This paper presents a procedure for designing a power converter to produce power pulses in the conductive parts of a cable (core or shield) for non-invasive space charge measurements with a thermal wave.
An experimental study of breakdown and pre-breakdown phenomena in liquid nitrogen (LN2) is performed in this paper, in order to provide useful knowledge for the design of high voltage superconducting systems.
An experimental study of breakdown and pre-breakdown phenomena in liquid nitrogen (LN2) is performed in this paper, in order to provide useful knowledge for the design of high voltage superconducting systems.
De par sa facilité d’utilisation et sa capacité à isoler la permittivité complexe représentant les pertes dans un matériau tout en faisant un balayage fréquentiel, la spectroscopie diélectrique semble être une méthode de choix pour obtenir la valeur de conductivité ohmique d’un matériau. Cette méthode pourrait permettre de s’affranchir des temps conséquents de stabilisation généralement associés aux mesures de conductivité issues de courbes courant-tension effectuées suivant la norme IEC 62631-3. Par l’intermédiaire d’une comparaison entre ces 2 méthodes, les auteurs vont revenir sur les limites de chacune d’entre elle.
The present paper aims at describing the measurement methods applied to mock-up cables in order to evaluate their dielectrics. The focus is on leakage current and temperature measurements together with the processing based upon them to assist in the selection of the more appropriate material.
The present paper aims at describing the measurement methods applied to mock-up cables in order to evaluate their dielectrics. The focus is on leakage current and temperature measurements together with the processing based upon them to assist in the selection of the more appropriate material.
Different surge arrester configurations are studied for a modular multilevel converter (MMC) in a symmetrical monopole configuration. Each configuration is analyzed under fault conditions including DC side faults and faults inside the converter station. The configurations considered are compared in terms of overvoltages, current levels and energy dissipation.
This article presents the topology for non-isolated MMC-based DC-DC converter. The initial design study illustrates that such DC/DC converter will have overall semiconductor count comparable to a MMC AC-DC (used with HVDC transmission) converter of similar rating. A full controller schematic is presented and operating principles are discussed.
This paper proposes an in-depth analysis from the control point of view of dynamic models of a Modular Multilevel Converter (MMC) for high-voltage direct current (HVDC) application.
In able to fully integrate renewable energies and to stop to use fossil energy and nuclear power, there is a need to evolve the current electric grid in a new one called the supergrid. This new grid will be based on a mix of High Voltage AlternativeCurent (HVAC) and High voltage Direct Current (HVDC) junctions highly meshed with Gas Insulation Substation (GIS) as nodes. While HVAC GIS technologies are well mastered, HVDC ones are still at the beginning. One weakness of the equipment being dielectric insulators, industries may have to conceive new dielectric formulations or improved ones. This paper presents a list of properties and values to target for future dielectrics formulation. At the end, it highlights as well, the importance of health and environnement and how their consideration have to be at the same level of attention than the final properties of the dielectrics.
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