P. Vinson

Bio: P. Vinson is an academic researcher. The author has contributed to research in topics: Breakdown voltage & Dielectric. The author has an hindex of 2, co-authored 2 publications receiving 166 citations.

Fluoronitriles/CO2 gas mixture as promising substitute to SF6 for insulation in high voltage applications

Abstract: This paper is aimed at the breakdown characteristics of Fluoronitriles – CO2 gas mixtures in different experimental conditions; these mixtures constitute promising substitutes to SF6 gas in high voltage applications especially gas insulating switchgear (GIS). Fluoronitriles chemical gas compound based on 3M NOVEC 4710 have a high dielectric strength, more than 2 times that of SF6 and a low Global Warming Potential (GWP). Mixed with CO2 as gas carrier, the obtained mixtures offer interesting dielectric properties and the possibility to be used for low temperature applications. The experiments are conducted with different electrodes geometries namely plane-to-plane, sphere-to-sphere, sphere-to-plane and rod-to-plane (i.e. in homogeneous, quasi-homogeneous and inhomogeneous electric field distribution) and different field utilization factors, under AC and lightning impulse voltages. The same experiments are reproduced for pure SF6 for the comparison. The comparison of breakdown voltages results of mixtures with different concentrations of Fluoronitriles in CO2 in sphere-to-sphere electrodes arrangement shows that the 3.7 % Fluoronitriles / 96.3% CO2 mixture constitutes a good compromise and an appropriate gas mixture for high voltage apparatus insulation in point of view of pressure and low ambient temperature application (-30°C).

Effective ionization coefficients and limiting field strength of fluoronitriles-CO2 mixtures

Abstract: The density normalized effective ionization coefficients and critical breakdown electric field of the Heptafluoro-iso-butyronitrile (Fluoronitriles), and Fluoronitriles-CO2 mixture are investigated using the steady state Townsend (SST) experimental setup, over a range of the density normalized critical electric field (E/N) from 200–1066 Td (E is the electric field and N the gas density). Breakdown voltage measurements are also performed to plot the Paschen curves for small product values (N×d) (d being the electrode gap), to identify the Paschen minimum, and to validate the density normalized critical electric field (E/N)0 when α=η (α and η are the ionization and attachment coefficients, respectively). The influence of electrode surface roughness is also analyzed.

Recent Advances in the Quest for a New Insulation Gas with a Low Impact on the Environment to Replace Sulfur Hexafluoride (SF6) Gas in High-Voltage Power Network Applications

Abstract: The growing environmental challenge of electrical energy systems has prompted a substantial increase in renewable energy generation. Such generation systems allow for significant reduction of CO2 emissions compared with a traditional fossil fuel plant. Furthermore, several improvements in power systems network configuration and operation combined with new technologies have enabled reduction of losses and energy demand, thus contributing to reduction of CO2 emissions. Another environmental threat identified in electrical networks is the leaking of insulating sulfur hexafluoride (SF6) gas used in electrical gas insulated substations (GIS) and equipment. Because of its Global Warming Potential (GWP) of nearly 24,000 and its long life in the atmosphere (over 3000 years), SF6 gas was recognized as a greenhouse gas at the 1997 COP3; since then its use and emissions in the atmosphere have been regulated by international treaties. It is expected that as soon as an alternative insulating gas is found, SF6 use in high-voltage (HV) equipment will be banned. This paper presents an overview of the key research advances made in recent years in the quest to find eco-friendly gases to replace SF6. The review reports the main properties of candidate gases that are being investigated; in particular, natural gases (dry air, N2 or CO2) and polyfluorinated gases especially Trifluoroiodomethane (CF3I), Perfluorinated Ketones, Octafluorotetra-hydrofuran, Hydrofluoroolefin (HFOs), and Fluoronitriles are presented and their strengths and weaknesses are discussed with an emphasis on their dielectric properties (especially their dielectric strength), GWP, and boiling point with respect to the minimum operating temperature for HV power network applications.

Effective ionization coefficients and limiting field strength of fluoronitriles-CO2 mixtures

Abstract: The density normalized effective ionization coefficients and critical breakdown electric field of the Heptafluoro-iso-butyronitrile (Fluoronitriles), and Fluoronitriles-CO2 mixture are investigated using the steady state Townsend (SST) experimental setup, over a range of the density normalized critical electric field (E/N) from 200–1066 Td (E is the electric field and N the gas density). Breakdown voltage measurements are also performed to plot the Paschen curves for small product values (N×d) (d being the electrode gap), to identify the Paschen minimum, and to validate the density normalized critical electric field (E/N)0 when α=η (α and η are the ionization and attachment coefficients, respectively). The influence of electrode surface roughness is also analyzed.

Electrical insulation properties of the perfluoronitrile C4F7N

Abstract: The electrical insulation properties of pure C4F7N and of C4F7N/N2 and C4F7N/CO2 mixtures are investigated in a pulsed Townsend setup. The electron rate and transport coefficients and the density-reduced critical electric field of these mixtures are obtained, and a synergy effect is observed in C4F7N/N2 and C4F7N/CO2 mixtures. The total electron attachment cross section of C4F7N is estimated based on the attachment rate to C4F7N in diluted C4F7N/N2, C4F7N/CO2 and C4F7N/O2/CO2 mixtures. Measurements in pure C4F7N at pressures of a few hundred pascal show that ion kinetics play a major role in C4F7N discharges and that further modelling is required to assess the electric strength of C4F7N at high pressures.