Nos publications scientifiques
CFD Investigation of Complex Phenomena in S-Shape Region of Reversible Pump-Turbine
Pumped Storage Plants (PSP) using reversible pump-turbines offer the possibility to store large amounts of energy with high efficiency and at reasonable cost. For reversible high head pump-turbines, the characteristic curves exhibit an S-shape in the turbine, turbine break and reverse pump quadrants. This S-shape leads to unstable behavior of the turbine when coupling to the grid (for small guide vane opening) or to surge transient phenomena in case of emergency shutdown (for large guide vane opening).
Leakage Current Measurements in Direct Current Gas Insulated Substations Equipment
Charge accumulation on solid insulator in Gas Insulated Substation (GIS) is one of the major issues under Direct Current (DC). A specific device has been developed in order to assess the origin of such charges within SF6, in a coaxial geometry.
DC-DC Converters for HVDC Grids: A Survey
The recent interest in renewable energies has encouraged the research on a new concept of electrical grid - the Supergrid based on HVDC meshed grids. To be implemented, this new system requires the development of new technologies. One key-enabling technology is the high power DC-DC converter, a topic that is increasingly gaining more attention from both academia and industry.
A Preliminary Loss Comparison of Solid-State Transformers in a Rail Application Employing Silicon Carbide (SiC) MOSFET Switches
The silicon carbide (SiC) power semiconductor and the medium frequency transformer (MFT) are two enabling technologies that are allowing the efficiencies and power densities of power electronic converters to be pushed beyond the limits of those that have previously been possible...
Barrier effect on Surface Breakdown of Epoxy Solid Dielectric in SF6 with Various Pressures
This paper is aimed at the experimental study of creeping discharges and flashover of cylindrical epoxy solid insulators with and without barrier.
Time constant evaluation of transient AC – DC field distribution
HVDC (High Voltage Direct Current) technology is particularly suitable for the transmission of high-power energy over long distances. However, some technical/technological problems have to be addressed/managed when passing from HVAC to HVDC due among others to the fact that the electric field distribution in gas insulated systems (GIS) operating under DC stress is very different from AC conditions.
Surface Flashover of Solid Insulator in Air
This paper is aimed at the propagation of discharges over a surface of insulator and the development of an analytical flashover model in air at atmospheric pressure. The experimental results show that the critical conditions of flashover are over the half of creeping distance.
Simulation methodology for DC GIS
Dimensionning of DC isulation is relatively complexe and need to take into account must more effects and parameters than in AC. This paper presents simulation methodology to applied for DC GIS and GIL.
Best Conference Paper Award, EPEC 2015
In the future, Medium Frequency Transformers (MFT with a frequency range 5 kHz to 100 kHz) will be major components in DC-DC converter applications, for both Medium Voltage Direct Current (MVDC) and High Voltage Direct Current (HVDC) networks. Importantly, the corresponding power losses should be accurately calculated in order to reach performance targets (very high efficiency).
Load transfer capabilities of GIS disconnectors for DC grids
The paper focuses on the role of disconnectors for load transfer duties in the operation of MTDC meshed grids. As there are no topology existing today and no standard, some switching duties are presented for which disconnectors could act instead of using circuit breaker. Based on an empirical model relying on tests performed in air, severity of the different switching duties are presented and first conclusions are proposed.
