The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

Francois Vallee - One of the best experts on this subject based on the ideXlab platform.

  • Comparative analysis of two zero-current switching isolated dc-dc converters for auxiliary railway supply
    2008 International Symposium on Power Electronics Electrical Drives Automation and Motion, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50 Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600 V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway power supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

  • Comparative study of soft-switched isolated dc-dc converters for auxiliary railway supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    —In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semi- conductor devices, operation in the whole range of load, etc.) is presented. Index

  • Comparative Study of Soft-Switched Isolated DC-DC Converters for Auxiliary Railway Supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated DC-DC converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated DC-DC converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

Olivier Deblecker - One of the best experts on this subject based on the ideXlab platform.

  • Comparative analysis of two zero-current switching isolated dc-dc converters for auxiliary railway supply
    2008 International Symposium on Power Electronics Electrical Drives Automation and Motion, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50 Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600 V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway power supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

  • Comparative study of soft-switched isolated dc-dc converters for auxiliary railway supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    —In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semi- conductor devices, operation in the whole range of load, etc.) is presented. Index

  • Comparative Study of Soft-Switched Isolated DC-DC Converters for Auxiliary Railway Supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated DC-DC converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated DC-DC converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

A. Moretti - One of the best experts on this subject based on the ideXlab platform.

  • Comparative analysis of two zero-current switching isolated dc-dc converters for auxiliary railway supply
    2008 International Symposium on Power Electronics Electrical Drives Automation and Motion, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50 Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600 V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway power supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

  • Comparative study of soft-switched isolated dc-dc converters for auxiliary railway supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    —In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated dc-dc converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated dc-dc converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semi- conductor devices, operation in the whole range of load, etc.) is presented. Index

  • Comparative Study of Soft-Switched Isolated DC-DC Converters for Auxiliary Railway Supply
    IEEE Transactions on Power Electronics, 2008
    Co-Authors: Olivier Deblecker, A. Moretti, Francois Vallee
    Abstract:

    In modern railways coaches, the Electrical Separation between the high voltage side and the auxiliary equipments on the consumer side is realized by means of heavy and bulky 50-Hz transformers. In order to reduce the weight and size of the devices, today new power supply systems are proposed that consist in soft-switched isolated DC-DC converters with a lightweight medium frequency transformer and diverse output modules supplied by a common 600-V dc intermediate circuit. This paper aims to investigate in detail two such solutions of isolated DC-DC converters for auxiliary railway supply where zero-current transitions are achieved for the primary inverter switches. A comparison based on several criteria (overall power rating, losses in power semiconductor devices, operation in the whole range of load, etc.) is presented.

F. Dimroth - One of the best experts on this subject based on the ideXlab platform.

  • Mesa Separation of GaInP Solar Cells by Picosecond Laser Ablation
    IEEE Journal of Photovoltaics, 2017
    Co-Authors: J. Weber, V. Klinger, A. Brand, S. Gutscher, A. Wekkeli, A. Mondon, E. Oliva, F. Dimroth
    Abstract:

    Laser ablation processes provide a potentially low cost and fast technology for microstructuring semiconductors, metals, or dielectrics. This paper deals with picosecond laser ablation (λ = 532 nm, τ ≈ 9 ps) of III-V semiconductors. In particular, the external threshold fluence of thermal ablation is determined for InP, GaAs, and GaP. Furthermore, the applicability of laser ablation to the Electrical Separation of III-V solar cells is discussed. In this context, current-voltage characteristics are presented comparing GaInP single-junction solar cells separated by picosecond laser ablation and wet-chemical mesa etching. The laser process leads to a significant drop in open-circuit voltage and fill factor which is explained by a more than three times larger (unpassivated) surface area.

  • Mesa Separation of GaInP Solar Cells by Picosecond Laser Ablation
    IEEE Journal of Photovoltaics, 2017
    Co-Authors: J. Weber, V. Klinger, A. Brand, S. Gutscher, A. Wekkeli, A. Mondon, E. Oliva, F. Dimroth
    Abstract:

    Laser ablation processes provide a potentially low cost and fast technology for microstructuring semiconductors, metals, or dielectrics. This paper deals with picosecond laser ablation ( $\lambda = 532\,{\text{nm}}$ , $\tau \approx 9\,{\rm{ps}}$ ) of III–V semiconductors. In particular, the external threshold fluence of thermal ablation is determined for InP, GaAs, and GaP. Furthermore, the applicability of laser ablation to the Electrical Separation of III–V solar cells is discussed. In this context, current–voltage characteristics are presented comparing GaInP single-junction solar cells separated by picosecond laser ablation and wet-chemical mesa etching. The laser process leads to a significant drop in open-circuit voltage and fill factor which is explained by a more than three times larger (unpassivated) surface area.

Hideaki Maeda - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication of 16-Main-Core RE123 Split Wire Using Inner Split Method
    IEEE Transactions on Applied Superconductivity, 2019
    Co-Authors: Yasuteru Mawatari, Toshihiro Kuzuya, Yusuke Amakai, Yoshinori Tayu, Naoki Momono, Shinji Hirai, Yoshinori Yanagisawa, Hideaki Maeda
    Abstract:

    For application to ultrahigh-field nuclear magnetic resonance spectroscopy (e.g., 30 T), we have started to develop a REBa2Cu3O $_{7-\delta}$ (RE123, RE: rare earth) multi-core coated conductor in which the ceramic layers (RE123 and buffer layers) are Electrically separated to create multiple filaments. This method is called Electrical Separation by inner splitting, and the wire is called a split wire. The multi-core structure is fabricated using Electrical Separation by a phase stress, which utilizes the difference in toughness between ceramics and metal, such as partial V-bending by stress along the longitudinal direction of the coated conductor using a commercially available single-core RE123 coated conductor. In addition, about ten narrow cores (width: 5–15 μm) can be formed by one bending. These cores are called subcores. The wire is composed of main cores and subcores. In this study, a 4-mm-wide multifilamentary RE123 split wire with 16 main cores and 150 subcores was fabricated and evaluated. The manufacturing method, microstructure, and critical current properties under an external magnetic field and tension are presented.

  • Fabrication of 16-Main-Core RE123 Split Wire Using Inner Split Method
    IEEE Transactions on Applied Superconductivity, 2019
    Co-Authors: Yasuteru Mawatari, Toshihiro Kuzuya, Yusuke Amakai, Yoshinori Tayu, Naoki Momono, Shinji Hirai, Yoshinori Yanagisawa, Hideaki Maeda
    Abstract:

    For application to ultrahigh-field nuclear magnetic resonance spectroscopy (e.g., 30 T), we have started to develop a REBa2Cu3O7-δ (RE123, RE: rare earth) multi-core coated conductor in which the ceramic layers (RE123 and buffer layers) are Electrically separated to create multiple filaments. This method is called Electrical Separation by inner splitting, and the wire is called a split wire. The multi-core structure is fabricated using Electrical Separation by a phase stress, which utilizes the difference in toughness between ceramics and metal, such as partial V-bending by stress along the longitudinal direction of the coated conductor using a commercially available single-core RE123 coated conductor. In addition, about ten narrow cores (width: 5-15 μm) can be formed by one bending. These cores are called subcores. The wire is composed of main cores and subcores. In this study, a 4-mm-wide multifilamentary RE123 split wire with 16 main cores and 150 subcores was fabricated and evaluated. The manufacturing method, microstructure, and critical current properties under an external magnetic field and tension are presented.