Ziad OBEID - Academia.edu (original) (raw)
Papers by Ziad OBEID
Cet article traite de la detection de defauts de roulements dans les entrainements electromecaniq... more Cet article traite de la detection de defauts de roulements dans les entrainements electromecaniques par analyse des courants d’alimentation des moteurs electriques. Les defaillances auxquelles nous nous interessons concernent principalement les usures des surfaces de contact ainsi que la perte des proprietes lubrifiantes de la graisse des roulements. Nous mettons a profit certaines signatures frequentielles des courants statoriques pour detecter les oscillations du couple de charge induites par les degradations des roulements.
MATEC Web of Conferences, 2018
Nowadays, a strong link exists between human comfort and electrical power. Abundant doings are no... more Nowadays, a strong link exists between human comfort and electrical power. Abundant doings are not possible without the support of the electrical energy. Driven by the human obligation to save the environment, the installation of PV solar system increased dramatically in the past numerous years. The installation can be grid connected or standalone system. These micro-grid situations are installed world-wide and currently are contributing to the local electrical network. To maximize the use of the generated solar system, numerous system installed energy storage in the form of batteries. These energy storages harvest the sun power during daylight to support the household electrical demand after sunset. This paper linked the house roof design to the PV solar system for maximum generation condition. Furthermore the paper contains important information on the optimum location for the solar panel to ensure continuous and reliable system is achieved. An actual real case study is presented.
2016 IEEE Electrical Power and Energy Conference (EPEC), 2016
2016 3rd International Conference on Renewable Energies for Developing Countries (REDEC), 2016
Electrical power energy forms an indispensable part of human comfort. Numerous activities would h... more Electrical power energy forms an indispensable part of human comfort. Numerous activities would have been impossible without the aid of electricity. The introduction of the PV solar system introduces additional challenges to engineers on how to increase the efficiency of the system. Micro grid PV generations spread worldwide by installing small size PV system on the roof top of residential properties. The maximum output of the PV system is at midday where working families are away from homes. Without the storage system, this energy can only be injected into the electrical grid. This paper introduces the concept of electrical management system for smart home. The proposed smart system allows percentage of the PV generated energy to be used during working hours. Also, the proposed system gives the individual a total control to maximize the use of generated energies, reduce the electricity bills and the impact on the environment. Case study is included
2016 3rd International Conference on Renewable Energies for Developing Countries (REDEC), 2016
In this paper, an optimization algorithm has been applied on a group of interconnected microgrids... more In this paper, an optimization algorithm has been applied on a group of interconnected microgrids with the main grid. The objective is to maximize the benefits for all the elements of the grid. Results have shown the performance of the proposed algorithm.
2015 19th International Conference on System Theory, Control and Computing (ICSTCC), 2015
In this paper an optimization algorithm is applied on a microgrid with renewable energy and distr... more In this paper an optimization algorithm is applied on a microgrid with renewable energy and distributed generation. The intermittent electricity in Lebanon leads to widely use diesel generator groups and to install renewable energy in private places in order to cover the consumption during the power cut. The proposed case study consists of three energy hubs integrating renewable energy, diesel engines, and batteries. These three energy hubs cooperate and exchange extra power if needed by applying the proposed algorithm while minimizing the use of diesel engine groups.
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
In this paper, an original method to compute an indicator for efficient detection of bearing defa... more In this paper, an original method to compute an indicator for efficient detection of bearing defaults in high speed synchronous machines is presented. This indicator is based on the statistical analysis of the stator current spectrum. The principle of the method is to compare the current spectrum to a healthy reference spectrum. The reference spectrum is used to center and reduce the current spectrum and provides an indication on its difference from the reference spectrum. A statistical based indicator is then constructed as the sum of the contributions of the centered reduced spectrum for different interesting frequency bands. This indicator has been tested on 2 different test campaigns, for 4 different speeds and compared a vibratory indicator. Results show that the proposed indicator evolves the same way than the vibratory indicator and provides with an efficient detection of bearing fault with only very few false alarms.
Mechanical Systems and Signal Processing, 2014
In this paper, an original method for bearing fault detection in high speed synchronous machines ... more In this paper, an original method for bearing fault detection in high speed synchronous machines is presented. This method is based on the statistical process of Welch's periodogram of the stator currents in order to obtain stable and normalized fault indicators. The principle of the method is to statistically compare the current spectrum to a healthy reference so as to quantify the changes over the time. A statistic-based indicator is then constructed by monitoring specific harmonic family. The proposed method was tested on two experimental test campaigns for four different speeds and compared to a vibration indicator. The method was evaluated using a rigorous performance evaluation metric. A threshold evaluation was performed and shows that the proposed method is very tolerant to the machine speed. Thus, the use of a unique fault threshold whatever the speed can be considered. Results showed excellent agreement as compared with the vibration indicator, with an overall correlation of r ¼0.74 and only 4% of false alarms. Performance demonstrated by this novel method was superior to those of a classical energy-based indicator in terms of correlation with the vibration indicator and detection stability. Moreover, results also showed a better robustness of the proposed method since good performance can be obtained with the same detection threshold whatever the speed or the measure campaign whereas it needs to be redefined for each case with the classical indicator. This work shows the advantages of a statistic-based approach in order to increase the robustness of bearing fault detection in permanentmagnet synchronous machines.
Http Www Theses Fr, Jul 5, 2012
Ce travail de these traite de la detection des defauts mecaniques des roulements a billes par ana... more Ce travail de these traite de la detection des defauts mecaniques des roulements a billes par analyse de grandeurs mecaniques et electriques dans des machines synchrones a aimants permanents haute vitesse. Le domaine applicatif de ce travail concerne l'aeronautique. Generalement, pour surveiller l'etat des roulements a billes dans un actionneur electrique, des mesures vibratoires sont realisees. Elles permettent, en exploitant le spectre du signal vibratoire, de mettre facilement en evidence la deterioration du roulement. Cette methode de surveillance est cependant relativement couteuse en termes d'instrumentation et le placement d'un capteur vibratoire dans des equipements a fort degre d'integration est parfois difficile. Nous proposons dans ce memoire d'utiliser d'autres grandeurs physiques prelevees sur le systeme pour realiser la surveillance de ces defauts. Il peut s'agir de grandeurs mecaniques (vitesse, position par exemple) et de grandeurs electriques (courant statorique, courant onduleur par exemple). L'utilisation de donnees deja disponibles dans l'equipement pour les besoins de la commande permet ainsi de supprimer le systeme d'acquisition vibratoire. A partir d'enregistrements temporels de donnees realisees au cours de campagnes d'essais, nous proposons des methodologies de traitement du signal permettant d'extraire automatiquement des informations sensibles au defaut a surveiller. L'idee finale est de construire des indicateurs de l'etat de sante des roulements permettant de prendre « juste a temps » des decisions fiables relatives a la maintenance ou a la securisation de l'equipement. Pour construire ces indicateurs, les signatures specifiques aux defauts de roulements sont etudiees de maniere theorique et experimentale, pour l'ensemble des grandeurs prelevees. Leurs proprietes sont mises en evidence, permettant ainsi de definir les bandes frequentielles les plus contributives au diagnostic. L'extraction de ces signatures est realisee dans le domaine frequentiel selon plusieurs methodes. Deux types d'indicateurs automatiques differents sont proposes. Le premier est construit directement a partir du spectre d'amplitude des grandeurs par extraction de l'amplitude des harmoniques dans des bandes frequentielles particulieres. Le second integre une dimension statistique dans l'analyse en exploitant le caractere aleatoire de certains harmoniques pour detecter la presence du defaut. Des criteres de comparaison sont definis et utilises pour etudier les performances des indicateurs proposes pour deux campagnes d'essais avec des roulements artificiellement degrades, pour differentes vitesses de fonctionnement et pour differents parametres de reglage des indicateurs.
Cet article traite de la detection de defauts de roulements dans les entrainements electromecaniq... more Cet article traite de la detection de defauts de roulements dans les entrainements electromecaniques par analyse des courants d’alimentation des moteurs electriques. Les defaillances auxquelles nous nous interessons concernent principalement les usures des surfaces de contact ainsi que la perte des proprietes lubrifiantes de la graisse des roulements. Nous mettons a profit certaines signatures frequentielles des courants statoriques pour detecter les oscillations du couple de charge induites par les degradations des roulements.
MATEC Web of Conferences, 2018
Nowadays, a strong link exists between human comfort and electrical power. Abundant doings are no... more Nowadays, a strong link exists between human comfort and electrical power. Abundant doings are not possible without the support of the electrical energy. Driven by the human obligation to save the environment, the installation of PV solar system increased dramatically in the past numerous years. The installation can be grid connected or standalone system. These micro-grid situations are installed world-wide and currently are contributing to the local electrical network. To maximize the use of the generated solar system, numerous system installed energy storage in the form of batteries. These energy storages harvest the sun power during daylight to support the household electrical demand after sunset. This paper linked the house roof design to the PV solar system for maximum generation condition. Furthermore the paper contains important information on the optimum location for the solar panel to ensure continuous and reliable system is achieved. An actual real case study is presented.
2016 IEEE Electrical Power and Energy Conference (EPEC), 2016
2016 3rd International Conference on Renewable Energies for Developing Countries (REDEC), 2016
Electrical power energy forms an indispensable part of human comfort. Numerous activities would h... more Electrical power energy forms an indispensable part of human comfort. Numerous activities would have been impossible without the aid of electricity. The introduction of the PV solar system introduces additional challenges to engineers on how to increase the efficiency of the system. Micro grid PV generations spread worldwide by installing small size PV system on the roof top of residential properties. The maximum output of the PV system is at midday where working families are away from homes. Without the storage system, this energy can only be injected into the electrical grid. This paper introduces the concept of electrical management system for smart home. The proposed smart system allows percentage of the PV generated energy to be used during working hours. Also, the proposed system gives the individual a total control to maximize the use of generated energies, reduce the electricity bills and the impact on the environment. Case study is included
2016 3rd International Conference on Renewable Energies for Developing Countries (REDEC), 2016
In this paper, an optimization algorithm has been applied on a group of interconnected microgrids... more In this paper, an optimization algorithm has been applied on a group of interconnected microgrids with the main grid. The objective is to maximize the benefits for all the elements of the grid. Results have shown the performance of the proposed algorithm.
2015 19th International Conference on System Theory, Control and Computing (ICSTCC), 2015
In this paper an optimization algorithm is applied on a microgrid with renewable energy and distr... more In this paper an optimization algorithm is applied on a microgrid with renewable energy and distributed generation. The intermittent electricity in Lebanon leads to widely use diesel generator groups and to install renewable energy in private places in order to cover the consumption during the power cut. The proposed case study consists of three energy hubs integrating renewable energy, diesel engines, and batteries. These three energy hubs cooperate and exchange extra power if needed by applying the proposed algorithm while minimizing the use of diesel engine groups.
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
In this paper, an original method to compute an indicator for efficient detection of bearing defa... more In this paper, an original method to compute an indicator for efficient detection of bearing defaults in high speed synchronous machines is presented. This indicator is based on the statistical analysis of the stator current spectrum. The principle of the method is to compare the current spectrum to a healthy reference spectrum. The reference spectrum is used to center and reduce the current spectrum and provides an indication on its difference from the reference spectrum. A statistical based indicator is then constructed as the sum of the contributions of the centered reduced spectrum for different interesting frequency bands. This indicator has been tested on 2 different test campaigns, for 4 different speeds and compared a vibratory indicator. Results show that the proposed indicator evolves the same way than the vibratory indicator and provides with an efficient detection of bearing fault with only very few false alarms.
Mechanical Systems and Signal Processing, 2014
In this paper, an original method for bearing fault detection in high speed synchronous machines ... more In this paper, an original method for bearing fault detection in high speed synchronous machines is presented. This method is based on the statistical process of Welch's periodogram of the stator currents in order to obtain stable and normalized fault indicators. The principle of the method is to statistically compare the current spectrum to a healthy reference so as to quantify the changes over the time. A statistic-based indicator is then constructed by monitoring specific harmonic family. The proposed method was tested on two experimental test campaigns for four different speeds and compared to a vibration indicator. The method was evaluated using a rigorous performance evaluation metric. A threshold evaluation was performed and shows that the proposed method is very tolerant to the machine speed. Thus, the use of a unique fault threshold whatever the speed can be considered. Results showed excellent agreement as compared with the vibration indicator, with an overall correlation of r ¼0.74 and only 4% of false alarms. Performance demonstrated by this novel method was superior to those of a classical energy-based indicator in terms of correlation with the vibration indicator and detection stability. Moreover, results also showed a better robustness of the proposed method since good performance can be obtained with the same detection threshold whatever the speed or the measure campaign whereas it needs to be redefined for each case with the classical indicator. This work shows the advantages of a statistic-based approach in order to increase the robustness of bearing fault detection in permanentmagnet synchronous machines.
Http Www Theses Fr, Jul 5, 2012
Ce travail de these traite de la detection des defauts mecaniques des roulements a billes par ana... more Ce travail de these traite de la detection des defauts mecaniques des roulements a billes par analyse de grandeurs mecaniques et electriques dans des machines synchrones a aimants permanents haute vitesse. Le domaine applicatif de ce travail concerne l'aeronautique. Generalement, pour surveiller l'etat des roulements a billes dans un actionneur electrique, des mesures vibratoires sont realisees. Elles permettent, en exploitant le spectre du signal vibratoire, de mettre facilement en evidence la deterioration du roulement. Cette methode de surveillance est cependant relativement couteuse en termes d'instrumentation et le placement d'un capteur vibratoire dans des equipements a fort degre d'integration est parfois difficile. Nous proposons dans ce memoire d'utiliser d'autres grandeurs physiques prelevees sur le systeme pour realiser la surveillance de ces defauts. Il peut s'agir de grandeurs mecaniques (vitesse, position par exemple) et de grandeurs electriques (courant statorique, courant onduleur par exemple). L'utilisation de donnees deja disponibles dans l'equipement pour les besoins de la commande permet ainsi de supprimer le systeme d'acquisition vibratoire. A partir d'enregistrements temporels de donnees realisees au cours de campagnes d'essais, nous proposons des methodologies de traitement du signal permettant d'extraire automatiquement des informations sensibles au defaut a surveiller. L'idee finale est de construire des indicateurs de l'etat de sante des roulements permettant de prendre « juste a temps » des decisions fiables relatives a la maintenance ou a la securisation de l'equipement. Pour construire ces indicateurs, les signatures specifiques aux defauts de roulements sont etudiees de maniere theorique et experimentale, pour l'ensemble des grandeurs prelevees. Leurs proprietes sont mises en evidence, permettant ainsi de definir les bandes frequentielles les plus contributives au diagnostic. L'extraction de ces signatures est realisee dans le domaine frequentiel selon plusieurs methodes. Deux types d'indicateurs automatiques differents sont proposes. Le premier est construit directement a partir du spectre d'amplitude des grandeurs par extraction de l'amplitude des harmoniques dans des bandes frequentielles particulieres. Le second integre une dimension statistique dans l'analyse en exploitant le caractere aleatoire de certains harmoniques pour detecter la presence du defaut. Des criteres de comparaison sont definis et utilises pour etudier les performances des indicateurs proposes pour deux campagnes d'essais avec des roulements artificiellement degrades, pour differentes vitesses de fonctionnement et pour differents parametres de reglage des indicateurs.