Publications internationales

2022
Zine Ghemari, Salah Belkhiri, Salah Saad. (2022), Improvement of the relative sensitivity for obtaining a high performance piezoelectric sensor. Research square https://www.researchsquare.com/article/rs-1408892/v1

Résumé: A piezoelectric sensor is a sensor using the piezoelectric effect in order to measure physical quantities such as pressure, acceleration, or any other physical quantity generating stresses or mechanical deformations through active materials (magnetic, electrical, thermal , mechanical...). In this paper, the operating principle of the piezoelectric sensor is defined in detail and it is translated to mathematical model (ie the modeling of this type of sensors). This developed model is related the accelerometer electrical parameters with their mechanical parameters, and simulation of this model allows to choose the appropriate damping rate of the sensor which minimizes measurement error and improves accuracy and sensitivity of this one. The proposal of a new relation links the relative frequency by the natural frequency of the piezoelectric accelerometer makes it possible to minimize the resonance phenomenon effect, to facilitate the suitable choice of the accelerometer and to protect it

2021
Yahia Laamari, Samia Allaoui, Abdelmalik Bendaikha, Salah Saad. (2021), Fault Detection Between Stator Windings Turns of Permanent Magnet Synchronous Motor Based on Torque and Stator-Current Analysis Using FFT and Discrete Wavelet Transform. International information and engineering technology Association : Lavoisier, http://www.iieta.org/journals/mmep/paper/10.18280/mmep.080220

Résumé: The main idea of this article is to model and analyze the short circuit fault between the turns of the stator windings of a Permanent Magnet Synchronous Motor (PMSM). To accomplish this objective, a numerical model describing both the healthy and defective state of the PMSM is developed. Besides, this dynamic model is simulated and tested to study motor behavior under different fault conditions. Also, the frequency domain analysis based on the famous fast Fourier transform (FFT) as well as the time-frequency analysis using discrete wavelet transform (DWT) is established. This allowed extracting signatures related to the presence of an inter-turn short-circuit (ITSC). In the proposed method, ITSC detection is based on the decomposition of stator currents and electromagnetic torque. DWT and spectral analysis show that the low-frequency wavelet details as well as the total harmonic distortion (THD) can be easily used as a good short-circuit indicator. The simulation results of a healthy and faulty motor show the effectiveness of these two approaches but with a significant superiority of the DWT over the FFT.

Zine Ghemari, Saad Salah, Mabrouk Defdaf. (2021), Appropriate Choice of Damping Rate and Frequency Margin for Improvement of the Piezoelectric Sensor Measurement Accuracy. Journal of Advanced Manufacturing Systems : World Scientific Publishing Company, https://www.worldscientific.com/doi/abs/10.1142/S0219686721500256

Résumé: In industrial installations, the piezoelectric sensor plays a very important role in the monitoring of electromechanical systems and the detection of their early defects. Modeling is the mathematical presentation of the operating principle of the piezoelectric sensor, it allows to transform this principle to equations, these equations allow to improve the performances of this sensor and to propose new designs. In this work, the effects of piezoelectric materials are explained and the piezoelectric sensor is described. The physical behavior of the sensor is modeled and extracted a formula relates the accuracy as a function of relative movement (vibratory displacement). The model developed is validated by simulation and by experimental tests and the appropriate choice of the damping rate makes it possible to improve the parameters of the piezoelectric sensor and to progress the vibratory analysis technique.

Khalid Faiza, Rabah Manaa, Salah Saad, Hacene Ameddah. (2021), A Study of the Thermo-Mechanical Behavior of a Gas Turbine Blade in Composite Materials Reinforced with Mast. Revue des Composites et des Matériaux Avancés-Journal of Composite and Advanced Materials : Lavoisier, http://www.iieta.org/journals/rcma/paper/10.18280/rcma.310205

Résumé: The turbine blades are subjected to high operating temperatures and high centrifugal tensile stress due to rotational speeds. The maximum temperature at the inlet of the turbine is currently limited by the resistance of the materials used for the blades. The present paper is focused on the thermo-mechanical behavior of the blade in composite materials with reinforced mast under two different types of loading. The material studied in this work is a composite material, the selected matrix is a technical ceramic which is alumina (aluminum oxide Al2O3) and the reinforcement is carried out by short fibers of high modulus carbon to optimize a percentage of 40% carbon and 60% of ceramics. The simulation was performed numerically by Ansys (Workbench 16.0) software. The comparative analysis was conducted to determine displacements, strains and Von Mises stress of composite material and then compared to other materials such as Titanium Alloy, Stainless Steel Alloy, and Aluminum 2024 Alloy. The results were compared in order to select the material with the best performance in terms of rigidity under thermo-mechanical stresses. While comparing these materials, it is found that composite material is better suited for high temperature applications. On evaluating the graphs drawn for, strains and displacements, the blade in composite materials reinforced with mast is considered as optimum.

Samia Allaoui, Yahia Laamari, Kheireddine Chafaa, Salah Saad. (2021), Position and Speed Estimation of PMSM Based on Extended Kalman Filter Tuned by Biogeography-Based-Optimization . Journal Européen des Systèmes Automatisés : Lavoisier, https://www.iieta.org/Journals/JESA/Current

Résumé: In a sensorless control of PMSM based on Extended Kalman Filter (EKF), the correct selection of system and measurement noise covariance has a great influence on the estimation performances of the filter. In fact, it is extremely difficult to find their optimal values by trial and error method. Therefore, the main contribution of this work is to prove the efficiency of Biogeography-Based-Optimization (BBO) technique to obtain the optimal noise covariance matrices Q and R. The BBO and EKF combination gives a BBO-EKF algorithm, which allows to estimate all the state variables of PMSM drive particularly, the rotor position and speed. In this paper, three evolutionary algorithms namely Particle Swarm Optimization (PSO), genetic algorithms (GAs) and BBO are used to get the best Q and R of EKF. Simulations tests performed in Matlab Simulink environment show excellent performance of BBO-EKF compared to GAs-EKF and PSO-EKF approaches either in resolution or in convergence speed.

Zine Ghemari , Saad Salah and Mabrouk Defdaf*. (2021), Appropriate Choice of Damping Rate and Frequency Margin for Improvement of the Piezoelectric Sensor Measurement Accuracy. Journal of Advanced Manufacturing Systems : World Scientific Publishing Company, https://www.worldscientific.com/doi/abs/10.1142/S0219686721500256?download=true&journalCode=jams

Résumé: In industrial installations, the piezoelectric sensor plays a very important role in the monitoring of electromechanical systems and the detection of their early defects. Modeling is the mathematical presentation of the operating principle of the piezoelectric sensor, it allows to transform this principle to equations, these equations allow to improve the performances of this sensor and to propose new designs. In this work, the e®ects of piezoelectric materials are explained and the piezoelectric sensor is described. The physical behavior of the sensor is modeled and extracted a formula relates the accuracy as a function of relative movement (vibratory displacement). The model developed is validated by simulation and by experimental tests and the appropriate choice of the damping rate makes it possible to improve the parameters of the piezoelectric sensor and to progress the vibratory analysis technique.

Naima Grabsia, Elias Hadjadj Aoul, Salah Saad. (2021), An Improved Fast Kurtogram Based on an Optimal Wavelet Coefficient for Wind Turbine Gear Fault Detection. Journal of Electrical Engineering & Technology : Springer, https://link.springer.com/article/10.1007/s42835-021-00937-9

Résumé: Serious failures of wind turbine drive-trains occur in gear which plays an essential role. Owing to the complicated vibration signal of faulty gear and the characteristic fault frequency buried in the background noise. Thus, detecting a defect of this component with classical methods is a great challenge. In order to overcome this issue, a combined technique of time–frequency analysis based on Morlet wavelet coefficient (MWC) and fast kurtogram (MWC-FK) is proposed for gear fault detection. The Morlet wavelet (MW) is able to detect components impulses and the fast Kurtogram (FK) is appropriate for environmental noise elimination and extracts the impulses in the filtered signal. First, the wavelet coefficient is obtained using the continuous Morlet wavelet transform decomposition for further analysis. Then, the wavelet coefficient signal that has the highest value of the kurtosis index is chosen. Finally, the selected signal is filtered by an optimal band-pass filter based on fast kurtogram. In order to confirm the usefulness and robustness of the proposed method, a real vibration signal of wind-turbine pinion with fault is used in this work. The results have showed the efficiency of the proposed method in gear fault detection and the extraction of fault characteristic frequencies by the squared envelope spectrum (SES) of the filtered Morlet wavelet coefficient signal.

2020
Meghni Billel, Ouada Mehdi, Salah Saad. (2020), A novel improved variable-step-size P&O MPPT method and effective supervisory controller to extend optimal energy management in hybrid wind turbine. Electrical Engineering : Springer, https://link.springer.com/article/10.1007/s00202-019-00911-9

Résumé: This paper describes a new maximum power point tracking (MPPT) based on a variable structure “Automatic Systems approach” in order to modify and improve the conventional method perturb and observe. Therefore, the main contribution of this work is related to the developments in advanced control and management system applied to hybrid wind turbines (WT). The objective is to strengthen the extraction capacity of wind power in order to obtain an extended operational range “operating areas II and III.” In other terms, the multi-objective optimization on hybrid WT based on sophisticate control system and robust management reliable to hybrid WTs is performed to design a perfect control system. This system requires a very complicated adaptation between the second-order sliding mode control (SOSMC)-based speed control, a novel MPPT technique modified enhanced perturb and observe “MEPO,” system limitation and system energy storage. In addition, to improve the quality of the electrical energy introduced into the grid, a new efficient and robust strategy control based on direct power control-space vector modulation (DPC-SVM-SOSMC) implemented in the network side of the converter is proposed. The feasibility and effectiveness of the proposed control system and the new switching algorithm that coordinates the control (the multi-objective optimization) are validated under entire operating range (II and III). The results have showed that, compared with the conventional control system, the proposed scheme provides higher power conversion efficiency, offers better grid power quality and has better dynamic performances as well as a very robust adaptation against the uncertainties of the parameters and external disturbances.

Nasreddine Lahouasnia, Mohamed Faouzi Rachedi, Djalel Drici, Salah Saad. (2020), Load Unbalance Detection Improvement in Three-Phase Induction Machine Based on Current Space Vector Analysis. Journal of Electrical Engineering & Technology : Springer, https://link.springer.com/article/10.1007/s42835-020-00403-y

Résumé: Although the asynchronous machine is renowned for its qualities of robustness, reliability, low cost of construction and efficiency, it happens nevertheless that faulty operations may appear during its lifetime. Numerous papers have studied the mechanical defects detection in electric motors using stator currents. The present paper is focused on the detection of load unbalance in three-phase induction motor relying on stator currents analysis. The proposed approach is based on the analysis of current space vector transformation, which takes in consideration all the information provided by the induction machine, this information is analysed by the means of Power Spectral Density and the Wavelet Packet Decomposition techniques. For this purpose, an experimental setup is designed to conduct experimental tests and show the advantages of space vector transformation compared to single-phase analysis. The obtained results are discussed and analysed.

Salah Bekhiri, Zine Ghemari, Salah Saad, Boudechiche Ghania. (2020), Improvement of the Vibratory Analysis by Enhancement of Accelerometer Characteristics. Sensor Letters : American Scientific Publishers, https://www.ingentaconnect.com/content/asp/senlet/2020/00000018/00000001/art00007;jsessionid=9cop643tp5tic.x-ic-live-01

Résumé: In this work, the mathematical model suitable for the operating principle of the piezoelectric accelerometer is extracted then this model which connects the accuracy and the measurement error according of the frequency ration and the damping rate is validated by simulation. The model developed makes it possible to improve the performances of the accelerometer such as precision, sensitivity and reliability as well as to propose a new conception of the latter. A comparative study is made to show the importance of our results compared to literature, these results have showed that a suitable and appropriate choice of damping ratio develops the accelerometer parameters and enhances the vibratory analysis technique.

Fares Zaamouche, Salah Saad, Larbi Hamiche . (2020), Discontinuous PWM Applied for a Three-Phase Five-Level CHB Inverter Fed by PV Solar-Boost Converter . European Journal of Electrical Engineering : Lavoisier, http://www.iieta.org/journals/ejee/paper/10.18280/ejee.220209

Résumé: Among the renewable energy sources, solar energy has been a big part interest sources in past few years. With the development of power electronics technology, the multi-level inverters are widely used for the production of electrical energy. There are several variants of these converters, the cascaded-H bridge multi-level inverter (CHB) is more advantageous compared to the other arrangements, since each H bridge inverter has an independent DC source. In this paper, a three-phase five-level CHB inverter feeding by a PV solar-Boost converter system using a discontinuous pulse width modulation (DPWM) presented, improved the power quality by reducing the total harmonic distortion (THD) at the outputs voltage and current and also reducing inverter switching losses. The main idea of this work, is that the DPWM technique is used, studied and analyzed in detail to control the multilevel inverters topologies, and it can have many advantages to the other PWM techniques like space vector modulation (SVPWM). The simulation was performed in the MATLAB/Simulink software using an induction machine like a load and the obtained results are presented and analyzed.

Reffas O, Sahraoui Y, Nahal M, Hadiby Ghoul R, Saad S. (2020), Reactive energy compensator effect on the reliability of a complex electrical system using Bayesian networks. Eksploatacja i Niezawodnosc – Maintenance and Reliabilityhttp://www.ein.org.pl/sites/default/files/2020-04-12.pdf

Résumé: The static synchronous compensator is presented in order to improve an electrical network system performance. The present work aims to develop a Bayesian methodology for assessing the time-variant reliability of a complex electrical system taking into account reactive energy compensator (STATCOM). However, the complex aspect is not only related to the complexity of electrical system components architecture, nevertheless is allied to electrical network and STATCOM interactions. The Bayesian network is used for coping with this complexity constraint. The reliability-based assessment of reactive energy compensator effect is applied to a real case of a complex electrical system. The proposed Bayesian methodology application reveals that the STATCOM has a significant influence on electrical system reliability and the developed model can provide valuable information for decision makers to improve the system reliability performance.

Mohamed Lamine Nacer, Hamid Kherfane, Sandrine Moreau, Salah Saad. (2020), Robust Observer Design for Uncertain Lipschitz Nonlinear Systems Based on Differential Mean Value Theorem: Application to Induction Motors. Journal of Control, Automation and Electrical Systems : Springer US, https://link.springer.com/article/10.1007/s40313-020-00658-w

Résumé: In this paper, we present a robust observer design for Lipschitz nonlinear systems subject to parametric uncertainties and external disturbance, with its application to state estimation of an induction motor. First, the developed approach combined the differential mean value theorem with sector nonlinearity transformation to reformulate the nonlinearity term in the estimation error dynamics into a convex combination of vertex matrices as quasi-linear parameter varying system. Then by using an extension of H∞ criterion and pole placement technique, less conservative and sufficient stability conditions of the studied observer are derived and cast in terms of linear matrix inequalities (LMIs). Next, the observer gain is computed offline by solving these LMIs through the YALMIP software. Finally, the results of simulation were carried out with three scenarios to demonstrate the efficiency and effectiveness of our technique and to show its uperiority in terms of robustness compared to others methods previously reported in some literature.

Bellal Belkacemi, Salah Saad, Zine Ghemari, Fares Zaamouche, Adel Khazzane. (2020), Detection of Induction Motor Improper Bearing Lubrication by Discrete Wavelet Transforms (DWT) Decomposition. Instrumentation Mesure Métrologie : Lavoisier, http://www.iieta.org/journals/i2m/paper/10.18280/i2m.190504

Résumé: The present paper deals with healthy and improper bearing lubrication signals analysis using Discrete Wavelet Transform (DWT) enhanced by MATLAB/ Wavelets toolbox analysis. The identification of bearing faults from the time or the frequency domain are difficult due to non stationary vibration signal. Therefore, for more accurate faults information and identification of bearing with lubrication defects (improper or absence of lubrication), the DWT is used. The validation of this procedure is conducted by an experimental setup designed for vibration signal acquisition and the complete analysis is finalized by MATLAB/ Wavelets toolbox. The recorded data used for the validation are the signals of healthy and un-lubricated bearing driven at a rotation speed of 1500 rpm by 0.78 KW three phase induction motor. From the obtained results it can be observed that, for medium speeds DWT decomposition enhanced by MATLAB Wavelets Toolbox procedure is efficient for improper lubricated bearing related faults diagnosis and detection.

2019
Ghemari Zine, Saad Salah. (2019), Enhancement of capacitive accelerometer operation by parameters improvement. International Journal of Numerical Modelling Electronic Networks Devices and Fields : Wiley, https://onlinelibrary.wiley.com/doi/abs/10.1002/jnm.2568?af=R

Résumé: In the present paper, a mathematical model suitable for capacitive accelerometer is developed by applying the fundamental principle of dynamics and validated by simulation and experiment test. This model aims to visualize the capacitance variation of the accelerometer as a function of relative movement frequency. The main motivation key role of this paper is to propose a capacitive accelerometer with improved parameters. Therefore, in capacitive detection, the damping rate choice is directly influenced by the variation in capacitance; for this purpose, a comparative study of three damping rates is carried out. The first accelerometer is used in practical tests, the second is presented and studied in recent literature, and the third is the accelerometer proposed in this work. A new expression is extracted from the damping ratio as a function of measurement error to determine the damping rate according to a desired measurement error value. Finally, a new capacitive accelerometer with improved parameters having many advantages over the existing accelerometers is obtained. Simulation and experimental results have enabled us to recommend a new capacitive accelerometer design with very low measurement error (limited to 0.25%), high accuracy (equal to 99.75%), high sensitivity and reliability, and low electrical energy consumption.

Ghemari Zine, Saad Salah. (2019), The use of mechanical sensitivity model to enhance capacitive sensor characteristics. Analog Integrated Circuits and Signal Processing : Kluwer Academic Publishers, https://link.springer.com/article/10.1007/s10470-018-01383-w

Résumé: Vibration analysis is a conditional preventive maintenance technique that measures the level of vibratory motion by a measuring chain containing a vibration sensor, an amplifier and an FFT analyzer. In the present work, the vibratory analysis technique is improved on the basis of vibration sensor (capacitive sensor) developments. A suitable capacitive sensor mathematical model is developed thus; a formula of its mechanical sensitivity according to the capacitance is extracted. Experimental and simulation tests are conducted to validate the developed model. A damping rate equal to 0.68 is chosen to reduce the measurement error to a value not exceeding 0.5% in order to increase the accuracy to a value greater than or equal to 99.5%, consequently the sensor mechanical sensitivity is optimized. Finally, the simulation of the developed model is carried out for two capacitive sensors. The first sensor is used in the experimental tests and has a damping rate equal to 0.64 and the second is the sensor proposed in this work, having a damping rate equal to 0.68. The comparison of the obtained results has showed that the damping rate of 0.68 has greatly improved the capacitive sensor performances.

Salima Khaoula Reguieg, Zine Ghemari, Tarak Benslimane, Salah Saad. (2019), Modeling and Enhancement of Piezoelectric Accelerometer Relative Sensitivity Article. Sensing and Imaging An International Journal : Springer, https://link.springer.com/article/10.1007/s11220-018-0222-y

Résumé: The piezoelectric accelerometer is an electronic instrument based on the direct effect of the piezoelectric material, this device is widely used in the industries to monitor and detect defects of rotating machines in an early stage. In this paper, a thorough study of the piezoelectric accelerometer is carried out to understand its design and operation principle. A mathematical model of the accelerometer is developed based on Newton motion law then a new relative sensitivity equation in function of measurement error is extracted. This new equation has allowed a significant reduction in the measurement error, a maximum improvement in the precision and an optimization of the piezoelectric accelerometer relative sensitivity by the appropriate choice of damping rate. These improvements have optimized the accelerometer parameters and performances.

Zine Ghemari, Salah Saad, Khatir Khettab . (2019), Improvement of the Vibratory Diagnostic Method by Evolution of the Piezoelectric Sensor Performance. nternational Journal of Precision Engineering and Manufacturing : Springer, https://link.springer.com/article/10.1007/s12541-019-00154-5

Résumé: Vibration analysis is an important means in the industrial field to monitor electromechanical systems; their evolution can provide the correct information on vibration. For this purpose; it is necessary to focus the study on improving the piezoelectric sensor performance to progress the vibration analysis method. In industry, the piezoelectric accelerometer is the instrument often used to monitor rotating machines and detect their defects in an early stage. In this paper, piezoelectric detection is studied to understand the operating principle of the piezoelectric accelerometer and translate it into a mathematical model. Validation of the model developed of measurement accuracy and measurement error as a function of relative vibration movement by simulation and experimental tests is performed. Using this validated model, the improvement of the characteristics and performance of this sensor can be achieved as well as a new conception of the latter can be proposed. This new design of piezoelectric sensor aims to obtain more accurate results and to provide correct information’s on the vibratory level. A comparative study is made to show the importance of our results compared to literature, these results have showed that a suitable and appropriate choice of damping ratio develops the accelerometer parameters and enhances the vibratory analysis technique

Ghemari Zine, Saad Salah. (2019), Defects Diagnosis by Vibration Analysis and Improvement of Vibration Sensor Measurement Accuracy. Sensor Letters : American Scientific Publishers, https://www.ingentaconnect.com/content/asp/senlet/2019/00000017/00000008/art00005

Résumé: TThe rotating machines in operation generate vibrations because of dynamic elements movements. In order to evaluate and monitor these vibratory movements a measurement chain with an electronic device called a vibration sensor (accelerometer) is required to transform the mechanical load or the vibratory movement force into a temporal electrical signal. In addition, the Fast Fourier Transform Spectrum Analyzer is used to convert this signal to a frequency electrical signal (the vibratory level). The main issue of the vibration sensor is the measurement accuracy of the vibratory level. In order to overcome this problem, the vibration sensor is modeled, simulated and an appropriate choice of damping rate is made to improve the sensor performances. This choice makes possible the accuracy optimization, the measurement error minimization and improves the sensor sensitivity. Finally a new sensor design that increases the accuracy is proposed. This improvement progresses the vibratory analysis technique thus to detect the defects in an early stage.

Abdelmalik Bendaikha, Salah Saad, Abdelhak Abdou, Mabrouk Defdaf, Yahia Laamari . (2019), A Study of SVM-DTC and Conventional DTC for Induction Motors Drive Fed by Five-level Inverter. European Journal of Electrical Engineering : Lavoisier, http://www.iieta.org/journals/ejee/paper/10.18280/ejee.210113

Résumé: In order to reduce torque and flux fluctuations as well as harmonic currents distortion, two models were developed, the first is based on conventional DTC and the second is based on the SVM-DTC, controlling induction motor fed by a Five-level inverter. PI controller is employed for flux and torque control in order to obtain reference voltages Vd and Vq that will be used in the SVM algorithm. The developed models were validated by simulation tests and the obtained results have showed the advantages of DTC-SVM control over conventional DTC in harmonic currents distortion, torque and flux fluctuations reductions

Fares Zaamouche, Salah Saad, Larbi Hamiche. (2019), A Discontinuous PWM Techniques Evaluation by Analysis of Voltage and Current Waveforms . The International Journal of Scientific Research & Engineering Technology http://ipco-co.com/IJSET/vol7/issue-2/ACECS-43.pdf

Résumé: In this paper experimental and simulation results of three phase voltage source inverter (3P-VSI) controlled by a discontinuous pulse width modulation technique (DPWM) are presented. This technique is proposed to overcome the disadvantages of the space vector pulse width modulation (SVPWM) mainly high modulation frequency and increased inverter switching losses. This control strategy is a simple and an easy technique generating the same switching pattern as space vector modulation with less switching losses and reduced total harmonic distortion. The main motivation of the present paper is that the DPWM is not largely and deeply investigated and can present a serious alternative to other PWM techniques. The obtained results have showed that with DPWM technique, switching losses and total harmonic distortion (THD) are reduced. Furthermore, the implementations of this technique in a dSPACE (DS1104) controller are discussed and analyzed.

2018
Ghemari Zine, Saad Salah. (2018), Piezoresistive Accelerometer Mathematical Model Development With Experimental Validation . IEEE Sensors Journal (USA), (2018), 18 (7), pp 2690-2696. : IEEE, https://ieeexplore.ieee.org/document/8290924

Résumé: This paper is mainly focused on piezoresistive accelerometer performance improvement. Thus a new model of this sensor is derived to enhance its various parameters, such as precision, sensitivity, and reliability. Moreover, applying this model, a new design of piezoresistive accelerometer can be achieved. The developed model is validated by simulations and confirmed by experimental tests to verify its effectiveness in industrial applications. The comparison study showed that the best choice of damping rate to reduce the measurement error and increase the precision corresponds to the rate chosen in this paper. The results have also demonstrated that a more reliable sensor can be designed compared with the existing designs.

Chouaf Fethi, Saad Salah. (2018), A New Structure of Nine Level Inverter Used as Active Power Filter . International Journal of Power Electronics and Drive Systems (IJPEDS) : Institute of Advanced Engineering and Science (IAES), Fethi Chouaf, Salah Saad/links/5b6c14ed92851ca65053b3cb/A-new-structure-of-the-nine-level-inverter-used-as-active-power-filter-with-a-reduced-number-of-swiches.pdf

Résumé: In the scope of this work, a new structure of the nine level inverter is proposed using a reduced number of power switches. This inverter is used as a shunt active power filter to compensate harmonic currents and the reactive power. The modeling and simulation of the proposed model were carried out in Matlab/Simulink environment. The simulation results show that the filtering performances were achieved despite the reduction of the switches number. It was found that the current waveform becomes purely sinusoidal with a reduction in the harmonic distortion rate (THD) to 2.68%. This implies good compensation of both harmonics and reactive power with a power factor closer to unity. Reducing the switches number allows reducing the switching losses and lowering the duration of the applied voltage supported by the semiconductors. The proposed topology also allows to get simple structure of the inverter with a reduced cost.

(2018), Resonance Effect Decrease and Accuracy Increase of Piezoelectric Accelerometer Measurement. Shock and Vibration : Hindawi, https://www.hindawi.com/journals/sv/2018/5370438/abs/

Résumé: A suitable piezoelectric accelerometer mathematical model is proposed to extract a relationship of motion relative frequency as a function of natural frequency. This relationship helps to select appropriate accelerometer frequency range that minimizes measurement error and improves accuracy. It also allows deducing a formula relating the damping rate and the measurement error of the accelerometer. To protect the accelerometer from failure, the resonance phenomenon effect must be minimized. In order to achieve this objective, physical principle is modeled to find a precise relationship which can determine the accelerometer appropriate frequency range. The developed model was simulated and the obtained results have showed that the selection of the frequency range has minimized the measurement error, increased the accelerometer accuracy, and reduced the resonance effect. Finally a comparative study was conducted to show the importance of the obtained results compared to recent literatures.

(2018), A Bayesian Information System for Predicting Stator Faults in Induction Machines. Acta Universitatis Sapientiae, Electrical and Mechanical Engineeringhttps://www.researchgate.net/publication/330879960

Résumé: The approach adopted in this paper focuses on the faults prediction in asynchronous machines. The main goal is to explore interesting information regarding the diagnosis and prediction of electrical machines failures by the use of a Bayesian graphical model. The Bayesian forecasting model developed in this paper provides a posteriori probability for faults in each hierarchical level related to the breakdowns process. It has the advantage that it can give needed information’s for maintenance planning. A real industrial case study is presented in which the maintenance staff expertise has been used to identify the structure of the Bayesian network and completed by the parameters definition of the Bayesian network using historical file data of an induction motor. The robustness of the proposed methodology has also been tested. The results showed that the Bayesian network can be used for safety, reliability and planning applications.

2017
(2017), Direct neural method for harmonic currents estimation using adaptive linear element . (Elsevier) Electric Power Systems Research (Netherlands) : Elsevier, https://www.sciencedirect.com/science/article/abs/pii/S0378779617302675

Résumé: The use of nonlinear loads has increased in power systems consequently the harmonic currents have also increased causing detrimental effects to the supply system and user equipment. The aim of the present paper is to identify harmonics in order to obtain a perfect compensation by active power filter (APF). A study of harmonic currents identification by two different methods is conducted in this work. The instantaneous power (PQ) theory method requires two low-pass filters for the extraction of direct power components from total power components. However the direct neural method based on ADALINE neural network method estimates total harmonic current as well as harmonic components separately. Moreover, the identification of each component separately enables the selective compensation of harmonics by the active filter if the objective is to minimize the cost. The method is easy to implement in real time …

(2017), Parameters improvement and suggestion of new design of capacitive accelerometer. Analog Integrated Circuits and Signal Processing : Springer USA, https://link.springer.com/article/10.1007/s10470-017-0970-y

Résumé: The capacitance variation of capacitive accelerometer as a function of vibratory movement relative frequency is presented using a developed model validated by simulation and experimental tests. The damping rate effect on accelerometer capacitance variation is studied for four damping rate values. The first value is that of accelerometer used in the experimental tests, the second and third are taken from the recent works and the fourth is the value proposed in this work. A comparative study has been made to mount our improvements on the capacitive accelerometer performances by the comparison between the proposed accelerometers in the recent works. Finally, a new capacitive accelerometer with improved parameters is proposed having many benefits over the existing accelerometers. These benefits are: appropriate choice of damping rate (equal to 0.68), very low measurement error

(2017), New formula for the piezoresistive accelerometer motion acceleration and experimental validation. Journal of Advanced Manufacturing Systems : World Scientific Publishing Company, https://www.worldscientific.com/doi/abs/10.1142/S0219686717500044

Résumé: A piezoresistive accelerometer is the first element of a vibration measurement chain, and its improvement can enhance measurement quality. In this paper, we have developed a new formula that links the movement acceleration as a function of the natural frequency and the damping rate of the piezoresistive accelerometer in first time, and movement acceleration as a function of the measurement error in second time. This model allows the decrease of the acceleration measurement error and increases the accelerometer accuracy by choosing the right damping rate and frequency range. Finally, this new formula allows proposing new parameters for more accurate and reliable piezoresistive accelerometer

(2017), Sensorless control of inverter dc-bus voltage combined with modified PQ control using extended KF. Electrical Engineering : Springer Berlin Heidelberg, https://link.springer.com/article/10.1007/s00202-016-0415-0

Résumé: this paper presents a sensorless control approach of inverter dc-bus voltage using extended Kalman Filter (EKF). A positive sequence detection of grid voltage and load current is also proposed. The dc-bus voltage estimated by EKF is combined with the modified instantaneous power (p–q) control technique for photovoltaic system application to improve electrical energy quality at the grid under photovoltaic (PV) varying temperature and radiation and also distorted grid voltage ensuring at the same time the supply of unbalanced nonlinear load. The ac grid receives the required active power from the PV cells through boost converter, dc-bus and inverter. It supplies the energy to unbalanced nonlinear load in case of absence of PV energy. The boost converter control extracts the maximum power point from PV cells by Disturb and Observe (P&O) algorithm. Mathematical relationships of different parts of PV system are described and studied. The control system is simulated using the SimPower blockset of Matlab/Simulink. Simulation results have showed that the proposed methodology is an efficient solution to PV control system.

(2017), Comparative Study of Five-Level and Seven-Level Inverter Controlled by SVPWM. International Journal of Power Electronics and Drive Systems (IJPEDS) https://scholar.google.com/scholar?cluster=8452754277064766738&hl=en&oi=scholarr

Résumé: This paper presents a MATLAB/SIMULINK model of two multi-level inverter topologies. Algorithms based on space vector modulation (SVM) technique are developed in order to conduct a comparative study on diode clamped five and seven level inverters. The scheme used to develop these control algorithms are based on symmetrical sequence because of the symmetry of the switching wave. Both topologies are simulated and analyzed using a squirrel cage induction motor. The results have showed that the best motor dynamic response with less harmonic distortion and torque fluctuations is obtained when seven-level inverter is employed.

(2017), Improvement of Method Queues by Progress of the Piezoresistive Accelerometer Parameters. Journal of Advanced Manufacturing Systems : World Scientific Publishing Company, https://www.worldscientific.com/doi/abs/10.1142/S0219686717500147

Résumé: n this paper the queues are used as a method to improve maintenance performance. The information collected by vibration analysis is used to check the system status and see whether a maintenance operation is to be organized. Thus, for a precise decision, the improvement of accelerometer parameters is required. In order to solve this issue, the piezoresistive accelerometer step and impulse responses are enhanced by using appropriate parameters (damping rate and frequency range). Computer simulation tests were conducted to confirm this approach. The obtained results have shown the difference between the accelerometer with the proposed parameters and the accelerometer used in the experiment. It can be concluded that the proposed parameters provide stable and accurate accelerometer.

(2017), Direct Torque Control of Induction Motor Fed by Three-level Inverter Using Fuzzy Logic. AMSE JOURNALS-AMSE IIETA publication-2017 : AMSE IIETA publication, https://www.researchgate.net/profile/Chebabhi_Ali/publication/

Résumé: The present paper describes the direct torque sensor less speed control of induction motor fed by three-level voltage source inverter. Inverter switches control is based on fuzzy logic control. Compared to conventional direct torque control (DTC), hysteresis controllers, flux position and voltage vector selection table are replaced by fuzzy logic blocks to realize a DTC-fuzzy control. The obtained results have showed high speed performance, reduced torque and flux fluctuations when the proposed DTC-fuzzy strategy is used for the control of three-level voltage source inverter associated with induction machine.

(2017), Simulation and Experimental Validation of New Model for the Piezoresistive Accelerometer. Sensor Letters : American Scientific Publishers, https://www.ingentaconnect.com/contentone/asp/senlet/2017/00000015/00000002/art00005

Résumé: In the present paper a new model of piezoresistive accelerometer is proposed in order to enhance its operation performances. The main task of this accelerometer is to measure dynamic systems vibrations and is generally placed at the most mobile point in the system. In this work, a model relating the piezoresistive accelerometer displacement as a function of the measurement error is developed. The validation of this model is conducted by a series of experimental tests based on a measurement setup consisting from an electrodynamics exciter, a vibration sensor, an amplifier and an FFT analyzer. The new model can improve greatly the performance of the vibration sensor by improving measurement precision, sensitivity and reliability, making the sensor more efficient.

2016
(2016), Simulation and Experimentation of Voltage Source Inverter (VSI) for a Photovoltaic System. ELECTROTEHNICĂ, ELECTRONICĂ, AUTOMATICĂ (EEA) : Institutul de Cercetare si Proiectare pentru Electrotehnica, https://www.scimagojr.com/journalsearch.php?q=21100255070&tip=sid&clean=0

Résumé: In this paper, the simulation and real time implementation of a space vector pulse-width modulation (SVPWM) control scheme to demonstrate the high performance of the photovoltaic inverter. The design and the simulation of electric operation of a photovoltaic (PV) system controlled by an intelligent method enabling to track the maximum power produced by the photovoltaic generator are described. The simulation was performed in the Simulink/MATLAB environment and the PV output voltage is represented by a dc power supply of the inverter. Furthermore, tests are performed on experimental platform to implement the developed algorithms of SVPWM inverter used to convert the produced dc voltage to a variable ac voltage. The experimental waveforms such as ac output voltages, current and total harmonic distortion are presented and analysed.

(2016), Diagnosis and detection of short circuit in asynchronous motor using three-phase model. International Journal of System Assurance Engineering and Management : Springer, https://link.springer.com/article/10.1007/s13198-016-0435-1

Résumé: Several reported works have studied detection and short circuit fault diagnosis in electric machines based on different models. Regarding simplifying assumptions and model conditions of use in relation to stator fault (short circuit), the X change model is proposed because all parameters are computed online. Subsequently, the electrical parameters do not depend on relative position between the stator and the rotor. In this paper, two signal processing techniques are employed for short-circuit diagnosis. The first technique is based on spectral analysis (FFT) using stator current spectral components in healthy and short circuit states at steady state (stationary state). Whereas, the second technique is based on discrete wavelet transform (DWT) considered as an ideal tool because of its signals (non stationary state) analysis ability. Tests are conducted by numerical simulation and the obtained results have showed clearly that, the signatures can be extracted to detect and locate faults.

(2016), SVM technique based on DTC sensorless control optimized by ANN applied to a double stator AM. The Mediterranean Journal of Measurement and Controlhttps://www.researchgate.net/profile/Chebabhi_Ali/publication/

Résumé: The present paper is focused on Direct Torque Control (DTC) Speed Sensorless of a double stator asynchronous machine (DSAM) fed by three-level six-phase inverter. The inverter switches control is based on Space Vector Modulation technique optimized by Artificial Neuronal Network (SVMANN). Compared to the conventional DTC technique, voltage vectors selection table is replaced by space vector modulation technique to realize a DTC-SVM speed sensorless control. Moreover, to validate the proposed control technique several tests were conducted by computer simulations. The obtained results have showed high speed performances and a reduction in torque and flux fluctuations compared to other techniques (DTC and DTC-SVM) when the proposed DTC-SVM-ANN control technique is applied to control a double stator asynchronous machine fed by a three-level six-phase inverter.

2015
(2015), New model of piezoelectric accelerometer relative movement modulus. Transactions of the Institute of Measurement and Control : SAGE Publications, https://journals.sagepub.com/doi/abs/10.1177/0142331214549572

Résumé: A piezoelectric accelerometer is the first element of a vibration measurement chain, and its improvement can enhance measurement quality. In this work, a new model of relative movement modulus as a function of measurement error is developed, thus minimizing the measurement error and increasing the measurement precision of the accelerometer. Therefore, a precise relationship between the movement relative frequency and the piezoelectric accelerometer natural frequency is extracted in order to determine a good frequency range relative to the piezoelectric accelerometer. Thus, the failure risk of the resonance phenomenon is minimized and the accelerometer piezoelectric reliability is optimized. The developed model is confirmed and validated by experimental tests. The purpose and the objective of this work is to improve the performance and the design of the accelerometer.

(2015), Hysteresis control for shunt active power filter under unbalanced three-phase load conditions. Journal of Electrical and Computer Engineering : Hindawi Publishing Corp, https://www.hindawi.com/journals/jece/2015/391040/

Résumé: This paper focuses on a four-wire shunt active power filter (APF) control scheme proposed to improve the performance of the APF. This filter is used to compensate harmonic distortion in three-phase four-wire systems. Several harmonic suppression techniques have been widely proposed and applied to minimize harmonic effects. The proposed control scheme can compensate harmonics and reactive power of the nonlinear loads simultaneously. This approach is compared to the conventional shunt APF reference compensation strategy. The developed algorithm is validated by simulation tests using MATLAB Simulink. The obtained results have demonstrated the effectiveness of the proposed scheme and confirmed the theoretical developments for balanced and unbalanced nonlinear loads

(2015), Pipelines Reliability Analysis Under Corrosion Effect and Residual Stress. Arabian Journal for Science and Engineering : Springer Berlin Heidelberg, https://link.springer.com/article/10.1007/s13369-015-1723-9

Résumé: This work focuses on a development of a finite element model that simulates corrosion phenomenon and its influence on structure rupture (pipelines). Subsequently, the pitting effect on reliability and pipelines lifetime is studied. In this paper, the investigated structure material is characterized experimentally, in order to determine the maximum strength and stress resistance. Therefore, a numerical model was developed under ANSYS code to simulate different loads to obtain the stress concentration factor as the stresses could surpass the yielding limit in the corrosion impact, and to determine the Von Mises stress. A corrosion model and residual stresses used in the literature are coupled with the probabilistic model to find the limit state function. Thus, failure probability and structure reliability index under the effect of pitting corrosion phenomena are calculated and the obtained results are discussed and analyzed.

(2015), Comparative Study between Direct Torque Control and Sliding Mode Control of Sensorless IM. International Journal of Mechanical and Mechatronics Engineering : World Academy of Science, Engineering and Technology, https://scholar.google.com/citations?user=_x9MWRIAAAAJ&hl
2014
(2014), Reducing the Measurement Error to Optimize the Sensitivity of the Vibration Sensor. EEE Sensors Journal : IEEE, https://ieeexplore.ieee.org/abstract/document/6704719

Résumé: This paper is focused on the reduction of measurement error to obtain a high sensitive sensor. A mathematical model related to mechanical sensitivity is developed as a function of measurement error. This model can improve the measured value (indicated by the vibration sensor) as close as possible to the real value. To achieve this objective, the damping rate is enhanced by making the appropriate choice to reduce and limit the measurement error to a minimum (1%), to increase the measurement accuracy to 99%, and to minimize the uncertainty of the mechanical sensitivity of the vibration sensor to 0.5%. Therefore, in this paper, several parameters are improved and a new accurate, reliable, and sensitive vibration sensor is proposed.

(2014), Rapid transaction to load variations of active filter supplied by PV system. Frontiers in energy : Springer, https://link.springer.com/article/10.1007/s11708-014-0325-7

Résumé: This paper deals with the analysis and control of a photovoltaic (PV) system connected to the main supply through a Boost converter and shunt active filter supplied by a PV system providing continuous supply of nonlinear load in variation. A robust control of a PV system connected to the grid while feeding a variable nonlinear load is developed and highlighted. This development is based on the control of the Boost converter to extract the maximum power from the PV system using the Perturb and Observe (P and O) algorithm in the presence of temperature and illumination. The proposed modeling and control strategy provide power to the variable nonlinear load and facilitates the transfer of power from solar panel to the grid while improving the quality of energy (harmonic currents compensation, power factor compensation and dc bus voltage regulation). Validation of the developed model and control

(2014), Reducing the measurement error to optimize the sensitivity of the vibration sensor. IEEE Sensors Journal : IEEE, https://ieeexplore.ieee.org/abstract/document/6704719

Résumé: This paper is focused on the reduction of measurement error to obtain a high sensitive sensor. A mathematical model related to mechanical sensitivity is developed as a function of measurement error. This model can improve the measured value (indicated by the vibration sensor) as close as possible to the real value. To achieve this objective, the damping rate is enhanced by making the appropriate choice to reduce and limit the measurement error to a minimum (1%), to increase the measurement accuracy to 99%, and to minimize the uncertainty of the mechanical sensitivity of the vibration sensor to 0.5%. Therefore, in this paper, several parameters are improved and a new accurate, reliable, and sensitive vibration sensor is proposed.

(2014), A comparative study of various methods of gear faults diagnosis. Journal of Failure Analysis and Prevention : Springer US, https://link.springer.com/article/10.1007/s11668-014-9860-0

Résumé: Investigating gear damages using vibration signal is a subject of a high interest, because gears vibration signals are complex and difficult to understand. A failure diagnosis of gearbox based on Fourier analysis of the vibration produced by speed reducers has shown its limits in terms of spectral resolution. In the present paper, a comparative study of the performances of various different methods of fault diagnosis of helicopter gearbox gear is carried out. The results are highlighted on the basis of real data recorded during a helicopter flight and have showed that cepstral analysis is most effective technique in detecting gearbox gear faults.

2013
(2013), A comparative study of harmonic currents extraction by simulation and implementation. International Journal of Electrical Power & Energy Systems : elsevier, https://www.sciencedirect.com/science/article/pii/S0142061513001956

Résumé: The aim of the present work is to obtain a perfect compensation by extracting accurate harmonic currents. The objective is to avoid the consequences due to the presence of disturbances in the power system. A comparative study of harmonic currents extraction by simulation and implementation is carried out for two different techniques. The first technique is based on the instantaneous powers, taking advantage of the relationship between current and the power transformed from the supply source to the loads. The second is based on ADALINE neural network. The neural method can estimate the harmonic terms individually and online, therefore, the APF can realise a selective compensation. The developed architectures are validated by computer simulation and experimental tests. The algorithms are implemented in the dSPACE Board in order to show the effectiveness and capability of each technique. The results have demonstrated that the speed and the accuracy of the ADALINE can improve greatly the performances of active power filters.

(2013), Adaptive fault diagnosis in rotating machines using indicators selection. Mechanical Systems and Signal Processing : Elsevier, https://www.sciencedirect.com/science/article/pii/S0888327013003129

Résumé: Over the past two decades, condition monitoring and faults diagnosis in rotating machinery have been widely studied and reported. In the present paper an algorithm for fault diagnosis in industrial rotating machines facing new operating conditions emergence is developed on the basis of input indicators, extracted from vibrations spectrums. Indicators selection is used to improve diagnosis performances by the help of a hybrid approach using several selection criteria and different classifiers. To validate the performances of this algorithm, experimental tests were conducted on two industrial systems with various operating conditions. The results have proved the effectiveness of the developed algorithm compared to the “J48 decision tree” and also reveal the need to re-select the indicators for reliable monitoring of working conditions

2012
(2012), Development of measurement precision of sensor vibration. Journal of Vibration and Control : SAGE Publications, https://journals.sagepub.com/doi/abs/10.1177/1077546312445595

Résumé: In this paper, an accelerometer mathematical model is developed and simulated to choose the best damping rate value to limit the measurement error to 1%. Using this model, the equations of relative movement modulus and measurement error with respect to damping rate and frequency ratio can be determined. The developed model is validated by a series of tests carried out by computer simulation. The obtained results have shown that a suitable damping rate can minimize the measurement error of relative movement to 1 %. The presented model is a useful tool to improve the damping rate and measurement precision of the accelerometer.

(2012), Development of model and enhancement of measurement precision of sensor vibration. IEEE sensors journals : IEEE, https://ieeexplore.ieee.org/abstract/document/6253225

Résumé: In this paper, research on a vibration sensor (accelerometer) that converts mechanical load to an electrical signal is carried out. An accelerometer mathematical model is developed to select the best damping rate value to reduce the measurement error as much as possible. The main purpose of this paper is to enhance the vibration sensor performances (choice of the best value of damping rate and minimization of measurement error by increasing sensor precision and reliability). The developed model is validated by computer simulation and experimental tests. The obtained results have demonstrated that an appropriate damping rate can reduce measurement error of relative movement to 1%.

(2012), Fuzzy Logic Controller forThree-level Series Active Power Filter to Compensate Voltage Harmonics. JEE.ROhttp://www.jee.ro/covers/editions.php?act=front&issue_id=IB1387812522I52b856aaa8b13

Résumé: In this paper, the three-level inverter is used as a series active power filter to suppress harmonic voltage drawn from a nonlinear load. This filter acts as zero impedance for the fundamental frequency and as high resistor for harmonic frequencies. Most previously reported three-phase series active power filters are based on two-level inverters with conventional controllers requiring a complex and a complicated mathematical model. To overcome this problem a fuzzy logic controller is used and extended to a three level series active power filter. This work presents principles of operation and design of a fuzzy logic controller algorithm to control the harmonic voltages. The viability of the proposed algorithm is validated with computer simulation. The obtained results showed that source voltage is sinusoidal and in phase with source current as well as a reduced total harmonic distortion.

2009
(2009), Fuzzy logic controller for three-level shunt active filter compensating harmonics and reactive power. Electric Power Systems Research : Elsevier, https://www.sciencedirect.com/science/article/abs/pii/S0378779609000923

Résumé: In this paper, the three-level inverter is used as a shunt active power filter, making use of the multilevel inverter advantages of low harmonic distortion, and reduced switching losses. This PWM inverter is employed as shunt APF compensating reactive power and suppresses harmonics drawn from a nonlinear load. Most previously reported three-phase active power filters are based on two-level inverters with conventional controllers requiring a complex and a complicated mathematical model. In order to overcome this problem a fuzzy logic controller applied and extended to a three level shunt APF is proposed. In this paper, fuzzy logic control algorithm is proposed for harmonic current and inverter dc voltage control to improve the performances of the three levels active power filters. The MATLAB Fuzzy Logic Toolbox is used for implementing the fuzzy logic control algorithm. The obtained results showed that, the proposed shunt active power filter controller have produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

(2009), Mechanical surface treatment of steel-Optimization parameters of regime. Physics Procedia : Elsevier, https://www.sciencedirect.com/science/article/pii/S1875389209001679

Résumé: Mechanical treatment process by superficial plastic deformation is employed for finished mechanical part surface. It introduces structural modifications that offer to basic material new properties witch give a high quality of physical and geometrical on superficial layers. This study focuses on the application of burnishing treatment (ball burnishing) on XC48 steel and parameters optimisation of treatment regime. Three important parameters were considered: burnishing force “ Py”, burnishing feed “f” and ball radius “r”. An empirical model has been developed to illustrate the relationship between these parameters and superficial layer characteristics defined by surface roughness “ Ra” and superficial hardness “ Hv”. A program was developed in order to determine the optimum treatment regimes for each characteristic.

2008
(2008), Sensitive membranes in solution with electrochemical impedance spectroscopy . Materials Science and Engineering: C : Elsevier, https://www.sciencedirect.com/science/article/pii/S0928493107002378

Résumé: The electrochemical impedance spectroscopy is used to study the behaviour of a CWE electrode modified with a thin layer of polymeric membrane, in order to detect ammonium ions in solution. This membrane involves the incorporation of a zeolite type ionophore (clinoptilolite) into a polymer (polyvinyl chloride), and a plasticizing agent (dioctylphtalate). The ionic exchanges are characterized using electrochemical impedance spectroscopy. The CWE shows a good sensitivity and a low detection limit of about 10− 8 M.

2007
(2007), Shunt active power filter for current harmonics suppression using hysteresis control. Asian Journal of Information Technology http://docsdrive.com/pdfs/medwelljournals/ajit/2007/436-440.pdf

Résumé: This study presents a simulation of a shunt active power filter for the suppression of current harmonics generated by a three-phase diodes rectifier converter. The shunt active power filter is a voltage source inverter using hysteresis control. To ensure the self adaptation of the active filter with the changes of the load a continuous diagram of regulation of the voltage and current injected are carried out. The results obtained by simulation gave good results to the levels of the reduction of the harmonics. The harmonic rate of distortion to calculate after filtering is lower than 5%, which is less than the international recommendations and standards.

(2007), Influence of solid particles on centrifugal pump characteristics. Journal of Engineering and Application Scienceshttp://docsdrive.com/pdfs/medwelljournals/jeasci/2007/244-247.pdf

Résumé: In this work the influence of solid particles on centrifugal pump is presented. The solid used is slurry of washed phosphate having a density of 2800 kg m-3 and a maximum solid particles diameter of 3 mm. The tests are carried out with a metal impeller pump having 6 blades. The obtained results are compared with those available in the literature and recommendations are proposed to recalculate centrifugal characteristics of pumps functioning in mixture.

(2007), Stability analysis of simultaneous speed and stator resistance estimation . International Review of Electrical Engineering https://scholar.google.com/scholar?hl=en&as_sdt=0,5&cluster=8347053389908739142
(2007), Transducer (Accelerometer) Modeling and Simulation. Asian J. Inform. Techhttp://docsdrive.com/pdfs/medwelljournals/ajit/2007/54-57.pdf

Résumé: In this research the accelerometer is modelled and simulated in order to choose the accelerometer corresponding to the vibration generated by the machine. A mathematical model of the accelerometer and a program of simulation working in MATLAB environment are proposed. This simulation enables to calculate the relative movement modulus, the measurement errors, damping ratio and also the choice of the accelerometer frequency band. The results obtained are discussed and can make easier the choice of the accelerometer that suits the vibration generated by the machine

(2007), Design of a haulage system operating on a downward curvilinear track. Journal of Engineering and applied sciences : Medwell, https://medwelljournals.com/abstract/?doi=jeasci.2007.81.85

Résumé: One of the most important problems met in cable downward installations is the considerable unbalance between tensions of two cable bits caused by load variation. This variation mainly caused by downward cable bit mass which induces amplitude in torque variation applied to control group. To maintain skip speed in recommended limits and limit the motor drive power as well as operation mode, dynamic balancing of downward system is carried out. This system acts as to limit the difference between tensions of the two downward system cable bits. In this study, it is recommended the application of downward track having a variable slope angle to realise a dynamic balancing system. Thus, because of track curvilinear shape, the decomposition of forces acting on each cable bit is such that to realize tensions equality between the two cable bits. The other advantage of this balancing type is the application of a constant braking torque which is an important factor for the choice and rational use of control group.

(2007), Simulation for Obtaining Mild Steels from a Cast Iron Rich in Manganese. Asian Journal of Information Technology : Medwell, http://medwelljournals.com/abstract/?doi=ajit.2007.1196.1199

Résumé: The converter is a reactor which can eliminate to a very low rate oxydable elements from the cast iron (C, Mn�). However, in spite of great progress having allowed a better approach of physical and chemical balances, the results obtained remain inefficient. The quality from the chemical point of view of the cast iron is one of the main causes of this dispersion. It is currently the case of oxygen steel-works of Arcelor-Mittal-Annaba-Algeria, which have enormous difficulties in producing tinplate from a cast iron very rich in Manganese, around 2.36%. In fact 42% of the fusions elaborated with oxygen steel-works their concentration in Manganese at the end of the blowing is higher than that of the concerned steel and thus, have to be subjected to an additional blowing. This operation involves an increase in production cycle (approximately 7 mn) leading to a significant loss of production. The conditions of oxidation of carbon, the temperature of the bath, the alkalinity of the slag and particularly the initial content of Manganese in the cast iron, have a direct influence on the residual Manganese content in steel. In order to improve the working conditions of the steel-works, it is proposed in this work to carry out partial demanganization of the cast iron outside the reactor using the process of the gas-lift. In the first step of this study, a gas-lift experimental set up is designed containing air compression machine, a column to rise of the Gas-liquid mixture and various control devices as well as a complete procedure of experimentation is developed. This experimental set up has made possible the simulation at the laboratory the conditions of the cast iron treatment. The analysis of the obtained results have allowed the establishment hus of the relation: liquid flow and gas-flow. Finally, the design characteristics of the industrial plant were fixed and a calculation model is established in order to determine the procedure which allows easy and fast extension of the model for each cast iron chemical composition.

(2007), Obtaining and Observation of Bent Sub-Boundaries in the TiO Rutile 2. Asian Journal of Information Technology : Medwell, http://docsdrive.com/pdfs/medwelljournals/ajit/2007/102-104.pdf

Résumé: This research concerns the study of mechanical behaviour of this material at high temperature. It is a question of observing dislocations microstructure in monocrystaline rutile by Tranmission Electronic Microscope (T.E.M.). This investigation method requires very thin foils, cut out in deformed sample. Thus it is necessary to develop a method to obtain an important dislocation density in restricted zone of the sample. The solution is to obtain three points bent sub-boundaries. For this purpose the chosen solution consists to stir only one slip system and then proceed to a polygonization.The slip system to stir is of the type {101}<î 01>. From a rutile monocrystal, samples have been cut, suitably oriented using X rays by laue method. After mechanical polishing, samples have ben strained in three points bent at 1000�C then annealed at 1300�C during 12 h. The sub-boundaries were observed by optical microscope by eth-pits which consists to chemical polishing by alkaline fusion in KOH followed by an immersion in boiling sulphuric acid during 2 to3 min. It is sub-boundaries of very weak disorientation. Practically all concentrates in central zone of the sample. The rutile being a ceramic chemically weak stired, thin foils have been obtained by ionic bombardment thinning method. The T.E.M. observation have allowed to characterize the dislocations forming the sub-boundaries corresponding to dislocations arrangement of corner type, located in the same plan.

2006
(2006), Harmonics Suppression and Reactive Power Compensation . Asian Journal of Information Technologyhttps://www.researchgate.net/profile/Amar_Omeiri/publication
(2006), Experimental investigation on surface potential Kinetics potential polyethylene terephtalate (PET). Journal of Engineering and applied sciences : Medwell, http://docsdrive.com/pdfs/medwelljournals/jeasci/2006/329-334.pdf
2004
S. Saad, L. Herous, N. Doghmane & A. Lachouri . (2004), The research of shunt active power filter based on DSP.. Information Technology Journal : orgz, https://link.springer.com/article/10.1007/BF03325562

Résumé: When the load and system parameters are changing, the APF usually appears unstable and its exact mathematical model is quite difficult to determine. This study is to introduce Takagi Sugeno (TS) type fuzzy controller and Lyapunov-based stability theory into the Direct Current (DC) side voltage control and current control of the three-phase Active Power Filter (APF), aiming to guarantee the precision and stability of APF. Firstly, the TS fuzzy control is applied to voltage error and error rate at DC side to attain the source current amplitude of reference value; then the Lyapunov method is adopted to design the switching function of APF and the global stability of control system is ensured by insuring the derivative of energy-like Lyapunov function always negative. The parameters of TS fuzzy controller are optimized by using Adaptive Neuro-Fuzzy Inference System (ANFIS) in Matlab/Simulink. As the results of comparative …

1999
(1999), A Laboratory Study of Rock Acoustic Characteristics by Parametric Spectral Estimation. Acta Geodaetica and Geophysica Hungarica : Springer Netherlands, https://link.springer.com/article/

Résumé: In this paper, a new approach on nondestructive evaluation by ultrasonic signal is proposed. This work is based on a qualitative analysis (parametric method) of rock acoustic characteristics by autoregressive (AR) spectral estimation of ultrasonic signals transmitted through materials (rock samples). The longitudinal waves (P) are chosen in the experiment analysis (the case of transversal waves (5) will be tested in other studies).

Publications nationales

2018
(2018), Adaline Neural Network and Real-Imaginary Instantaneous Powers Method for Harmonic Identification. Synthèse: Revue des Sciences et de la Technologie : Université Badji Mokhtar-Annaba, https://www.ajol.info/index.php/srst/article/view/172539

Résumé: In this paper, a shunt active power filter (SAPF) is used for reactive power compensation and harmonic current suppression. Algorithm based on (ADALINE) Neural Network and Real and Imaginary Instantaneous Powers (ANN-RIIP) is developed in order to estimate and identify the harmonic terms individually and online. This algorithm is simulated in MATLAB/Simulink environment and implemented experimental in a dSPACE 1104 controller. The results obtained by simulation are in agreement with the experimental results confirming the effectiveness of the proposed ANN-RIIP algorithm. The results have also demonstrated that the speed and accuracy of ADALINE can improve the performances of active power filters.

2017
(2017), Simulation and experimental tests of a real-time DPWM technique for the control of VSI-IM Drive. Synthèse: Revue des Sciences et de la Technologie : Université Badji Mokhtar-Annaba, https://www.ajol.info/index.php/srst/article/view/157263

Résumé: In the present paper experimental and simulation results of three phase voltage source inverter (3P-VSI) controlled by the strategy called discontinuous pulse width modulation technique (DPWM_3) corresponding to four saturation of 30° are presented. This technique is proposed to overcome the disadvantages of the space vector pulse width modulation (SVPWM) mainly high modulation frequency and increased inverter switching losses. This control strategy is a simple and an easy technique generating the same switching pattern as space vector modulation with less switching losses and reduced total harmonic distortion. The main motivation of the present paper is that the DPWM is not largely and deeply investigated and can present a serious alternative to other PWM techniques. The obtained results have showed that with DPWM technique, switching losses and total harmonic distortion (THD) are reduced. Furthermore, the implementations of this technique in a dSPACE (DS1104) controller is discussed and analyzed.

2008
(2008), Etude de l’auto-adaptivité du filtre actif parallèle aux variations de la charge. Synthèse: Revue des Sciences et de la Technologie : Université Badji Mokhtar-Annaba, https://www.ajol.info/index.php/srst/article/view/117863

Résumé: Cet article s’ intéresse à l’amélioration des performances du filtre actif parallèle pour s’ adapter d’une manière automatique aux variations de la charge. Ce filtre est un onduleur de tension à MLI destiné à éliminer les harmoniques de courant générés par un pont redresseur triphasé non commandé (charge non linéaire). Pour assurer l’auto-additivité du filtre aux variations de la charge, deux schémas de régulation à base du régulateur P sont proposés, l’un pour la tension continue et l’autre pour le courant injecté. Les résultats obtenus par simulation ont montrés une amélioration des performances de ce filtre. Le taux de distorsion harmonique (THD) calculé après filtrage est inférieur à 5% et le filtre s’ adapte parfaitement aux variations de la charge

2006
(2006), Correction du déséquilibre dynamique dans les installations de descentes à cable . revue synthèse n° 15 : Université Badji Mokhtar-Annaba, www.univ-annaba.org/.../instructions%20aux%20auteurs%20synth

Résumé: Un des problèmes essentiels rencontrés dans les installations de descente à câble est le déséquilibre considérable entre les tensions des deux brins du câble provoqué par la variation de la charge. Cette variation causée principalement par la masse du brin de câble descendent induit une amplitude dans la variation du couple appliqué au groupe de commande. Pour maintenir la vitesse du récipient dans les limites recommandées et limiter la puissance du moteur d'entrainement ainsi que son régime de fonctionnement, on réalise l'équilibrage dynamique du système de descente. il consiste à agir de manière à limiter la différence entre les tensions des deux brins du câble du système de descente. Dans cette article, on préconise l'application d'un tracé de descente à angle d'inclinaison variable pour la réalisation de l'équilibrage dynamique des systèmes de descente. Ainsi, grâce à la forme curviligne du tracé, la décomposition des forces agissant sur chaque brin du câble est telle qu'on réalise l'égalité des tensions entre les deux brins du câble. L'autre avantage de ce type d'équilibrage est l'application par la commande d'un couple résistant constant, ce qui constitue un facteur important pour le choix et l'utilisation rationnelle de la puissance de la commande.

2005
(2005), Compensation des courants harmoniques par le filtre actif parallèle . Revue Synthèse N°14 : Université Badji-Mokhtar, www.journals4free.com/link.jsp?l=43319395

Résumé: Ce travail présente une simulation d'un filtre actif parallèle de puissance pour la compensation des harmoniques de courants générés par un pont redresseur triphasé non commandé avec une inductance très élevée à sa sortie (un récepteur très polluant). Le filtre employé pour réduire les harmoniques de courants, est un onduleur de tension avec modulation de la largeur d'impulsion (MLI) connecté en parallèle au réseau électrique. La stratégie de commande du filtre est basée sur la théorie des puissances actives et réactives instantanées dite (p-q theory). Les résultats obtenus montrent une atténuation significative des harmoniques, ce qui met en évidence l'efficacité et les bonnes performances du filtre actif parallèle de puissance.

1999
(1999), Obtaining of Ti-Al alloy powder from Tio2-Al2o3 oxides by Ca or Mg co-reduction . Revue Synthèse N°5 : Université Badji Mokhtar-Annaba, synthese.univ-annaba.dz
1996
(1996), Détermination des propriétés acoustiques des roches par la méthode paramétrique . Revue Synthèse N°1 : Université Badji Mokhtar-Annaba, synthese.univ-annaba.dz/?p=7710
A LACHOURI, N DOGHMANE, S SAAD, L HEHOUS. (1996), Etude des propriétés acoustiques des roches par estimation spectrale. Synthèse : Université de Badji-Mokhtar Annaba, https://scholar.google.com/citations?view_op=view_citation&hl=en&user=_x9MWRIAAAAJ&cstart

Livres

1993
(1993), Eléments de base de théorie et de traitement du signal. Office des publications universitaires : Office des publications universitaires, https://scholar.google.com/scholar?cluster=8544072048514590248&hl=en&oi=scholarr

Chapitres de livres

2021
Bellal Belkacemi, Salah Saad. (2021), Inner and Outer Race Bearing Defects of Induction Motor Running at Low Speeds Signal Analysis with DWT. In book: Proceedings of the 12th International Conference on Soft Computing and Pattern Recognition (SoCPaR 2020) : Springer, https://link.springer.com/chapter/10.1007%2F978-3-030-73689-7_92

Résumé: This paper is focused on bearing inner and outer races defects considered as an important cause of bearing elements damage. The methods and techniques used and applied for the detection of defects in induction motors bearing suffer from some drawbacks such as difficulties of identifying bearing faults from the frequency spectrum because of non stationary vibration signals. For better faults localization, wavelet transform is the best technique for time-frequency analysis. Thus the Discrete Wavelet Transform (DWT) decomposition improved by MATLAB/Simulink toolbox is proposed in this work for signal analysis of bearing faults detection. In order to confirm the proposed procedure, an experimental rig for measuring vibratory signals of a bearing set driven by a 0.38 KW three phase induction motor operating at low speed (500 rpm) for healthy and two bearing faults (inner race and outer race defects). From the obtained results it can be concluded that the DWT enhanced by MATLAB/Simulink toolbox has shown its effectiveness and is appropriate for bearing inner and outer races faults detection.

2020
Larbi Hamiche, Salah Saad , Leila Merabet and Fares Zaamouche. (2020), Harmonic Current Identification by Adaline Neural Network and Real-Imaginary Instantaneous Powers Algorithm. Publisher: Book Publisher International : Book Publisher International, https://www.researchgate.net/publication/344446329

Résumé: This work is focused on harmonic current extraction and reactive power compensation using shunt active power filter (SAPF). In order to fulfil this objective an algorithm based on (ADALINE) Neural Network and Real and Imaginary Instantaneous Powers (ANN-RIIP) is developed to extract and identify harmonic components. Moreover, this algorithm estimates total harmonic current and also harmonic components individually. The developed algorithm is validated by computer simulation in MATLAB/Simulink environment and implemented experimental in a dSPACE 1104 controller. The method is easy to implement in real time compared to other methods such as pq. The results obtained by simulation are in concordance with the experimental results confirming the effectiveness of the proposed ANN-RIIP algorithm. The results have also demonstrated that the speed and accuracy of the proposed algorithm can improve the performances of active power filters.

2019
K. Baali, S. Saad, Y. Menasriya, F. Zaamouche. (2019), Implementation and Experimentation of (VSI) Applied for a Photovoltaic System. Computational Methods and Experimental Testing In Mechanical Engineering : Springer, https://link.springer.com/chapter/10.1007/978-3-030-11827-3_15

Résumé: In this paper, the simulation and real time implementation of a space vector pulse-width modulation (SVPWM) control scheme to demonstrate the high performance of the photovoltaic inverter when dSPACE is used as controller. The design and the simulation of electrical operation of a photovoltaic (PV) system controlled by an intelligent method enabling to track the maximum power produced by the photovoltaic generator are described. The simulation was performed in the Simulink/MATLAB environment and the PV output voltage is represented by a DC power supply of the inverter. Furthermore, tests are performed on experimental platform to implement the developed algorithms of SVPWM inverter used to convert the produced dc voltage to a variable AC voltage. The experimental waveforms such as ac output voltages, current and total harmonic distortion are presented and analyzed.

Communications internationales

2022
Meriem Behim, Leila Merabet, Salah Saad. (2022), Detection and Classification of Induction Motor Faults Using DWPD and Artificial Neural Network: Case of Supply Voltage Unbalance and Broken Rotor Bars : EasyChair Preprint, file:///C:/Users/pcc/Downloads/EasyChair-Preprint-7756%20(3).pdf

Résumé: It is obvious that time-frequency condition monitoring approaches have known better accuracy when combining it with AI techniques; however, this type of combined techniques is shyly applied, so it needs more encouragement. This article aims to detect and classify induction motor's defects, supply voltage unbalance and broken rotor bars, under several loads, with Artificial Neural Network (ANN), using as indicators: kurtosis and energy values. These values are calculated from Discrete Wavelet Packet Decomposition (DWPD) sub-bands of the stator current signals. The signals are obtained from the simulation of the squirrel cage induction motor (IM). The approach adopted here, is to treat the machine in terms of circuit. The occurred results are discussed

2021
Bellal Belkacemi, Salah Saad. (2021), Study and analysis vibration of external factors effects and their impact On Bearing using DWT decomposition. DZPOWER 21 International Conference Power and Energy Engineering (DZPOWER’21)https://dzenergy.org/dzpower/
Bellal Belkacemi, Salah Saad. (2021), Bearing various defects Analysis with DWT decomposition. DZPOWER 21 International Conference Power and Energy Engineering (DZPOWER’21)https://dzenergy.org/dzpower/
Behim Meriem, Merabet Leila, Saad Salah. (2021), Comparative study of time-frequency resolution: Application on broken rotor bars of an induction motor . International Conference on Innovative Applied Energy (Smart Exhibition) (DZENERGY 2021)
Naima Grabsia, Elias Hadjadj Aoul, Salah Saad. (2021), An Improved Fast Kurtogram Based on an Optimal Wavelet Coefficient for Wind Turbine Gear Fault Detection. ournal of Electrical Engineering & Technology : Springer Singapore, https://link.springer.com/article/10.1007/s42835-021-00937-9

Résumé: Serious failures of wind turbine drive-trains occur in gear which plays an essential role. Owing to the complicated vibration signal of faulty gear and the characteristic fault frequency buried in the background noise. Thus, detecting a defect of this component with classical methods is a great challenge. In order to overcome this issue, a combined technique of time–frequency analysis based on Morlet wavelet coefficient (MWC) and fast kurtogram (MWC-FK) is proposed for gear fault detection. The Morlet wavelet (MW) is able to detect components impulses and the fast Kurtogram (FK) is appropriate for environmental noise elimination and extracts the impulses in the filtered signal. First, the wavelet coefficient is obtained using the continuous Morlet wavelet transform decomposition for further analysis. Then, the wavelet coefficient signal that has the highest value of the kurtosis index is chosen. Finally, the selected signal is filtered by an optimal band-pass filter based on fast kurtogram. In order to confirm the usefulness and robustness of the proposed method, a real vibration signal of wind-turbine pinion with fault is used in this work. The results have showed the efficiency of the proposed method in gear fault detection and the extraction of fault characteristic frequencies by the squared envelope spectrum (SES) of the filtered Morlet wavelet coefficient signal.

Bellal Belkacemi, Salah Saad. (2021), Bearing various defects classification using deep network learning method. 3rd international conference on sustainable and innovative solutions for curent challenges in engineering and technology (ICSISCET 2021)https://www.icsiscet21.scrs.in/

Résumé: Diagnostics and classification of faults are critical today, especially in rotating machines, to prevent material and human losses. In order to classify bearing faults, this paper utilizes artificial intelligence methods, namely deep network learning. This field has used a variety of methods to detect and predict bearing faults, but none of them are foolproof or perfect. There are many drawbacks to most of these methods, such as the difficulty of extracting vibration signals. As a result of using deep network learning in the present study, the accuracy of the results have been improved compared to previous methods. The results have showed that the proposed technique is superior to the previously studied method and can be used to classify induction motor bearing faults effectively.

2020
Bellal Belkacemi, Salah Saad. (2020), Inner and outer race bearing defects of induction motor running at low speeds signal analysis with DWT . 16th International Conference on Information Assurance and Security (IAS 2020) held on the world wide web during December 15 - 18 , 2020 : Springer, http://www.mirlabs.org/ias20/

Résumé: The present work deals with bearing inner and outer races defects analysis using Discrete wavelet transform (DWT) decomposition finalized by MATLAB/ toolbox analysis. All previously studied methods and techniques used and applied for the detection of defects in induction motors bearing suffer from some drawbacks such as the difficulties of identifying bearing faults from the frequency spectrum because of non stationary vibration signals. In order to overcome this issue, the Discrete Wavelet Transform (DWT) decomposition is proposed for signal analysis as an efficient tool for various induction motor faults detection. In order to validate the proposed procedure, a setup is designed in LSELM laboratory for measuring vibratory signals of a bearing set driven by a 0.38 KW three phase induction motor operating at low speed (500tr/mn) for healthy and two bearing faults (inner race and outer race defects). The obtained results are discussed and analayzed

2019
(2019), Diagnosis of induction motor under abnormal voltages circumstances. 5 th international conference on advances in mechanical engineering (ICAME), Istanbulhttp://icame2019conference.com/

Résumé: The aim of this paper is to diagnose the unbalanced voltages in three phase induction motors. This voltage quality anomaly could cause serious problems, such as highly unbalanced currents on the stator and mécanical oscillations. In this work the detection of this fault is investigated by using the Extended Park Vector Approach (EPVA). The second harmonic component obtained by this technique, is often considered as a direct indicator of a stator winding fault in other researches. Hence this similarity leads to uncertainty in the detection of faults. Therefore it is required to specify the fault in a certain way by a complementary technique. In order to overcome these issues, motor current signature analysis (MCSA) and torque harmononic analysis (THA) are considered as perfect tools because of their suitability for the analysis.

(2019), Stator currents analysis in order to detect voltage inbalances in induction motors. 5 th International Conference on Advances in Mechanical Engineering Decembre 17-19, 2019http://icame2019conference.com/

Résumé: Three phase induction motor are exposed to different internal and external faults during operation. Stator unbalanced voltage is one of the most prevailing external faults that results in degradation of the performances of these motors. In order to diagnose this unhealthy condition, series of simulation tests through the stator current analysis techniques have been performed. First the Park vector technique and its extended approach (EPVA) are used. As a result, an elliptic pattern and a second harmonic component are clearly appeared, respectively by these methods under magnitude voltage unbalanceds. Second, the results of the motor current signature analysis (MCSA) and spectrograms method, suggest that the third harmonic component provide a powerful indicator for unbalanced voltages detection.

2018
(2018), Identification of harmonic currents in electrical networks by Adaline-Neuron. 3rd International Conferences on Electromechanical Engineering
(2018), New control method of PV pumping systems using fuzzy logic MPPT and DTC. International Conferences on Nanomaterials and Renewable Energies
(2018), A Discrete pulse width modulation techniques evaluation by analysis of voltage and current waveforms. 5th International Conferences on ACECS-2018 December 19-22 (2018), Hammamet Tunisia www.wikicfp.com/cfp/servlet/event.showcfp?eventid=38765
2017
(2017), Modelling and control of wind turbine doubly fed induction generator with MATLAB simulink. International conference Turkey : DOI: 10.18844/gjcs.v7i2.2714, https://www.researchgate.net/publication/321536116_link

Résumé: This paper describes the modelling and control system of a wind turbine, using a doubly fed induction generator. This configuration makes the wind turbine suitable for variable speed wind energy application. The power captured by the wind turbine is converted into electrical power by the induction generator, and it is transmitted to the grid by the stator and the rotor windings. The control system generates voltage command signals for rotor converter and grid converter, respectively, in order to control the power of the wind turbine. Reactive power exchanged with the network through the converters is set to 0 VAr. The control strategy has been developed using MATLAB/Simulink. The simulation results are presented and discussed in the conclusions. Keywords: Wind energy, doubly fed induction generator, grid power, modelling, control

2015
(2015), Transformer fault diagnosis using Dissolved Gas Analysis technology and Bayesian networks. Systems and Control (ICSC), 2015 4th International Conference on systems and control : IEEE, https://ieeexplore.ieee.org/document/7152759/

Résumé: Bayesian model is developed for transformer faults diagnosis using dissolved gas in oil analysis. DGA (Dissolved Gas Analysis) is the traditional and conventional transformer fault diagnosis method, which mainly depends on the experience of operators and of the percentages of dissolved gases. In addition, the only measurement of the gases percentage is not sufficient to evaluate the equipment health. There are several cases where the proportions of dissolved gases remain trapped in the transformer. Regarding this uncertainty and in order to make decisions in a certain environment, the model developed in this study represents a powerful tool for decision making. In addition, one traditional method of DGA does not enable the diagnosis of all faults, for example the Rogers Ratio Method diagnose five faults only, but using the proposed Bayesian network (BN) it is possible to diagnose all faults from the same model. To illustrate the advantages of Bayesian methods in transformer fault diagnosis, a study of power station main transformer is conducted and the results are analyzed and discussed

(2015), Fuzzy, logic controller of fîve levels active power filter. International conference on TMREES15 : Elsevier, https://core.ac.uk/download/pdf/82008368.pdf

Résumé: This paper presents five-level inverter as a shunt active power filter (SAPF) to compensate reactive power and suppresses harmonics drawn from a diode rectifier supplying RL load under distorted voltage conditions. The harmonic current extraction is based on the use of self tuning filter (STF) and fuzzy logic controller employed to control harmonic current and inverter DC voltage. The aim of the present work is to obtain a perfect compensation by extracting accurate harmonic currents to improve the performances of the five-levels active power filters. The proposed scheme is validated by computer simulation using MATLAB Fuzzy Logic Toolbox in order to show the effectiveness and ability of this method. The results have demonstrated that the proposed shunt active power filter with STF and Fuzzy Logic Controller (FLC) have produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

(2015), Minimisation of resonance phenomena effect of piezoresistive accelerometer. (ICSC), 2015 4th International Conference on Systems and Control : 1EEE, https://ieeexplore.ieee.org/abstract/document/7152757

Résumé: In this paper, a suitable mathematical model of piezoresistive accelerometer is developed and validated by simulation tests. A new relationship is found between the movement relative frequency and piezoresistive accelerometer natural frequency. This relationship is represented by a new formula that selects for each frequency range a suitable piezoresistive accelerometer and thus, resonance effect is minimized.

2013
(2013), Improvement of piezoresistive accelerometer performance. 3rd International Conference on Systems and Control (ICSC) : IEEE, https://ieeexplore.ieee.org/document/6750943/

Résumé: In the present paper, piezoresistive accelerometer performance is improved by the development of a suitable mathematical model. The simulation of the developed model allows selecting the best value of damping rate to minimize the measurement error to 1%. This model is validated by a series of tests carried out by computer simulation. The obtained results have showed that a suitable dumping rate can minimize measurement error of relative movement to 1 %. Using the present model, the dumping rate and precision error of the accelerometer can be improved.

(2013), Development of measurement precision of vibration sensor. In proceeding of: International Conference on Systems and Control, At Algiers, Algeria
(2013), Comparative study of PWM inverter techniques by simulation and experimental tests . First International Conference on Electrical Energy and Systems ICEES'2013 : Université Badji Mokhtar-Annaba,
2012
(2012), A comparative study of harmonic current identification for active power filter. Renewable Energies and Vehicular Technology (REVET), 2012 First International Conference : IEEE, https://ieeexplore.ieee.org/document/6195298/

Résumé: Active power filter requires accurate harmonic current identification to compensate harmonics in power system distribution. The purpose of this paper is to present a comparative study of two techniques for harmonics currents identification based on P-Q theory and Adaline(ADAptiveLINear Element) neural networks. The harmonic current can be identified from powers or currents. The first method is based on the instantaneous powers taking advantage from relationship between load currents and power transferred from the supply source to the loads. The second method concerns the artificial neural networks based on the LMS (least mean square) algorithm. This approach adjusts the weights by iteration and provides more flexibility to perform the compensation. The developed architecture is validated by computer simulation proving its effectiveness, capability and robustness.

(2012), Harmonic Current Identification with Artificial Neural Network for Active Power Filter. 7th international Electrical Engineering Conference CEE’12 University of Batna, Aleriawww.cee2012.univ-batna.dz
(2012), Auto-adaptivité du Filtre Actif à Quatre Bras au Variation de la Charge. 7th international Electrical Engineering Conference CEE’12 University of Batna Algeria www.cee2012.univ-batna.dz
2011
(2011), Approche neuronale des composantes directes et la poursuite de la fréquence dans un réseau. ICSIP’11, 2011, Guelma, Alegriawww.univ-guelma.dz
2010
(2010), Three Level Series Active Power Filter. ICEN’10 September 28-29, 2010, Sidi Bel Abbès University, Algeria www.univ-sba.dz
(2010), Three Level Series Active Power Filter compensating harmonics and reactive power. ICEN’10 September 28-29, 2010, Sidi Bel Abbès Universitywww.univ-sba.dz
(2010), Fuzzy logic controller of Three Level Series Active power Filter. EFEEA'10, Ghardaia, 2-4 November, 2010, Algeria www.univ-ouargla.dz
2008
(2008), Comparison of fuzzy logic and proportional controller of shunt active filter compensating current. 2nd ICEEDT08. Hammamet, Tunisia
(2008), Comparison of FL and P controller of shunt active filter compensating current harmonics and P.Fhttps://scholar.google.com/citations?user=_x9MWRIAAAAJ&hl=en#d=gs_md_cita-d&p

Résumé: The paper describes and compares the application of fuzzy logic controller and proportional controller to a three phase shunt active power filter used to compensate harmonic current and reactive power of nonlinear loads simultaneously.

2007
(2007), Fuzzy Logic Controller for Three-phase Shunt Active Filter Compensating Harmonics and Reactive Power. International Conference on Computer Integrated Manufacturing CIP’, Setif, Algeria

Résumé: This paper presents a fuzzy logic as a control technique applied to a voltage source inverter operating as an active filter. This active filter compensates harmonic current and reactive power of nonlinear loads simultaneously. The proposed scheme uses a pulse width modulation (PWM) technique to generate the switching signals to the active filter, pq theory for harmonic current identification and fuzzy logic for active filter current and DC capacitor voltage control. The operation and design of power and control circuit of active filter are analyzed and discussed. The obtained results using MATLAB power system blocks showed that source current is sinusoidal and in phase with source voltage. The proposed solution has achieved a low total harmonic distortion demonstrating the effectiveness of the presented method.

Communications nationales

2018
(2018), New control method of PV pumping systems using fuzzy logic MPPT and DTC. International Conferences on Nanomaterials and Renewable Energies
2010
(2010), Three Level Shunt Active Filter Compensating Harmonics and Reactive Power. GEAER’10 Chlef le 28 novembre 2010
2007
(2007), Reduction des harmoniques à la sortie de l'onduleur de tension triphasé commandé par MLI vectorielle. Séminaire National du 12-11 Mars 2007 Skikda : Hindawi,
2005
(2005), Méthodologie causal pour la commande des machines asynchrones . ICEL-2005, Novembre 13-14 2005, Oran Algérie
2003
(2003), Filtrage actif parallèle des harmoniques de courant. SNSEM 2003, 12-13 Octobre 2003 Annaba
(2003), Détermination de la fréquence de découpage adéquate pour réduire les courants harmoniques. SNSEM 2003, 12-13 Octobre 2003 Annaba