http://depot.umc.edu.dz/handle/123456789/6016 2026-10-24T22:55:30Z 2026-10-24T22:55:30Z Touil, Abderrahim Babaa, Fatima http://depot.umc.edu.dz/handle/123456789/14864 2026-10-20T10:50:58Z 2024-12-23T00:00:00Z

Diagnostic des defauts de roulements dans les machines electriques. Touil, Abderrahim; Babaa, Fatima The widespread use of asynchronous motors is primarily attributed to their superiority over other motor types. They are notably cost-effective when it comes to maintenance. As such, it is essential to implement robust protective measures against major faults and to establish an effective functional monitoring system incorporating efficient preventive maintenance strategies. Predictive maintenance, in particular, can significantly enhance the cost-effectiveness and reliability of installations. The machine’s behavior evolves under varying fault conditions, making accurate fault identification critical and requiring a detailed and thorough analysis of the motor. In this context, the objective of our work is to diagnose faults that affect the motor throughout its operational lifespan. This is achieved using a model based on the detailed calculation of all the machine’s inductances. Among the most common faults is bearing failure, which is a key focus for devising an optimal maintenance strategy. Therefore, it is crucial to identify specific fault signatures that enable the prediction of fault progression. By analyzing various signals, we aim to extract reliable indicators and signatures that can be used not only for accurate fault prediction but also in industrial applications. To validate our analytical developments, experimental validation is indispensable. This step serves to confirm the accuracy of the simulated results for the various faults studied. To achieve this, test benches were employed to corroborate the findings derived from analytical calculations. Ultimately, the results obtained are highly indicative, particularly for faults such as power supply imbalances and bearing failures, and show strong alignment with findings reported in the literature.

2024-12-23T00:00:00Z Bouabid, Nourelhouda Khezzar, Abdelmalek http://depot.umc.edu.dz/handle/123456789/14832 2026-02-11T10:43:23Z 2023-11-29T00:00:00Z

Contrôle et continuité de fonctionnement du moteur asynchrone à l’aide de la carte DSPACE 1104. Bouabid, Nourelhouda; Khezzar, Abdelmalek This work provides a new diagnosis method for broken bar and mixed air gap eccentricity faults in the closed loop control of a squirrel cage induction motor. The closed loop system is widely used in industrial applications due to the efficiency of the variables of the regulator outputs for diagnosis because it directly shows the action of the control. The regulator will continue to force the controlled variables to the reference value, resulting in a decrease in the magnitude of the diagnostic indicators and a loss of information critical for detecting faults that cause a motor disaster. This work Based on the direct stator current fault signature as well as the speed fault signature to return the real magnitude of the fault diagnosis indices without affecting the indirect field control. Furthermore, the real magnitude is used to compensate for the fault magnitude and to obtain a machine operating in a healthy state. Using the discrete Fourier transformation. The transfer function is utilized to find the analytical expression of the measured electrical and mechanical parameters at both conditions. The fault signature and error of the torque are used to compensate for the fault signature speed, torque, and quadrature stator current. The simulation and experiment results are included to verify the effectiveness of the theoretical analysis.

2023-11-29T00:00:00Z Bouderres, Nacer Kerdoun, Djallel Djellad, Abdelhak http://depot.umc.edu.dz/handle/123456789/14821 2026-01-20T14:11:46Z 2023-10-12T00:00:00Z

Modélisation et simulation d’une chaine de conversion photovoltaïque. Bouderres, Nacer; Kerdoun, Djallel; Djellad, Abdelhak The integration of photovoltaic (PV) systems into the electrical grid faces numerous technical challenges, including the reliable and efficient export of energy to the grid while ensuring energy quality requirements. In this context, the objective of this work is to significantly contribute to the improvement and optimization of a PV system connected to a distribution grid. To achieve this, MPPT (Maximum Power Point Tracking) algorithms are applied to optimize the energy production at the source. Subsequently, a VOC (Voltage Oriented Control) is implemented on the DC/AC converter using PSO optimization technique for both classical PI and FOPI regulators, ensuring a better connection to the grid. Mathematical models of the system components have been developed and validated through simulation using MATLAB/Simulink. According to the obtained simulation results, it has been observed that the VOC control strategy using the PSO-FOPI regulator meets the performance criteria in terms of rapidity, stability and precision with an optimized total harmonic distortion (THD) rate. These results demonstrate the efficiency and reliability of the proposed system.

2023-10-12T00:00:00Z Oualah, Oussama Kerdoun, Djallel http://depot.umc.edu.dz/handle/123456789/14816 2026-01-20T09:01:38Z 2023-09-27T00:00:00Z

Contribution à la commande des machines électriques Oualah, Oussama; Kerdoun, Djallel The objective of this thesis is to optimize the design of a wind energy conversion system by establishing an optimal balance between cost, energy efficiency, system performance, and the quality of energy injected into the electrical grid. To achieve this objective, we conducted modeling, control, and simulation of a wind generator consisting of a wind turbine, a brushless doubly fed reluctance machine BDFRM, back-to-back converters, and a control block.The control block is divided into two parts: generator-side converter control and gridside converter control. Modeling of various control-related elements, such as the DC bus and the GSC-grid link filter, was performed. The primary stator of the machine, operating as a generator, is directly connected to the electrical grid, while the secondary stator is connected via back-to-back converters, enabling control of the entire wind system. Techniques such as stator flux orientation, first and second-order sliding mode control, and Maximum Power Point Tracking (MPPT) control were applied to the control block to independently control the active and reactive powers sent to the electrical grid by the generator and extract maximum power.Simulation results of the overall wind system demonstrate the effectiveness of the MPPT control. They confirm that independent control of the active and reactive powers sent to the electrical grid by the wind generator has been successfully achieved using stator flux orientation. The nonlinear control methods examined in this study have demonstrated high performance in managing the wind energy conversion system. Simulation results have confirmed the efficiency and robustness of each method in terms of tracking, unity power factor operation, decoupling, response time, and current quality.

2023-09-27T00:00:00Z