http://hdl.handle.net/10985/182 Tue, 21 Apr 2026 04:40:28 GMT 2026-04-21T04:40:28Z https://sam.ensam.eu:443/bitstream/id/b63a4644-a752-42c1-a534-2b41ff2bb590/ http://hdl.handle.net/10985/182 http://hdl.handle.net/10985/16564 Stochastic Metamodel for Probability of Detection Estimation of Eddy-Current Testing Problem in Random Geometric ABDELLI, Djamel Eddin; NGUYEN, Thanh Hung; CHERIET, Ahmed; CLENET, Stephane The calculation of the Probability Of Detection (POD) in Non Destructive Eddy Current Testing requires the solution of a stochastic model requiring numerous calls of a numerical model leading to a huge computation time. To reduce this computation time, we propose in this paper to combine either the use of a stochastic metamodel and a mapping which avoids the remeshing step. The stochastic metamodel is constructed using the Least Angle Regression Method. This approach is tested on a axisymmetric problem with 6 random input paramters which shows its efficiency and its accuracy. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/16564 2019-01-01T00:00:00Z ABDELLI, Djamel Eddin NGUYEN, Thanh Hung CHERIET, Ahmed CLENET, Stephane The calculation of the Probability Of Detection (POD) in Non Destructive Eddy Current Testing requires the solution of a stochastic model requiring numerous calls of a numerical model leading to a huge computation time. To reduce this computation time, we propose in this paper to combine either the use of a stochastic metamodel and a mapping which avoids the remeshing step. The stochastic metamodel is constructed using the Least Angle Regression Method. This approach is tested on a axisymmetric problem with 6 random input paramters which shows its efficiency and its accuracy. http://hdl.handle.net/10985/16565 Exploitation of independent stator and rotor geometrical periodicities in electrical machines using the Schur complement AL EIT, Moustafa; CLENET, Stephane; HENNERON, Thomas; GUYOMARCH, Fréderic In this paper we present a-priori model reduction technique that enables to take full advantage of the periodicity existing in the stator and rotor geometrical structures of electrical machines in order to reduce the computational time. Firstly, a change of basis is performed by applying two distinct discrete Fourier transformations on the stator and rotor periodic structures independently. Secondly, the Schur complement is introduced in the new spectral basis, to allow a parallel solving of the resulting block-diagonal matrix systems. Moreover, the using of a matrix-free Krylov method based on the conjugate gradient solver has verified an efficient solving of the equation system associated to the stator-rotor interface. Furthermore, in the peculiar case of balanced supply conditions, a model order reduction can be carried out by considering only the dominant discrete Fourier transform components. This model reduction approach is applied on a buried permanent magnet machine and has successfully shown its efficiency under balanced and unbalanced conditions. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/16565 2019-01-01T00:00:00Z AL EIT, Moustafa CLENET, Stephane HENNERON, Thomas GUYOMARCH, Fréderic In this paper we present a-priori model reduction technique that enables to take full advantage of the periodicity existing in the stator and rotor geometrical structures of electrical machines in order to reduce the computational time. Firstly, a change of basis is performed by applying two distinct discrete Fourier transformations on the stator and rotor periodic structures independently. Secondly, the Schur complement is introduced in the new spectral basis, to allow a parallel solving of the resulting block-diagonal matrix systems. Moreover, the using of a matrix-free Krylov method based on the conjugate gradient solver has verified an efficient solving of the equation system associated to the stator-rotor interface. Furthermore, in the peculiar case of balanced supply conditions, a model order reduction can be carried out by considering only the dominant discrete Fourier transform components. This model reduction approach is applied on a buried permanent magnet machine and has successfully shown its efficiency under balanced and unbalanced conditions. http://hdl.handle.net/10985/16566 Finite-Element Model Reduction of Surface-Mounted Permanent Magnet Machines by Exploitation of Geometrical Periodicity AL EIT, Moustafa; HENNERON, Thomas; CLENET, Stephane This paper presents a methodology that allows taking advantage of the geometrical periodicity of electrical machines together with the modeling of rotor motion. It enables by means of the discrete Fourier transform (DFT) to reduce the large-scale system obtained from the finite-element model to several smaller independent subsystems, allowing a shortening of the computational time. Due to DFT properties, the computational time can be more reduced especially when we consider the inter-dependence of the spectral components under either balanced or unbalanced supply condition. In addition, a further reduction is possible in the case of balanced regimes where the distribution of the eventual numerical solution is governed by a limited number of prevailing harmonics. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/16566 2018-01-01T00:00:00Z AL EIT, Moustafa HENNERON, Thomas CLENET, Stephane This paper presents a methodology that allows taking advantage of the geometrical periodicity of electrical machines together with the modeling of rotor motion. It enables by means of the discrete Fourier transform (DFT) to reduce the large-scale system obtained from the finite-element model to several smaller independent subsystems, allowing a shortening of the computational time. Due to DFT properties, the computational time can be more reduced especially when we consider the inter-dependence of the spectral components under either balanced or unbalanced supply condition. In addition, a further reduction is possible in the case of balanced regimes where the distribution of the eventual numerical solution is governed by a limited number of prevailing harmonics. http://hdl.handle.net/10985/10300 Laboratory-based test bed of a three terminals DC networks using power hardware in the loop AMAMRA, Sid-Ali; COLAS, Frédéric; GUILLAUD, Xavier; NGUEFEU, Samuel In this paper a three stations MTDC grid is presented, providing a specific application of our work. The experimental platform is intended to combine electrical power components and communication/control equipment with real-time simulation tools. In this way the platform can test grid elements and evaluate different operation scenarios under various conditions. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/10300 2013-01-01T00:00:00Z AMAMRA, Sid-Ali COLAS, Frédéric GUILLAUD, Xavier NGUEFEU, Samuel In this paper a three stations MTDC grid is presented, providing a specific application of our work. The experimental platform is intended to combine electrical power components and communication/control equipment with real-time simulation tools. In this way the platform can test grid elements and evaluate different operation scenarios under various conditions. http://hdl.handle.net/10985/17726 Laboratory Demonstration of a Multiterminal VSC-HVDC Power Grid AMAMRA, Sid-Ali; COLAS, Frédéric; GUILLAUD, Xavier; RAULT, Pierre; NGUEFEU, Samuel This paper presents the design, development, con- trol and supervision of a hardware-based laboratory Multi- Terminal-Direct-Current (MTDC) test-bed. This work is a part of the TWENTIES (Transmission system operation with large penetration of Wind and other renewable Electricity sources in Networks by means of innovative Tools and Integrated Energy Solutions) DEMO 3 European project which aims to demonstrate the feasibility of a DC grid through experimental tests. This is a hardware-in-the-loop DC system test-bed with simulated AC systems in real time simulation; the DC cables and some converters are actual, at laboratory scale. The laboratory scale test-bed is homothetic to a full scale high voltage direct current (HVDC) system: electrical elements are the same in per unit. The test-bed is supervised by a Supervisory Control And Data Acquisition (SCADA) system based on PcVue. Primary control based droop control method to provide DC grid power balance and coordinated control methods to dispatch power as scheduled by transmission system operator (TSO) are implemented. Since primary control acts as converter level by using local measure- ments, a coordinated control is proposed to manage the DC grid power flow. The implemented system is innovative and achievable for real-time, real-world MTDC-HVDC grid applications. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/17726 2017-01-01T00:00:00Z AMAMRA, Sid-Ali COLAS, Frédéric GUILLAUD, Xavier RAULT, Pierre NGUEFEU, Samuel This paper presents the design, development, con- trol and supervision of a hardware-based laboratory Multi- Terminal-Direct-Current (MTDC) test-bed. This work is a part of the TWENTIES (Transmission system operation with large penetration of Wind and other renewable Electricity sources in Networks by means of innovative Tools and Integrated Energy Solutions) DEMO 3 European project which aims to demonstrate the feasibility of a DC grid through experimental tests. This is a hardware-in-the-loop DC system test-bed with simulated AC systems in real time simulation; the DC cables and some converters are actual, at laboratory scale. The laboratory scale test-bed is homothetic to a full scale high voltage direct current (HVDC) system: electrical elements are the same in per unit. The test-bed is supervised by a Supervisory Control And Data Acquisition (SCADA) system based on PcVue. Primary control based droop control method to provide DC grid power balance and coordinated control methods to dispatch power as scheduled by transmission system operator (TSO) are implemented. Since primary control acts as converter level by using local measure- ments, a coordinated control is proposed to manage the DC grid power flow. The implemented system is innovative and achievable for real-time, real-world MTDC-HVDC grid applications. http://hdl.handle.net/10985/8546 Analysis of the energy harvesting performance of a piezoelectric bender outside its resonance AMANCI, Adrien; GIRAUD, Frédéric; AMBERG, Michel; DAWSON, Francis; LEMAIRE-SEMAIL, Betty; GIRAUD-AUDINE, Christophe When the frequency of the source of vibration of a piezolectric generator is significantly different from its eigenfrequency, the dielectric power losses become prominent and decrease the amount of power which is practically harvested. For off-resonance vibrating frequencies, the optimal operating conditions can be obtained with a Maximum Power Point Tracking method. This paper introduces complex phasors in the study of power conversion for piezoelectric generators. These complex phasors are used to describe three strategies which help simplify the tracking of the optimal generator output power for vibration frequencies which are away from resonance. Experimental results obtained on a prototype illustrate and confirm the approach with the phasor approaches illustrate and confirm the success of the proposed optimal power tracking strategies. Finally, we show that the efficiency results of each strategy depend on whether they are used inside or outside a frequency bandwidth around the eigenfrequency, and that the length of this bandwidth depends on the excitation amplitude. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8546 2014-01-01T00:00:00Z AMANCI, Adrien GIRAUD, Frédéric AMBERG, Michel DAWSON, Francis LEMAIRE-SEMAIL, Betty GIRAUD-AUDINE, Christophe When the frequency of the source of vibration of a piezolectric generator is significantly different from its eigenfrequency, the dielectric power losses become prominent and decrease the amount of power which is practically harvested. For off-resonance vibrating frequencies, the optimal operating conditions can be obtained with a Maximum Power Point Tracking method. This paper introduces complex phasors in the study of power conversion for piezoelectric generators. These complex phasors are used to describe three strategies which help simplify the tracking of the optimal generator output power for vibration frequencies which are away from resonance. Experimental results obtained on a prototype illustrate and confirm the approach with the phasor approaches illustrate and confirm the success of the proposed optimal power tracking strategies. Finally, we show that the efficiency results of each strategy depend on whether they are used inside or outside a frequency bandwidth around the eigenfrequency, and that the length of this bandwidth depends on the excitation amplitude. http://hdl.handle.net/10985/16569 Characterization of the Local Incremental Permeability of a Ferromagnetic Plate Based on a Four Needles Technique ARBENZ, Laure; BENABOU, Abdelkader; MIPO, Jean-Claude; FAVEROLLE, Pierre; CLENET, Stephane The performances of electrical machines depend highly on the behavior of ferromagnetic materials. In some applications, these materials operate under DC polarization, i.e. when the magnetic field oscillates around a DC bias. In that condition, it is required to know the incremental permeability which characterizes the magnetic behavior of the material around the operating point. In this paper, a non-destructive approach, involving a combination of experiment and Finite Element (FE) technique, is presented in order to determine the incremental permeability. The proposed sensor is based on the four-needles method. With this sensor, Bowler et al. have proposed a method to determine the initial permeability of homogeneous metal plates based on an analytical model. Here we propose to use the same kind of sensor to determine the incremental permeability. The measurement process is analyzed using a FE model. It is shown that the analytical approach reaches its limits if the permeability of the plate and its thickness become too high. A combination between the measurements and a FE model is introduced to overcome this difficulty to determine the incremental permeability. The study of two magnetic steel samples illustrates the interest of this method. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/16569 2016-01-01T00:00:00Z ARBENZ, Laure BENABOU, Abdelkader MIPO, Jean-Claude FAVEROLLE, Pierre CLENET, Stephane The performances of electrical machines depend highly on the behavior of ferromagnetic materials. In some applications, these materials operate under DC polarization, i.e. when the magnetic field oscillates around a DC bias. In that condition, it is required to know the incremental permeability which characterizes the magnetic behavior of the material around the operating point. In this paper, a non-destructive approach, involving a combination of experiment and Finite Element (FE) technique, is presented in order to determine the incremental permeability. The proposed sensor is based on the four-needles method. With this sensor, Bowler et al. have proposed a method to determine the initial permeability of homogeneous metal plates based on an analytical model. Here we propose to use the same kind of sensor to determine the incremental permeability. The measurement process is analyzed using a FE model. It is shown that the analytical approach reaches its limits if the permeability of the plate and its thickness become too high. A combination between the measurements and a FE model is introduced to overcome this difficulty to determine the incremental permeability. The study of two magnetic steel samples illustrates the interest of this method. http://hdl.handle.net/10985/9861 Characterization of the local Electrical Properties of Electrical Machine Parts with non-Trivial Geometry ARBENZ, Laure; BENABOU, Abdelkader; MIPO, Jean-Claude; FAVEROLLE, Pierre; CLENET, Stephane In electrical machines, knowing the electrical conductivity is of importance for the eddy current calculation, especially when massive iron parts are involved. Generally the conductivity is measured on samples of raw materials with simple geometries. Indeed, a simple geometry is suitable for applying an analytical approach to deduce the electrical conductivity from the measured electrical quantities. Nevertheless, when a non destructive measurement is required, the measurement of the electrical conductivity can become rather difficult on parts with complex geometry. To that end, with the help of the Finite Element Modeling approach (FEM), a strategy is developed to characterize the local electrical properties of parts with a non-trivial geometry. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9861 2015-01-01T00:00:00Z ARBENZ, Laure BENABOU, Abdelkader MIPO, Jean-Claude FAVEROLLE, Pierre CLENET, Stephane In electrical machines, knowing the electrical conductivity is of importance for the eddy current calculation, especially when massive iron parts are involved. Generally the conductivity is measured on samples of raw materials with simple geometries. Indeed, a simple geometry is suitable for applying an analytical approach to deduce the electrical conductivity from the measured electrical quantities. Nevertheless, when a non destructive measurement is required, the measurement of the electrical conductivity can become rather difficult on parts with complex geometry. To that end, with the help of the Finite Element Modeling approach (FEM), a strategy is developed to characterize the local electrical properties of parts with a non-trivial geometry. http://hdl.handle.net/10985/11754 Characterization of the local incremental permeability of a ferromagnetic plate based on a four needles technique ARBENZ, Laure; BENABOU, Abdelkader; CLENET, Stephane; FAVEROLLE, Pierre; MIPO, Jean-Claude The performances of electrical machines depend highly on the behavior of ferromagnetic materials. In some applications, these materials operate under DC polarization, i.e. when the magnetic field oscillates around a DC bias. In that condition, it is required to know the incremental permeability which characterizes the magnetic behavior of the material around the operating point. In this paper, a non-destructive approach, involving a combination of experiment and Finite Element (FE) technique, is presented in order to determine the incremental permeability. The proposed sensor is based on the four-needles method. With this sensor, Bowler et al. have proposed a method to determine the initial permeability of homogeneous metal plates based on an analytical model. Here we propose to use the same kind of sensor to determine the incremental permeability. The measurement process is analyzed using a FE model. It is shown that the analytical approach reaches its limits if the permeability of the plate and its thickness become too high. A combination between the measurements and a FE model is introduced to overcome this Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/11754 2016-01-01T00:00:00Z ARBENZ, Laure BENABOU, Abdelkader CLENET, Stephane FAVEROLLE, Pierre MIPO, Jean-Claude The performances of electrical machines depend highly on the behavior of ferromagnetic materials. In some applications, these materials operate under DC polarization, i.e. when the magnetic field oscillates around a DC bias. In that condition, it is required to know the incremental permeability which characterizes the magnetic behavior of the material around the operating point. In this paper, a non-destructive approach, involving a combination of experiment and Finite Element (FE) technique, is presented in order to determine the incremental permeability. The proposed sensor is based on the four-needles method. With this sensor, Bowler et al. have proposed a method to determine the initial permeability of homogeneous metal plates based on an analytical model. Here we propose to use the same kind of sensor to determine the incremental permeability. The measurement process is analyzed using a FE model. It is shown that the analytical approach reaches its limits if the permeability of the plate and its thickness become too high. A combination between the measurements and a FE model is introduced to overcome this http://hdl.handle.net/10985/8268 General Analytical Model of Magnet Average Eddy-Current Volume Losses for Comparison of Multi-phase PM Machines with Concentrated Winding ASLAN, Bassel; LEGRANGER, Jerome; SEMAIL, Eric this paper studies magnet eddy-current losses in permanent magnet (PM) machines with concentrated winding. First of all, space harmonics of magnetomotive force (MMF) and their influence on magnet losses in electrical machines are investigated. Secondly, analytical model of magnet volume losses is developed by studying the interaction between MMF harmonics wavelengths and magnet pole dimensions. Different cases of this interaction are exhibited according to the ratio between each harmonic wavelength and magnet pole width. Then various losses sub-models are deduced. Using this analytical model, magnet volume losses for many Slots/Poles combinations of 3, 5, and 7 phase machines with concentrated winding are compared. This comparison leads to classify combinations into different families depending on their magnet losses level. Finally, in order to verify the theoretical study, Finite Element models are built and simulation results are compared with analytical calculations Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8268 2014-01-01T00:00:00Z ASLAN, Bassel LEGRANGER, Jerome SEMAIL, Eric this paper studies magnet eddy-current losses in permanent magnet (PM) machines with concentrated winding. First of all, space harmonics of magnetomotive force (MMF) and their influence on magnet losses in electrical machines are investigated. Secondly, analytical model of magnet volume losses is developed by studying the interaction between MMF harmonics wavelengths and magnet pole dimensions. Different cases of this interaction are exhibited according to the ratio between each harmonic wavelength and magnet pole width. Then various losses sub-models are deduced. Using this analytical model, magnet volume losses for many Slots/Poles combinations of 3, 5, and 7 phase machines with concentrated winding are compared. This comparison leads to classify combinations into different families depending on their magnet losses level. Finally, in order to verify the theoretical study, Finite Element models are built and simulation results are compared with analytical calculations