Dissertations / Theses on the topic 'Machines – Défauts'
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Plazenet, Thibaud. "Contribution à l'analyse de défauts de roulement induits par les défauts électriques de machines tournantes." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0187.
Full textPremature bearing aging is one of the main reasons of forced outages of electrical machines, especially under converter operation. This work contributes to the analysis and the detection of the generalized roughness bearing fault in small machines (up to 20 kW) under converter operation. In this configuration, this fault is caused by capacitive discharges creating an electroerosion of the raceways. To detect this fault, we proposed a realistic aging process that reproduces the emerging state of the generalized roughness bearing fault. This experimental process consists of an inverter located between the raceways and designed to increase the discharge activity while limiting the energy of a single discharge to a realistic threshold. Operating conditions, which accelerate the bearing aging by increasing the discharge activity, are experimentally determined. In this thesis, we also tackle the problem of detecting the generalized roughness bearing fault. In accordance with the maintenance constraints and the effects produced by the fault on vibration signals, we selected appropriate signal processing tools. The creation of synthetic vibration signals, enriched with some properties of the fault, allowed a comparative study of the proposed detection methods, which are based on the Wiener filter, the spectral subtraction and the spectral kurtosis
Bahri, Elmehdi. "Minimisation active des contraintes générées par les défauts dans les machines électriques : application à la MSAPS." Thesis, Artois, 2017. http://www.theses.fr/2017ARTO0201/document.
Full textThe work carried out in this thesis consists in developing a methodology to reduce the torque ripples generated by a stator fault in a surface permanent magnet synchronous machine. Two faults have been treated: the unbalance of the stator winding, illustrated in the study by a lack of turns, and a stator inter-turns short-circuit. The harmonic torque components generated by the both faults have been identified and the inverse current component to be injected in the supply currents has been determined to reduce the main torque component, which is at twice the supply frequency. Two approaches have been used to determine this inverse current component: an approach based on the air gap flux density resulting from an analytical calculation taking into account the magnetic effect of the currents in each slot, and an approach based on the flux and current space phasor. This second approach makes it possible to implement the correction principle in matlab-simulink simulations. These simulations give convincing results whether the machine operates in a frequency-controlled open loop or in a vector control mode inserted in a speed control loop. Experimental tests have been realized to validate the theoretical study. The used test bench includes a Permanent Magnet Synchronous Machine (PMSM) coupled to a DC machine. The PMSM is powered by an inverter controlled by a dSPACE system able to tune the inverse current component and ensure the vector control. A properly positioned accelerometer is used to measure the tangential vibrations generated by torque fluctuations. For both faults, the reduction of the harmonic of tangential vibrations at twice the supply frequency was demonstrated by injection of an inverse current component. A good agreement between theory and experimentation in terms of the amplitude of the inverse component was obtained
Alachkar, Bassem. "Diagnostic vibro-acoustique des défauts de fabrication des machines électriques." Paris 11, 1995. http://www.theses.fr/1995PA112190.
Full textRouached, Bouali, and Bouali Rouached. "Contribution à la modélisation des défauts de bobinages des machines électriques et à leur détection par des mesures au rotor." Doctoral thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69310.
Full textCe travail de thèse traite de la détection des défauts de bobinages au stator dans les machines électriques contenant une structure d'amortissement. Les courts-circuits entre spires d'un même enroulement sont souvent la prémisse de l'apparition d'autres défauts de bobinages dont les conséquences sont plus sévères. La précocité de détection est donc essentielle pour préserver les machines et leur environnement humain ou matériel. Dans cet ouvrage, nous proposons une solution innovante de discrimination des courts-circuits basée sur la redondance de signaux mesurés au rotor. Pour définir celle-ci, une modélisation d'ordre élevé combinant l'approche des éléments finis et celle des circuits couplés a été employée. La première est utilisée pour déterminer les paramètres (couplages magnétiques) exploités par la seconde qui n'est autre que le modèle comportemental. Comme l'inconvénient de cette combinaison d'approches est le temps utile à l'identification des couplages magnétiques et sachant que diverses configurations de bobinage doivent être modélisées, une nouvelle méthodologie d'identification a été développée. Après une première identification (éléments finis) à temps réduit, celle-ci offre la possibilité d'estimer les paramètres d'une configuration de bobinage souhaitée sans réutilisation de la résolution par éléments finis. En plus de son exploitation pour mettre en œuvre le procédé de détection présenté, cette méthodologie d'identification est un générateur de paramètres utiles pour des détections basées sur « l'estimation paramétrique ». La modélisation des circuits couplés présente un excellent rapport précision/temps de calcul et une bonne efficacité dans la représentation des phénomènes spatiotemporels. L'intégration d'un défaut de bobinage nécessite de faire évoluer les équations de circuits du modèle. À des fins d'atteindre l'objectif de cette thèse, la structure du modèle a été modifiée pour introduire les courts-circuits entre spires au stator. En dehors de l'application présentée, l'association de la méthode d'identification avec le modèle comportemental permet la reproduction rapide de forme d'onde multiple, notamment exploitable dans les approches de détection orientée « signal ». Enfin, à partir de l'outil résultant des travaux précédents, le procédé de diagnostic a pu être déterminé. La sensibilité de détection est le critère principal pour la définition de la technique instrumentale et des traitements de signaux du procédé. L'influence des conditions de fonctionnement sur la sensibilité de détection est évaluée et est considérée pour le choix des solutions retenues. Ce procédé a été validé expérimentalement sur un alternateur synchrone à rotor bobiné de 5.4KVA.
This thesis deals with the detection of stator winding faults in electrical machines containing a damping structure. Short-circuits between turns of the same winding are often the premise for the appearance of other winding faults, the consequences of which are more severe. Early detection is therefore essential to preserve machines and their human or material environment. In this book, we propose an innovative solution to short-circuit discrimination based on the redundancy of signals measured at the rotor. To define this, high-order modelling combining the finite element approach and that of coupled circuits was used. The first is used to determine the parameters (magnetic couplings) exploited by the second which is none other than the behavioural model. As the downside of this combination of approach is the time taken to identify magnetic couplings and the knowledge that various coil configurations must be modelled, a new identification methodology was developed. After an initial identification (finite elements) at short notice, this offers the possibility of estimating the parameters of a desired winding configuration without reusing the finite element resolution. In addition to its use to implement the detection method presented, this identification methodology is a generator of useful parameters for detections based on "parametric estimation". The modelling of coupled circuits presents an excellent precision / calculation time ratio and a good efficiency in the representation of spatial-temporal phenomena. Integrating a winding fault requires changing the model's circuit equations. In order to achieve the objective of this thesis, the structure of the model has been modified to introduce the short circuits between turns at the stator. Apart from the application presented, the association of the identification method with the behavioural model allows the rapid production of multiple waveforms, particularly usable in "signal" oriented detection approaches. Finally, from the tool resulting from the previous work, the diagnostic process could be determined. The detection sensitivity is the main criterion for the definition of the instrumental technique and the signal processing of the process. The influence of the operating conditions on the detection sensitivity is evaluated and is considered for the choice of the solutions adopted. This process has been validated experimentally on a synchronous alternator with wound rotor of 5.4KVA.
This thesis deals with the detection of stator winding faults in electrical machines containing a damping structure. Short-circuits between turns of the same winding are often the premise for the appearance of other winding faults, the consequences of which are more severe. Early detection is therefore essential to preserve machines and their human or material environment. In this book, we propose an innovative solution to short-circuit discrimination based on the redundancy of signals measured at the rotor. To define this, high-order modelling combining the finite element approach and that of coupled circuits was used. The first is used to determine the parameters (magnetic couplings) exploited by the second which is none other than the behavioural model. As the downside of this combination of approach is the time taken to identify magnetic couplings and the knowledge that various coil configurations must be modelled, a new identification methodology was developed. After an initial identification (finite elements) at short notice, this offers the possibility of estimating the parameters of a desired winding configuration without reusing the finite element resolution. In addition to its use to implement the detection method presented, this identification methodology is a generator of useful parameters for detections based on "parametric estimation". The modelling of coupled circuits presents an excellent precision / calculation time ratio and a good efficiency in the representation of spatial-temporal phenomena. Integrating a winding fault requires changing the model's circuit equations. In order to achieve the objective of this thesis, the structure of the model has been modified to introduce the short circuits between turns at the stator. Apart from the application presented, the association of the identification method with the behavioural model allows the rapid production of multiple waveforms, particularly usable in "signal" oriented detection approaches. Finally, from the tool resulting from the previous work, the diagnostic process could be determined. The detection sensitivity is the main criterion for the definition of the instrumental technique and the signal processing of the process. The influence of the operating conditions on the detection sensitivity is evaluated and is considered for the choice of the solutions adopted. This process has been validated experimentally on a synchronous alternator with wound rotor of 5.4KVA.
Didier, Gaëtan. "Modélisation et diagnostic de la machine asynchrone en présence de défaillances." Nancy 1, 2004. http://www.theses.fr/2004NAN10163.
Full textIn this study, we move on to the broken rotor bar diagnosis of squirrel-cage induction machines. The first part is devoted to the development of a model which is based on the magnetically coupled electric circuits. We present three methods allowing detection of a rotor defect of an induction machine. The first method is based on the evaluation of several indexes calculated starting from the amplitude of the components present in the spectra of the instantaneous power and the line current. The second method of detection suggested uses the stator current spectrum phase calculated starting from a Fourier Transform. To improve the detection, we use the Hilbert transform phase calculated starting from the stator current spectrum module. These approaches have the characteristic to be based on any threshold of reference to establish the presence of a broken rotor bar
Casimir, Roland. "Diagnostic des défauts des machines asynchrones par reconnaissance des formes." Phd thesis, Ecole Centrale de Lyon, 2003. http://tel.archives-ouvertes.fr/tel-00139706.
Full textLebaroud, Abdesselam. "Diagnostic des défauts des machines asynchrones : approche signal et système." Lyon 1, 2007. http://www.theses.fr/2007LYO10288.
Full textThe main piece of the electrical training systems is the induction machine which, during the last three decades, made the object of numerous researches orientated mainly toward the conception of order laws always more competitive. Its numerous qualities, its weak cost, its robustness and its performances make a machine particularly appreciated in industrial middle. The imperatives of reliability and productivity of installations require the incorporation of a system of detection and diagnosis of faults. It is therefore necessary to endow the induction machines of monitoring tools; so we shall be able to avoid faults and untimely stopping. In our step for the faults diagnosis of the induction machine, two approaches have been developed: the first one consists in implementing techniques and methods of treatment and analysis of the signal making facilitating the visual interpretation of the faults and possibly its implantation in a monitoring system. The second approach is said "system" based on tools of classification, in this case Time - frequency Representation (TFR) linked to a decision criterion based on the distances Mahalanobis. The TFR serves to the extraction of the appropriate points which separate maximally, according to the Fisher criteria, two states: one healthy and the other in fault. Nevertheless the choice of points is appraised, what makes this method semi automatic. The association TFR - HMM (Hidden Model of Markov) allows the complete automation of the diagnosis procedure of the faults since the acquisition and the data processing until the decision making
Assaf, Talal. "Contribution à la détection des défauts électriques dans une machine à induction basse tension." Amiens, 2004. http://www.theses.fr/2004AMIE0401.
Full textPetropol, Siana-Elena. "Ondelettes et diagnostic : application aux défauts diélectriques et électriques des machines tournantes." Grenoble INPG, 2001. http://www.theses.fr/2001INPG0077.
Full textThe purpose of this work is the diagnosis of dielectric and electric faults of electrical drives, more precisely, the diagnosis of changes or anomalies in the measured signals. By its time-frequency localization, the Multiresolution Analysis is adaptable to fault diagnosis. He choices of the mother wavelet and of the number of decomposition levels are the freedom degrees, which allow this method to extract relevant information from the analyzed signals. Its implementation by numerical filters reduces the computations cost. The fault detection method computes on-line the wavelet coefficients. A gradual alarm rate is delivered function of the fault type and persistency. The fault isolation and identification methods take into account the spectral contents of the coefficients vector at each decomposition level to determine the fault membership of a class of known fault types and further to estimate the fault amplitude. New classes of faults may be created. The fault detection method has been initially conceived to detect the insulation quick aging and has been further validated for the asynchronous motor parameter fault detection. The fault isolation and identification methods have been developed and verified only for the asynchronous motor application. The Multiresolution Analysis freedom degrees confer flexibility to the developed methods with regard to different applications
Hedayati, Kia Shahin. "Méthodes avancées de traitement du signal pour la détection de défauts électriques et mécaniques dans les machines à induction : Application aux systèmes de traction ferroviaire." Amiens, 2009. http://www.theses.fr/2009AMIE0116.
Full textThe monitoring and diagnosis of the electrical and mechanical faults in railway traction systems have been studied in this dissertation. The railway traction system works in complex condition in which traditional techniques of signal processing cannot be used intensively. Initially, different methods such as non-parametric, parametric and subspace techniques have been examined and finally a method based on MUSIC (MUltiple SIgnal Classification) has been proposed to improve diagnosis of broken bar fault in induction machine, by detecting a large number of frequencies in a given bandwidth. This method is called zoom-MUSIC. The broken bar fault diagnosis in induction machines needs the speed information in order to localize the side-band frequencies around the fundamental in the stator current spectrum. The accurate slip estimation needs also advance signal processing. This fact has been used to define a new technique of broken bar fault detection based on discrete wavelet transform without slip estimation. The non-invasive techniques for mechanical system monitoring are interesting alternatives leading to low cost diagnosis systems. In this way, a theoretical framework has been proposed to show all the effects of a gearbox-based mechanical system torsional vibration on mechanical torque and then on the stator current of the driving machine. This study has been carried out with a basic modeling approach based on the realistic dynamic behavior of a healthy gearbox to show the influence of transmission error, eccentricities of pinion/wheel and teeth contact stiffness variation in the electromagnetic torque and the stator current signatures. In order to test the effectiveness of proposed methods under healthy and faulty mechanical conditions, a unique reduced-scale set-up based on a real railway traction system has been realized and instrumented. The diagnostic methods validated in this reduced-scale, will be in the near future implemented in a scale 1 industrial experimental set-up
Alattass, Mohamed. "Maintenance des machines tournantes : signature de défauts d'engrenages droits et hélicoïdaux." Lyon, INSA, 1994. http://www.theses.fr/1994ISAL0109.
Full textRotating machines deterioration, that are accidental (rupture of a component) or resulting from wears of mechanical elements, are in general very complex. The appearance of deterioration gives rise to a modification of the machine behaviour and especially a vibration level change. This work is a contribution to condition and monitoring and maintenance of gearbox. It consists in studying the effect of some defects by a statistical and morphological identification of the vibrations signals in different domains (time, frequency and wavelets domains). Those signals are collected on an industrial test rig. This work deals first with the experimental simulation of some faults existing on spur and helical gears, and the study of the effect of design and fabrication parameters contact ratio, tooth correction, …) or of the operating conditions (speed and torque) on the dynamic behavior (noise and vibration). Then, by the use of the statistical design procedure, a number of statistical parameters permitting to detect those faults are chosen. Finally, the identification of type of faults have been undertaken from the statistical study of wavelets coefficients
Rouached, Bouali. "Contribution à la modélisation des défauts de bobinages des machines électriques et à leur détection par des mesures au rotor." Doctoral thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69310.
Full textThis thesis deals with the detection of stator winding faults in electrical machines containing a damping structure. Short-circuits between turns of the same winding are often the premise for the appearance of other winding faults, the consequences of which are more severe. Early detection is therefore essential to preserve machines and their human or material environment. In this book, we propose an innovative solution to short-circuit discrimination based on the redundancy of signals measured at the rotor. To define this, high-order modelling combining the finite element approach and that of coupled circuits was used. The first is used to determine the parameters (magnetic couplings) exploited by the second which is none other than the behavioural model. As the downside of this combination of approach is the time taken to identify magnetic couplings and the knowledge that various coil configurations must be modelled, a new identification methodology was developed. After an initial identification (finite elements) at short notice, this offers the possibility of estimating the parameters of adesired winding configuration without reusing the finite element resolution. In addition to its use to implement the detection method presented, this identification methodology is a generator of useful parameters for detections based on "parametric estimation". The modelling of coupled circuits presents an excellent precision/ calculation time ratio and a good efficiency in the representation of spatial-temporal phenomena. Integrating awinding fault requires changing the model's circuit equations. In order to achieve the objective of this thesis, the structure of the model has been modified to introduce the short circuits between turns at the stator. Apart from the application presented, the association of the identification method with the behavioural model allows therapid production of multiple waveforms, particularly usable in "signal" oriented detection approaches. Finally, from the tool resulting from the previous work, the diagnostic process could be determined. The detection sensitivity is the main criterion for the definition of the instrumental technique and the signal processing of the process. The influence of the operating conditions on the detection sensitivity is evaluated and is considered forthe choice of the solutions adopted. This process has been validated experimentally on a synchronous alternator with wound rotor of 5.4KVA.
Bazine, Imène. "Identification en boucle fermée de la machine asynchrone : application à la détection de défaut." Poitiers, 2008. http://theses.edel.univ-poitiers.fr/theses/2008/Ben-Ameur-Bazine/2008-Ben-Ameur-Bazine-These.pdf.
Full textThis thesis presents the application of a closed loop identification technique to induction machines, including explicitly the control algorithm. Basically, direct identification is asymptotically biased by output disturbances and noises which are feedback to the control input via the control algorithm. In order to get rid of this bias problem, an indirect identification technique with explicit use of the controller is proposed. Moreover, a prior knowledge of the control algorithm is replaced by its identification with the help of an overparametrized least squares techniques, which avoids knowledge of the structure and the parameters of the controller. An equivalent minimal structure controller is estimated thanks to an original criterion based on discrete moments. The identification of induction machines is performed with this equivalent controller using an output error technique. Comparative studies performed by Monte Carlo simulations have exhibited bias rejection and better precision of indirect identification, while necessary excitation is only provided by torque variations of the machine load. Finally, this new closed loop identification technique has been applied to the diagnosis of induction machines, with the benefit of better detection of stator and rotor faults, thanks to better rejection of false alarms
Yazidi, Amine. "Contribution au développement de méthodes de détection des défauts électriques dans les machines à induction doublement alimentées pour aérogénérateurs." Amiens, 2006. http://www.theses.fr/2006AMIE0608.
Full textAndriamalala, Rijaniaina Njaksasoa. "Modélisation du défaut d'excentration dans une machine asynchrone : application au diagnostic et à la commande de deux machines spécifiques." Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10064/document.
Full textThis thesis investigates various fault and detection issues in a Dual-Stator Winding Induction Machine Drive including rotor eccentricity problems and inverter switch faults. In addition, the control of six-phase series-connected two-motor drives and the related fault detection and fault tolerant strategy issues are studied as well. The work starts with new modeling methods for an eccentric multiphase induction machine. The first proposed method considers only the winding harmonics and neglects the slotting effects. Then, a second method is proposed, considering the first winding harmonic and the slotting ones. From both modeling techniques, eccentricity signatures are extracted. Simulation results show that both modeling techniques provide identical spectra at low frequency; however, the second technique gives additional high frequency sidebands. These sidebands are the results of the interaction between the eccentricity and the slot harmonics. Eccentricity and inverter faults in a Dual-Stator Winding Induction Machine Drive are subsequently investigated. The inverter topology and the control algorithm are reconfigured to deal with short-circuit and open circuit faults on the inverter side so that the stator currents become balanced again and reach their pre-fault magnitude. Simulation results show promising results. The speed is stabilized after a short disturbance due to the fault. Besides, analytical method has been successfully used to predict eccentricity fault, although the machine was inverter fed. Control variables have been effectively used as diagnosis tools for eccentricity fault in a vector controlled machine. Additionally, decoupled control of six-phase and three-phase machines connected in series has been investigated. Firstly, decoupling control using analytical method is predicted. Several simulations are then carried out to confirm the decoupling effectiveness. For this special drive, elimination of the disturbances due to a switch fault is also possible thanks to an appropriate converter topology and adaptation of the control algorithm. Most of simulation predictions are confirmed by experimental results
Ceban, Andrian. "Méthode globale de diagnostic des machines électriques." Thesis, Artois, 2012. http://www.theses.fr/2012ARTO0202/document.
Full textThe work described in this thesis proposes new procedures to diagnose faults in AC machines. The diagnostic procedures described are reliable, original, inexpensive and simple to implement. They have the advantage of being noninvasive and just get rid from the main drawback presented by other diagnostic methods based on a comparison with a healthy state assumed to be known. The analysis focuses on the magnetic field dispersion in the vicinity of the machine, especially its radial an axial distribution which presents different sensitivity according to various faults. To this end, the phenomena due to inter-turn short-circuit faults in the stator winding, rotor eccentricity and broken rotor bars, are studied in the case of an induction machine and a synchronous machine. For each fault, specific signatures are identified and justified by analytical modeling and numerical method of analysis including coupled electric circuit and finite element methods. Defects have been created in the rotor and stator on different machines in order to validate experimentally the suggested diagnostic procedures
Maatar, Mohamed. "Contribution a l'analyse du comportement dynamique de réducteurs à engrenages simple étage : influence des écarts de forme et des défauts de montage." Lyon, INSA, 1995. http://www.theses.fr/1995ISAL0028.
Full textA systematic approach for analyzing the contribution of shape deviations and mounting errors on gear dynamics is proposed. Co1_1tact conditions for bath rigid and deformable solids are used for defining the excitations of the gear unit. A three dimensional lumped parameter non linear dynamic model with a foundation model for tooth contacts is set up. The contact problem and the equations of motion are simultaneously solved using an original iterative method combining a time step integration and a normal contact algorithm. Comparisons with some experimental evidence and several results of the literature illustrate the interest and the versatility of the procedure. The model is sued for characterizing the influence of shape defects and mounting errors such as flank undulations, tooth spacing errors, eccentricities and misalignment on tooth loads and transmission errors. The role of tooth profile modifications is carefully analyzed, it is demonstrated that long reliefs can substantially improve spur and helical gear dynamic behavior on a given load range. Finally, it is shown that inevitable defects and det1ections of the geared unit may strongly reduce the expected gain in dynamic transmission error
Leboeuf, Nicolas. "Contribution à l'étude des machines synchrones à aimants permanents en présence de défauts inter-spires : modélisation, détection de défauts inter-spires." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0364/document.
Full textEmbedded electric systems in aircraft applications have to satisfy to specifications including weight, performances and reliability leading to the use of Permanent Magnet Synchronous Machines (PMSM). Due to these constraints, prototypes are often different from classical PMSM. Online monitoring of these systems is challenging but is still important regarding safety applications (electro mechanical airfoil, braking?). The main aim is to detect major incidents in order to use redundant systems. This work concerns modeling of PMSM under both healthy and inter-turn fault cases in order to defined online fault detection methods without additional sensors. Two approaches are presented and compared to experimental tests concerning PMSM under inter-turn fault conditions. One of them is based on Permeance Network (PN) modelling. It can be considered to be the best compromise. The next part deals with two fault indicators methods based on healthy models of Inverter and PMSM and shows improvements brought by these approaches compared to classical methods. The whole indicators are analyzed using Pattern Recognition (PR)
Cuevas, Salvatierra Mauricio Andrés. "Méthodes non-invasives de diagnostic de défauts et d'analyse thermique des machines synchrones à pôles saillants." Thesis, Artois, 2017. http://www.theses.fr/2017ARTO0209/document.
Full textThis work aims to develop non-invasive monitoring techniques on AC rotating machines so that their implementation is easy in an industrial environment. For this purpose, two independent methods are described: a fault diagnosis in alternators connected to the local power gird and an exploratory study to evaluate the internal temperature of AC rotating machines.The first method relies on the analysis of two physical magnitudes: the stray magnetic field radiated outside from the external frame and the vibrations content of machine structure. Mathematical models have been developed in order to correlate magnetic and mechanical phenomena which occur in three different machine states: healthy and in two winding short-circuit faults both in the stator and in the rotor. These results were then validated experimentally in laboratory as well as on large machines in industrial environment. A first diagnostic prototype is presented capable to be implemented in industrial environment in order to detect short-circuit faults in larges alternators.In a second time, a temperature estimation method is proposed based on observations concerning variations in material characteristics of windings as temperature increases. Thus, the localizations of impedance resonant frequencies are impacted, which was verified experimentally as well.This thesis work allowed to verify diagnostic feasibility and on-line monitoring methods in rotating machines in a non-invasive way in industrial environments
Ibrahim, Ali. "Contribution au diagnostic de machines électromagnétiques : exploitation des signaux électriques et de la vitesse instantanée." Saint-Etienne, 2009. http://www.theses.fr/2009STET4004.
Full textThis thesis adresses the diagnosis of the mechanical faults of the electromechanical machines by treatment of the power supply (currents and voltages). The main aim is to extract and separate the various components, electric or mechanical, which exist. By modeling the asynchronous machine and the bearing defect, we try to explain the impact of the fault, characterized as cyclostationary process, on the operating mode of the machine. The signal processing tools dedicated to the cyclostationary process can bring a new solutions. We propose to combine these tools and the traditional approaches to extract a useful information from a noisy signal or to extract the mechanical informations from the electric signals and vice versa. To validate the studies of the electrical signals, we also treat the vibratory signals. It is necessary to follow the influence of the defect throughout the driveline and to study the propagation of mechanical faults on the electric variables in the electrical machine. Modeling indicates that the transfer goes through the speed, it is then important to verify the presence of information relating to the fault on the speed signal. Bearing defects are targeted and we propose some ways to use instantaneous speed of the machine as an indicator of failure
Mahyob, Amin. "Modélisation des machines électriques tournantes défectueuses par la méthode des réseaux de perméances : application à la machine asynchrone." Le Havre, 2009. http://www.theses.fr/2009LEHA0017.
Full textFault diagnosis in electrical machines needs a modelling approach reliable and as close to the reality as possible. It is shown that by proper modelling of the electrical machines it is possible to detect the effect of the different faults on the different machine quantities. This work proposes a robust modular model based on Permeance Network Method (PNM) for the diagnosis of induction machine stator and rotor faults. The proposed model allows taking into account the local magnetic saturation of the magnetic circuit due to heavy fault currents, especially in the case of inter-turn short circuit fault, and remains moderately time consuming. In this model, the magnetic circuit of the machine was represented by a set of permeances (reluctances); their values vary as functions of the magnetic state of the machine. Firstly, the system of algebraic equations describing the developed permeance network is written. Then, this magnetic model is coupled to the electrical and mechanical differential equations describing the induction machine operation in presence of different faults to achieve a final system of algebro-differential equations of first order with variable coefficients whose numerical solution is provided by the iterative Newton-Raphson method. The comparison between the experimental results and simulation results obtained by the proposed model in the presence of inter-turn short circuit fault shows the relevance of the chosen method to identify the signature of this fault in the measurable quantities
El, Tabach Mario. "Diagnostic de défauts mécaniques dans les machines tournantes par analyse des signaux électriques d'alimentation." Compiègne, 2004. http://www.theses.fr/2004COMP1502.
Full textRastegar, Fatemi Mohammad Javad. "Détection des défauts mécaniques dans les entraînements électromécaniques complexes : application aux systèmes de levage." Amiens, 2011. http://www.theses.fr/2011AMIE0113.
Full textAs part of predictive maintenance and safe operation of electromechanical systems, the objective of this thesis is to propose some methods for diagnostics and monitoring of mechanical faults. In this work, these methods have been proposed and applied for predictive maintenance in a hoisting winch system driven by an induction machine. The monitoring and fault detection of complex electromechanical systems by using non-invasive sensors is an interesting approach due to simplicity of implementation and its level of reliability. It can be performed with minimal changes for the implementation. The stator current or the stray flux signals can detect the electromechanical faults by non-invasive measurements. The proposed methods do not use these types of sensors. Hence, we have been analyzed these types of sensors for the study of mechanical faults. For an application where the stator current is not available, another alternative using the stray flux of the machine has been considered for the system condition monitoring. In this thesis, five new diagnostic methods have been proposed and have been presented with their experimental results. A method using the stray flux is proposed to monitor the gearbox. It is based on the stator current signature, which directly affects the stray flux. Other mechanical parts of an electrical machine like bearings and the rotor shaft eccentricity are monitored by the stray flux in comparison to the stator current. It is also verified the influence of the load on the output torque and on the stator current in case of the planetary gearbox and misalignment faults in a hoisting winch system. A novel non-invasive method has been presented to detect defective conditions of the wire rope of a hoisting winch system using the stator current and the output torque of an induction machine. In addition, an other non-invasive method has been presented for detection of the hanging load effect in the stator current and the output torque
Laouti, Nassim. "Diagnostic de défauts par les Machines à Vecteurs Supports : application à différents systèmes mutivariables nonlinéaires." Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00985437.
Full textFourati, Aroua. "Modélisation électro-magnéto-mécanique d'une machine asynchrone sous approche angulaire : Application au diagnostic des défauts de roulements en régime non stationnaire." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI078.
Full textIn an induction machine, the diagnosis of defects by analysis of the electrical current signal requires knowledge of the dynamic behavior of the machine. In addition to external excitation sources, the behavior of the motor is governed by a set of periodic phenomena related to its angularly periodic geometry and coupled by their multiphysical character. In the presence of a bearing defect, measurable quantities will have components at its characteristic frequency combined with the characteristic frequencies of the engine. The understanding of interactions, in particular modulation, requires the implementation of numerical models that represent the manifestations of coupled phenomena. This thesis work proposes an electro-magneto-mechanical model of a squirrel-cage induction machine coupled to a rolling bearing model in an original writing frame called "Angular Approaches". By keeping the "Angle-Time" relation in modeling, it is possible to easily extend the modeling to non-stationary operating conditions and to introduce a strong coupling between the mechanical and electromagnetic models. Thus, it is shown that the instantaneous angular speed is the quantity which ensures the transmission of the localized mechanical defect to the electrical quantities. The proposed model thus offers a decryption of the modulation phenomena present on the transfer path and described by the couplings of cyclic dynamic behaviors (permeance network, loading of the rolling elements, etc.) and / or periodic (structural resonances, electrical resonance, etc.). This work opens the way for a better understanding of the multiphysical coupled behaviors of an electrical machine to better specify the monitoring tools to be used. Further developments can now be directed to a complexity of models or to the exploitation of fine dynamic behaviors in a non-steady operating conditions
Velly, Nicolas. "Contributions à l’étude de machines multi-enroulements pour l’aéronautique : machine synchrone à aimants permanents pour la tolérance aux défauts : machine asynchrone pour la traction." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL022N/document.
Full textThe more electrical aircraft project aims at replacing most of current power generation sources by electrical ones. Consequently this replacement might generate a significant decrease of the fuel consumption. Through this thesis we determine two electrical solutions allowing on the one hand the increase of disponibility level of the actuators and on the other handthe aircraft taxiing by electrical means. We firstly focused on electrical actuators that require electrical redundancy. A first mean to achieve this redundancy is to use two actuators. Nevertheless this solution is not relevant under the reliability constraint because the global failure rate is increased. A double star permanent magnet synchronous motor with concentrated winding is proposed in which a special care was taken to the short circuit current limitation and the magnetic decoupling between the two star winding. We established a semi-analytic model for this kind of motors to predict the amplitude of the resultant of the radial forces acting on the rotor of the machine when operating under normal and faulty operation. We established the model of the machine in order to determine the command strategy. We experimentally validated all of the design principles mentioned above through a prototype designed in the laboratory and built by one of the SAFRAN group company. We secondly investigated on the way to apply the multi winding principles to a brand new project linked to the aircraft taxiing called “green taxiing”. The goal is to obtain a motor topology that allows operating on a wide speed range thanks to the command strategy and the change of its torque coefficient. We established the model of the machine and we compared the results given by this ingenious model to the results given by a finite element resolution using a transient magnetic application
Lazarus, Arnaud. "Influence des défauts sur le comportement vibratoire linéaire des systèmes tournants." Phd thesis, Palaiseau, Ecole polytechnique, 2008. http://pastel.archives-ouvertes.fr/pastel-00004939/en/.
Full textSalles, Gaël. "Surveillance et diagnostic des défauts de la charge d'un entraînement par machine asynchrone." Lyon 1, 1997. http://www.theses.fr/1997LYO10017.
Full textBoileau, Thierry. "Contribution à la continuité de service des actionneurs synchrones à aimants permanents. Tolérance au défaut de capteur mécanique. Détection de Défauts Electriques." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL068N/document.
Full textIn embedded systems, electric actuators tend to replace hydraulic ones for compactness and manoeuvrability reasons. However, these electric actuators should be as reliable as hydraulic ones. For these actuators, adapted power topologies should be chosen in order to operate even if a failure occurs in the electromechanical conversion chain. To ensure the continuity of service in fault case, different kinds of actuator’s failures should be detected in time. Obviously, the detection methods should be adapted to the fault types. In this work, we developed two aspects related to the continuity of service, the first one on the sensorless control of permanent magnet synchronous machines (PMSM), its robustness and its application in mechanical sensor loss case. The second one deals with the detection of inter-turn insulation fault in stator windings of permanent magnets synchronous machines supply by voltage inverter. In a first time a PMSM model with inter-turn fault is developed, this model allows us to propose two detection methods. Both methods are based on the electric unbalance of the machine and are experimentally validated. Finally a third method based on resistance estimation is presented. These three methods are real time methods and no extra sensor is needed for a standard control
Abed, Aïcha. "Contribution à l'étude et au diagnostic de la machine asynchrone." Nancy 1, 2002. http://www.theses.fr/2002NAN10020.
Full textUsed in the majority of the electric drives, the asynchronous machine tends to supplant the machine with D. C. Current as well as the synchronous machine because of its many qualities, and mainly of its low cost and its robustness. Thus, a general reflexion is committed in modeling and diagnostic of induction machine defects. More particularly, we propose to study the rotor defects (broken bars in the rotor). In the first time, we develop two models of the asynchronous machine for the simulation of broken bars. We present in the continuation three methods to detect this fault. The principle of detection is based on the spectral analysis of the stator current in order to follow the evolution of the frequencies which are related to the fault. Lastly, a study of the defect in the presence of a classical vector control is presented, opening a new way towards a diagnostic in the case of speed variation. An experimental part is carried out to validate the exactitude of the theoretical results and to show the effectiveness of the developed methods
Raad, Amani. "Contributions aux statistiques cycliques d'ordre supérieur : applications au diagnostic des défauts d'engrenage." Compiègne, 2003. http://www.theses.fr/2003COMP1471.
Full textThe aim of this thesis is vibration and Acoustic Emission (AE) analysis in rotating machinery for monitoring and diagnosis of their gear fauIts. The first section is concerned with the potential of the AE technique by giving a comparison with vibrations. We show the complementarity between the two techniques to give a better diagnosis. Simples descriptors are extracted as kurtosis. The second part is more concerned with a generic modelling of geaI signaIs. This modelling helps to demonstrate the higher order cyclostationarity of gear signàls. We expose after the theory of cyclic bispectrum, third-order statistical too1. We propose at the end simple and concise cyclostationary indicators. Several applications to industrial gear signaIs are illustrated
Houdouin, Gilles. "Contribution à la modélisation de la machine asynchrone en présence de défauts rotoriques." Le Havre, 2004. http://www.theses.fr/2004LEHA0001.
Full textThis study makes it possible first to point out the formulations of the magnetomotive forces, of the air-gap permeance and flux density, and to deduce their harmonic contents with precision. It also makes it possible to quantify the rotor faults influence on the harmonics of the stator currents, power and electromagnetic couple. The contributions of this work are : an original modeling of a doubly slotted air-gap permeance, taking into account the geometry of the slots ; the calculation of the mutual inductances and their derivatives, and their numerical handling, allowing a very good computing time to precision ratio ; the development of a dedicated software, based on an algorithm using a variable topology strategy which allows an automatic adjustment of the dimension of the machine equations system. The simulation results have been helpful to study the faults signature in the main quantities of the machine. These results have been in a good concordance with the experimental results
Ben, Attia Houda. "Détection et localisation de défauts mécaniques d'un entraînement électrique à vitesse variable." Toulouse, INPT, 2003. http://www.theses.fr/2003INPT012H.
Full textBreneur, Claire. "Eléments de maintenance préventive de machines tournantes dans le cas de défauts combinés d'engrenages et de roulements." Lyon, INSA, 2002. http://theses.insa-lyon.fr/publication/2002ISAL0096/these.pdf.
Full textMachinery used in industrial and transport domains have to be more and more efficient. So, the maintenance of such systems is very important. Interventions must only happen in presence of real damage, and the diagnostic must be reliable and easy to read. This work gave a new elements about the diagnostic of gears power transmissions in case of combined faults of gears and bearings. Gear and bearing faults have been artificially created on an experimental set-up. Transmission error and the bearings accelerations were measured for different operating conditions. Result analysis showed that accelerations envelope signal is an efficient tool for bearings diagnostic, for all operating conditions even in the presence of other defective mechanical components. Moreover, we showed that only accelerations measured in the vicinity of the defective bearing produce a significant pattern of fault presence. According to literature, accelerations analysis produce reliable information about gears health. Yet, we showed that such results are only valid in the case of bearings without any fault. In the presence of simultaneous bearing and gear faults, the transmission error appears as an useful tool giving supplementary information about the gear faults. The obtained results and the established indicators lead to an efficient diagnostic process applied on gear power transmission systems. Moreover, automation of maintenance preventive has been assessed, using neural networks, the used approaches seem to be efficient for the automation procedures, and provides a powerful tool for the optimisation of established indicators
Fedida, Vincent. "Etude des défauts des machines électriques tournantes par analyse du champ magnétique de fuite : Application au diagnostic de machines de faibles puissances dans un contexte de production en grande série." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT023.
Full textDiagnostic and identification of defaults providing in electrical machines (mainly single phased asynchrone motors) by stray flux measurement
Cardenas, Cabada Edouard. "L'imagerie acoustique au service de la surveillance et de la détection des défauts mécaniques." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI124/document.
Full textVibration analysis is mainly used in condition monitoring and fault detection of rotating machine domain. The success of the diagnosis is strongly related to the position of the accelerometers. However, the machine geometry sometimes prevents the sensors to be placed close enough to the faulted part causing the diagnostic failure. The sound emitted by a mechanism and its condition are related. Using microphones to optimize condition monitoring is then justified. Acoustic imaging techniques (acoustic holography, beamforming, etc…) are mainly used as a source localization and quantification tool but they can be turned into a powerful diagnosis tool. Several strategies based on the beamforming algorithm are developed in this work. Firstly, diagnosis features commonly used in condition monitoring of rotating machinery are mapped as a function of space. Kurtosis allows localizing impulsive sources which eventually can be related to a mechanism failure. New features based on the squared envelope spectrum of the focused signals are also introduced. They aim toward the detection of inner and outer race fault in roller element bearings. On the other hand, angular synchronous average is used to extract the acoustic field synchronous with one component rotation. The sources related to a fault are localized in the residual field mappings. Finally, a new imaging technique based on the vibroacoustic transfer functions between a few accelerometers placed on the machine and the microphone array is developed. It allows obtaining the mappings of the radiated pressure on the machine surface only thanks to the accelerometers. It is tested as a fault detection tool on a test bench
Lazarus, Arnaud. "Influence des défauts sur le comportement vibratoire linéaire des systèmes tournant." Phd thesis, Ecole Polytechnique X, 2008. http://tel.archives-ouvertes.fr/tel-00370228.
Full textEn étudiant les solutions de Floquet dans le domaine fréquentiel, on montre que l'on peut étendre le principe d'analyse modale des oscillateurs classiques aux oscillateurs paramétriques. Le concept de modes propres paramétriques est alors introduit et ceux-ci sont étudiés à travers différents exemples académiques. On s'intéresse notamment au comportement dynamique du pendule paramétrique à un degré de liberté gouverné par l'équation de Mathieu, ainsi qu'à différents systèmes tournants à 2 degrés de libertés avec raideurs non axisymétriques (modèles simplifiés de rotors fissurés).
A l'image des modes classiques, les modes paramétriques peuvent être étendus aux systèmes complexes discrétisés par n degrés de liberté grâce aux éléments finis. Cependant, ces modes étant poly-harmoniques, on obtient la base modale du système par synthèse modale où chaque sous-structure est naturellement associée à chaque harmonique. Ces idées sont implémentées dans le logiciel éléments finis Cast3m afin de modéliser, en 3D, le comportement vibratoire d'ensemble d'une machine tournante avec un défaut de forme. L'efficacité de la méthode est alors testée en comparant les résultats numériques et expérimentaux provenant d'un banc d'essai composé d'un rotor dissymétrique en rotation sur un support anisotrope (modèle académique d'un rotor avec fissure ouverte).
Ali, Abdallah Ali. "Modélisation des machines synchrones à aimants permanents pour la simulation de défauts statoriques : application à la traction ferroviaire." Toulouse, INPT, 2006. http://www.theses.fr/2006INPT033H.
Full textRotating electrical machines play a very important role in the world's industry. Among them, the permanent magnet synchronous machines are more and more used because of their high power to weight ratio, their great efficiency and the recent affordability of magnet materials. Permanent magnet synchronous machines are also more and more envisaged in high power applications ( railway applications for instance). In this context, these machines can be submitted to external and internal stresses, and degradation can occur in their electrical and mechanical parts. This is why industry is interested in adopting monitoring and diagnosis techniques to assess and evaluate condition of these machines. The modelling of surface-mounted permanent magnet synchronous machines with stator faults takes place in this context
Bachir, Smaïl. "Contribution au diagnostic de la machine asynchrone par estimation paramétrique." Poitiers, 2002. http://www.theses.fr/2002POIT2306.
Full textEl, Bouchikhi El Houssin. "Sur l'estimation spectrale paramétrique pour la détection des défauts dans les machines asynchrones en environnements stationnaire et non stationnaire." Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-01019643.
Full textDiouf, Saliou. "Contribution au diagnostic industriel de défauts de roulement et de balourd par techniques neuronales : application à la machine asynchrone à cage." Paris 12, 2007. http://www.theses.fr/2007PA120024.
Full textThis thesis is focused on vibratory signatures based faults detection and classification aiming computer aided diagnosis of defects relative to umbalanced rotation or dealing with rolling bearing's external ring's chipping defects appearing in turning machines. It relates the use of neural techniques for detection and computer aided diagnosis of such defects. We develop two approaches starting from the vibratory signatures obtained for the first one from a current sensor, and for the other one from an accelometer-like sensor. These signatures are initially pre-processed by PCA and after that they are classified by an artificial neural network (ANN). We use two types of neural classifiers, known for their classification capabilities : RBF and LVQ. The validation of these two approaches is carried out through the study of the pre-processing of the signatures and the parameters of different ANNs, using an experimental asynchronous electromotor
Al-Ahmar, Elie. "Comparaison de différentes méthodes avancées de traitement de signal pour la détection et le diagnostic de défauts dans les machines asynchrones : application aux éoliennes." Brest, 2010. http://www.theses.fr/2010BRES2054.
Full textFault detection and diagnosis play a vital role in industry. In fact, they help invested capitals to earn production and availability points in the production process. The increasing interest of different industrial sectors and the research domain clearly show that fault detection and diagnosis is a very promising niche. In recent years, many techniques have been developed for detecting faults in electric machines; among them stator current-based signal processing techniques mainly for induction motors. This PhD thesis have been therefore focused on an analysis and then a comparison study of advanced signal processing techniques for fault detection and diagnosis in induction machines used in wind turbines. First a state of the art presenting different type of energies (fossils and renewable) allowed to highlight wind energy importance. Then, a brief presentation is given on main faults in induction machine-based wind turbines. This has allowed the introduction of different advanced signal processing techniques for a wind turbine application and therefore has highlighted the main limitations of the already used techniques for the motor application. Knowing the stator current nonstationary nature (wind turbine operation and fault occurrence), it has then be proceeded to test specific techniques such as time-frequency and wavelets, These techniques were then used to build-up a Matlab-Simulink®-based tool devoted to the condition monitoring of a wind turbine induction generator
Lanciotti, Noemi. "Amélioration de la robustesse des machines synchrones spéciales multi phases dans un contexte de transport urbain." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN055/document.
Full textFive-phase flux switching machines have a fault tolerance and robustness that makes them very interesting from the point of view of reliability, as shown in chapter one of this work. In our studies we have explored the possibility of detecting faults that affect this type of machine using the signature of stator vibrations.Using the physical and mathematical tools presented in chapter two, we improved two multyphisics models, one based on finite elements method that it's presented in chapter three and the seconde one analitycal model, called permeance networks, in chapter four. The vibratory behavior of the machine was studied using these two models, under healthy and faulty conditions, in order to know how this behavior is influenced by the electrical and magnetic magnitudes of the machine. In addition, we have studied the possibility of detecting and discriminating different types of faults. Analytical model is a good estimator of fault behavior of the machine, despite its differences with the simulation.In chapter five, the two multiphysical models have been validated by experimental tests and we have been able to explain fault behavior by mechanical origin rather than magnetic origin.Finally, in chapter six, we used both models to study the fault behavior of the machine, at speeds above the experimental limit (3100 rpm)
Demian, Cristian. "Détection des défauts rotoriques dans les machines à courant alternatif par capteur de flux de dispersion : application au contrôle qualité des rotors à cage." Amiens, 2005. http://www.theses.fr/2005AMIE0509.
Full textBui, Viet Phuong. "Diagnostic des machines électriques par l'analyse du champ magnétique de fuite : application à l'identification de défauts rotoriques d'un alternateur à vide." Phd thesis, Grenoble INPG, 2007. http://tel.archives-ouvertes.fr/tel-00187238.
Full textJouy, Franck. "Contribution à la modélisation et à l'identification des défauts géométriques des machines à coordonnées : application au contrôle intégré en atelier flexible." Châtenay-Malabry, Ecole centrale de Paris, 1987. http://www.theses.fr/1987ECAP0031.
Full textOumaamar, Mohamed El Kamel. "Surveillance et diagnostic des défauts rotoriques et mécaniques de la machine asynchrone avec alimentation équilibrée ou déséquilibrée." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0022/document.
Full textThe research presented in this thesis concerns the diagnosis of rotor and mechanical defaults of the induction machine. First, there is provided a summary of the diagnostic methods supported by experiments with defects created in the rotor and stator of the asynchronous machine fed from the network. And in the same vein, an experimental study on the comparison in amplitude and phase signatures of defects in bar in the spectra between the stator current and neutral voltage was discussed. In a second step, the induction motor is fed by a converter mounted directly onto the motor. We introduced a new diagnostic technique based on spectral analysis of the currents of the network (upstream of the converter-machine). Finally, in order to simulate the behavior of the machine, it was necessary to develop an accurate model taking into account the space harmonics, and neutral voltage. To corroborate the frequency induced by rotor defects in the neutral voltage, a theoretical study was presented which gave interesting results
Moriere, Stéphane. "Contribution à l'étude des assemblages avec prise en compte des défauts de forme : modélisation et expérimentation." Thesis, Aix-Marseille 2, 2010. http://www.theses.fr/2010AIX22119/document.
Full textPhD in Mechanics of solids
Viprey, Fabien. "Modélisation et caractérisation des défauts de structure de machine-outil 5 axes pour la mesure in-process." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLN071/document.
Full textIn-process metrology consists in obtaining measurement data directly into the manufacturing process. This method results from an increasing need of manufacturers to carry out on-line measurements during one manufacturing task or between two manufacturing tasks by using the mean of production to measure the machined part. Monitoring the sources of errors like geometric errors is one of the prerequisites to ensure the traceable dimensional metrology directly on the machine tool.This thesis deals with the geometric modeling of 5-axis machine tool based on a standardized parameterization of geometric errors. This model is simulated and simplified by the use of a virtual machine developed in order to help understand and visualize the effects of geometric errors on the volumetric error.A new standard thermo-invariant material namely Multi-Feature Bar has been developed.After its calibration and after a European intercomparison, it provides a direct metrological traceability to the SI meter for dimensional measurement on machine tool in a hostile environment. The identification of three intrinsic parameters of this standard, coupled with a measurement procedure ensures complete and traceable identification of motion errors of linear axes. The identification of position and orientation errors of axis is based on an analysis of combinations of necessary parameters to characterize volumetric error and at best. A model parameter identification procedure is proposed by minimizing the time drift of the structural loop and the effects of previously identified motion errors. Asensitivity analysis of the measurement procedure settings and of the noise effects ensures the quality of this proposed identification
Sprooten, Jonathan. "Finite element and electrical circuit modelling of faulty induction machines: Study of internal effects and fault detection techniques." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210674.
Full textMany authors are working in this field but few approach the diagnosis from a detailed and clear physical understanding of the localised phenomena linked to the faults. Broken bars are known to modulate stator currents but it is shown in this work that it also changes machine saturation level in the neighbourhood of the bar. Furthermore, depending on the voltage level, this change in local saturation affects the amplitude and the phase of the modulation. This is of major importance as most diagnosis techniques use this feature to detect and quantify broken bars. For stator short-circuits, a high current is flowing in the short-circuited coil due to mutual coupling with the other windings and current spikes are flowing in the rotor bars as they pass in front of the short-circuited conductors. In the case of rotor eccentricities, the number of pole-pairs and the connection of these pole-pairs greatly affect the airgap flux density distribution as well as the repartition of the line currents in the different pole-pairs.
These conclusions are obtained through the use of time-stepping finite element models of the faulty motors. Moreover, circuit models of faulty machines are built based on the conclusions of previously explained fault analysis and on classical Park models. A common mathematical description is used which allows objective comparison of the models for representation of the machine behaviour and computing time.
The identifiability of the parameters of the models as well as methods for their identification are studied. Focus is set on the representation of the machine behaviour using these parameters more than the precise identification of the parameters. It is shown that some classical parameters can not be uniquely identified using only stator measurements.
Fault detection and identification using computationally cheap models are compared to advanced detection through motor stator current spectral analysis. This last approach allows faster detection and identification of the fault but leads to incorrect conclusions in low load conditions, in transient situations or in perturbed environments (i.e. fluctuating load torque and unideal supply). Efficient quantification of the fault can be obtained using detection techniques based on the comparison of the process to a model.
Finally, the work provides guidelines for motor supervision strategies depending on the context of motor utilisation.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished