potential and the electric field under 50 Hz applied voltage on a real model simulating the 175CTV outdoor insulators largely used by the Algerian Company of Electricity and Gas (SONELGAZ). This real model is studied under non-polluted (distilled water), and polluted (distilled water and sand) environments. The simulations were carried out by using the COMSOL multiphysics software. This program uses the finite element method to solve the partial differential equations that describe the field. Experimental results made in the laboratory and simulation results are original and found to be congruent.

This paper investigates the unsteady state of the heat ventilation in a box prototype with two holes. The CFD simulations were conducted using ANSYS Fluent 17.0 software, which solves the Navier-Stokes equations in conjunction with the standard k-ω turbulence model and by a finite volume discretization method. The presented results, consisting of the distribution of the velocity fields, the temperature, the total pressure and the turbulent characteristics, are very useful to determine the time required for the heating operation and to shrink the energy consumption of the buildings. The comparison between the founded results affirms that the heating time presents a straight effect on the velocity fields. However, for the temperature, the box prototype requires more time and more energy to warm up. In our application, we confirm that the duration of 30 s is sufficient to allow the heating of the box prototype. Indeed, the numerical results compared using the experimental data developed in our laboratory confirms the validity of the numerical method. The good agreements validate the considered computational method.

The Direct Torque Control (DTC) of induction motor (IM) constitutes a vast subject because its implementation requires no position sensor, and which are characterized by fast dynamic response for IM. However, the DTC technique uses the stator resistance (R s ) for estimation of the stator flux. Owing to this, the control has a disadvantage that the R s variation due to changes in temperature causes an estimation error of stator flux and hence in the electromagnetic torque, particularly during low-speed operation, this leads to a degraded performance of the DTC technique. Therefore, continuously estimated of the R s is required. In this paper, a method for stator resistance estimation of induction motor fed by a three-level neutral point clamped inverter based on DTC technique has been proposed in which the R s value is updated during operation. This estimation method is obtained using a fuzzy logic controller. The main objective of this estimation scheme is that the change of R s can be traced to compensate the effects and improve performance DTC. The system performance is verified by simulations. The results obtained have shown the effectiveness of the proposed method.

This paper proposes a robust sliding mode control of grid-connected brushless doubly fed induction generator (BDFIG) used in wind-energy conversion systems. The designed controller is based on the sliding mode control combined with the stator power winding flux oriented vector principle. The stator of this machine incorporates two sets of three phase windings with different number of poles, power winding (PW) and control winding (CW). An original control strategy that based on a variable structure control theory, called also sliding mode control (SMC), is applied to achieve independent control of active and reactive powers that has been developed and the performance of proposed block diagram of the variable speed constant-frequency (VSCF) wind energy generation system is validated in the Matlab/Simulink environment and the obtained computer simulation results confirm the effectiveness of this control strategy.

The induction machine is the most used in industrial field because of their Safety, reliability, efficiency, and performance. The main objective of our work is the fault detection the rotor bar in induction machine, and describing the various defects that can happen on machine. We propose a multi-winding model of the asynchronous machine for the simulation of broken bar. This model makes to study the influence of a bar fault and evaluation machine behavior in healthy and faulty case. For detection fault using technique of single processing, is based on the spectrum analysis of the stator current. The results of the simulation obtained allowed us to show the importance of this technique and detect the presence of a fault and to locate its source.

The critical flashover voltage of a polluted insulator is a significant parameter for the reliability of power systems. Several approaches have been developed for the estimation of the flashover voltage. The main objective of our work is the implementation of an artificial intelligence method which is the artificial neural network (ANN) for the prediction of the flashover voltage of an artificially polluted high voltage insulator under MATLAB. This technique will have to take into account the variation of the conductivity and the level of pollution of the state of the insulator. The results obtained show that this method has been successfully applied. There is a good agreement between the calculated results and the experimental results.

Improving air quality can support efforts to mitigate climate change. The challenge that we are facing is, therefore, to ensure that our air and climate policies focus on win-win scenarios. For this, we have studied the heat convection flow in a new solar air heater test bench, available in our LASEM laboratory. By using the ANSYS Fluent 17.0 software, the analysis was performed using the Navier-Stokes equations coupled with the standard k-? turbulence model. The computational method and the simulation results were validated based on our experimental results developed in a tow passage solar air heater connected to a box prototype. The range of temperatures is very useful
in many applications such as industrial and domestic applications.

Brushless doubly fed induction generators (BDFIG) show commercial promise for wind-power generation due to their lower capital and operational costs and higher reliability as compared with doubly fed induction generators. This paper proposes a robust sliding mode control of grid-connected brushless doubly fed induction generator (BDFIG). The developed algorithm is based on the decoupling control by using oriented grid flux vector control strategy. The decoupling of the active and the reactive stator powers insures an optimal performance of the BDFIG at the sub-synchronous region. The stator of this machine incorporates two sets of three phase windings with different number of poles, power winding (PW) and control winding (CW). The proposed method is tested with the Matlab/Simulink software. Simulation results illustrate the performances and the feasibility of the designed control.

The use of efficient systems in order to reduce the energy consumption presents in nowadays a great challenge. Indeed, the use of the renewable energy in the heat ventilation of building application becomes very crucial. In this work, we are interested on the study of the turbulent flow in a box prototype. In this prototype, a solar system is integrated to supply the hole inlet with a hot air. The numerical model is based on the resolution of the Navier-Stokes equations in conjunction with the standard k-ω turbulence model. These equations were solved by a finite volume discretization method using the commercial CFD code ANSYS Fluent 17.0. To accurate the numerical results, the meshing effect on the numerical results was studied to choose the optimal mesh with a minimum calculated time. The numerical results were compared using anterior results developed in our laboratory. The good agreements confirm the validity of the numerical method.

In this work, the turbulent flow was studied in a new SAH (solar air heater) test bench. Particularly, we have considered the natural and the forced convection modes. The used test bench is composed by two passages separated by an absorber and powered by a fan working in a delivery mode, placed in the inlet side the insulation, for the forced convection mode. On this system, a glass is hanging on the front side and an absorber is inserted inside. On the glass side, it is connected to the box prototype through a pipe. The hot air flow is routed towards the box prototype. Two circular holes, are located in the same face of the box prototype. The inlet hole allows the hot air supply. However, the outlet hole allows its escape into the ambient environment. By using the ANSYS Fluent 17.0 software, the Navier-Stokes equations coupled with the standard k-ω turbulence model were solved. The numerical results were compared with our experimental data, established in the second passage of the SAH test bench. The good agreement confirms the validity of the numerical method. The range of temperatures is very useful in many applications such as industrial and domestic applications.

The electrical effects can be written by two magnitudes the field and the electrostatic potential, for the determination of the distribution of the field and the electric potential along the leakage distance of the polluted insulator, the comsol multiphysics software based on the finite element method will be used. The objective of this paper is the modeling electric field and potential distribution in Two Dimensions by the Finite Element Method on a model of insulator simulating the 1512L outdoor insulator used by the Algerian company of electricity and gas (SONELGAZ). This model is under different conductivity, applied voltage, position of clean layer and width of clean layer. The computer simulations are carried out by using the COMSOL multiphysics software. This paper describes how Comsol Multiphysics have been used for modeling of the insulator using electrostatic 2D simulations in the AC/DC module. Numerical results showed a good agreement.

The knowledge of the distribution of the electric field within and around high voltage equipment is a crucial aspect of the design, exploitation and performance of high voltage insulators. It could be useful for the detection of defects in insulators. The objective of this study is predicting the behavior of polluted insulator under AC voltage. For thus, the distribution of the potential and the electric field along high voltage insulator is investigated using a numerical method. The commercial Comsol Multiphysics proved to be one of the best software used in 2D modeling. The potential and the electric field distributions along this insulator are simulated under various conditions: the two cases: clean and polluted insulators and applying different conductivity values. We used electrostatic 2D simulations in the AC/DC module. The results are auspicious and promising.

The objective of this study is to predict the flashover voltage of a high-voltage insulator artificially contaminated using artificial intelligence (AI). First, practical tests were performed on a high-voltage insulator to collect a database used in the implementation of the artificial intelligence concept. These tests were realized for different levels of artificial pollution (saline distilled water). Each pollution level presented an amount of artificial pollution, in milliliters, in each petticoat (zone) of the insulator. The collecting database gives flashover voltage values corresponding to different amounts of artificial pollution in each insulator zone and its conductivity. Second, we have introduced fuzzy logic (FL) and artificial neural networks (ANN) as two AI techniques to predict the flashover voltage of the high-voltage insulator and to estimate the insulating state of artificial pollution. The proposed prediction concepts based on FL and ANN are implemented using MATLAB’s graphical user interface. Finally, a comparison was made between the results obtained by AI and practical ones. The database used in this comparison is different from that used in concepts based on FL and ANN implementation. The obtained results show a high efficacy of FL and ANN techniques in predicting the flashover voltage of high-voltage insulators compared with those obtained by practical tests.

In this paper, the impact of the conductivity and the distribution of pollution on the behavior of the high voltage insulator cap and pin 1512L, artificially polluted is
described. An experimental model in form of a disc is proposed. This experimental model reproduces the real model which is the 1512L insulator. Besides, a comparative study is presented. For this comparative study, different solutions are adopted to s`imulate the pollution (containing NaCl + distilled water) that has different
conductivities for a discontinuous distribution of the pollution on the insulator under an AC voltage. Furthermore, the influence of the pollution on the flashover
voltage and the leakage current is studied. Finally, the behavior of real and experimental model of the insulator is investigated.

This paper presents a work devoted to the impact study of the pollution severity on the energy level dissipated on high voltage insulator. Pollution of high voltage insulators is a factor of prime importance in the quality and reliability of power transmission. It causes the circumvention of high voltage insulators. However, when it is wet, it causes the dissolution of salts and the formation of an electrolyte layer on the surface of insulators, thus reducing dielectric strength. Pollution generally poses few problems. However, when it is humid, it causes the dissolution of salts and the formation of an electrolytic layer on the insulator surfaces; as a result, it reduces their dielectric rigidity.
The aim of this paper is the experimental study of the flashover process and the distributions of the potential and the electric field pollution carried out under 50 Hz applied voltage on a circular model simulating the 1512 L outdoor insulator largely used by the Algerian company of electricity and gas (SONELGAZ). This circular model is under different surface conductivity and different level of uniform discontinues pollution.
The computer simulations are carried out by using the COMSOL Multiphysics 3.5 software. This program uses the finite element method to solve the partial differential equations that describe the field. Original experimental results made in the laboratory are presented and compared with a real insulator, and simulations presented in this paper are originals.