This paper presents a simulation methodology that can be used to evaluate the electric stresses in GIS/cable termination under different operating conditions including polarity reversal and superimposed impulses.
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.
Comparaison de mesures de conductivité obtenues par spectroscopie diélectrique et mesure de courant sous tension continue sur une résine époxy
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.
PhD Loriane DESMARS “Study of electrical and thermal properties of epoxy-anhydride composite materials for high voltage insulation”
The work presented in this manuscript has been motivated by the necessity to develop more efficient electrical insulating materials compared to commercially available ones. An epoxy-anhydride matrix filled with micron sized alumina, often used to produce GIS solid insulators, has been used as a reference for this study.
The rational insulation design of a resistive superconducting fault current limiter (r-SCFCL) requires data gathered from experimental setups representative of the final apparatus. Therefore, an experimental study was performed to characterize the electrical breakdown (BD) of liquid nitrogen (LN2) in the peculiar conditions of a quenching superconducting device.
Arc appearance and cathode spot distribution in a long gap high-current vacuum arc controlled by an external axial magnetic field
An experimental study of a high-current vacuum arc (VA) generated between two static CuCr25 contacts spaced 20 or 30 mm apart was conducted to characterize the arc appearance and the cathode spot (CS) distribution.
In accordance with their interesting properties, ionic liquids (ILs) have attracted in the recent years a great interest in the material field. Recently, few authors have demonstrated the reactivity of ionic liquids towards epoxy in order to form new epoxy-based networks...
PhD Etienne OUSS “Characterization of Partial Discharges and Defect Identification in High-Voltage Direct Current GIS”
This thesis aimed to characterize partial discharges in DC gas-insulated substations, and to develop an automatic defect identification tool. The first step of this work was the development of a partial discharge measuring bench. The complete study has been performed in a GIS section, so that the results can be directly applied to industrial equipment.
Models of AC and DC cable systems for technical and economic evaluation of offshore wind farm connection
Accurate cable modeling is a recurrent issue for electric architecture evaluation and design, especially in specific contexts, like offshore wind farms. This paper proposes optimal analytical cable models for the technical and economic assessment of offshore wind generation systems.
High voltage direct current (HVDC) technologies are currently emerging to develop new energy transmission networks able to integrate renewable energy sources with remote locations from consumers. Gas Insulated Substations (GIS) have been widely used in alternating current (AC) transmission due to their low footprint and high reliability.