Controlling the lifetime of insulating materials is required to insure reliability of insulation systems for Medium Voltage (MV) and High Voltage (HV) cables. The aging behavior of Low Density (LDPE) and Cross-Linked Polyethylene (XLPE) under MV-AC thermo-electric stress is studied in the sphereplane geometry in air to identify degradation mechanis...
We investigate the dynamics of negative surface discharges in air through numerical simulations with a 2D fluid model. A geometry consisting of a flat dielectric embedded between parallel-plate electrodes is used. Compared to negative streamers in bulk gas, negative surface streamers are observed to have a higher electron density, a higher electric...
The present paper reports on the evidencing of the capacitive effects on the characteristic parameters of the surface discharges propagating over different types of insulators immersed in gases or dielectric liquids, in a point-plane electrode arrangement submitted to different types of voltage waveforms namely AC, DC and lightning impulse voltages...
The objective of this paper is to investigate the influence of environmental conditions on a nanosecond pulsed dielectric barrier discharge (NP-DBD). A test chamber where pressure and temperature can be changed to match with realistic altitude conditions has been used. Electrical and optical characterizations of the NP-DBD are proposed for pressure...
The ECP (end winding corona protection) of the armature coils of a synchronous generator is designed and modeled. The paper focuses on the distribution of voltage and temperature along this protection that is both measured and simulated. The results are compared. The aim of the work is to verify the suggested mathematical model which would help to ...
This study is aimed at the characterisation of surface discharges propagating over different solid materials namely glass, bakelite and epoxy resin immersed in three gases and their mixtures (namely SF6, N2 and CO2, SF6/N2 and SF6/CO2) under AC voltage (50 Hz) in a point-plane electrode system. It is shown that the stopping length of discharges (Lf...
During the last 50 years electricity demand has significantly increased. Large amounts of electricity are transported from the generation to the consumption sites. Overhead lines or underground cables are used to transport the required energy. High voltage levels are used to reduce the transmission losses. Power transformers are responsible for lin...
Two kinds of floating electrode, floating dielectric barrier covered electrode (FDBCE) and floating pin electrode (FPE), which can enhance the performance of plasma jet are reported. The intense discharge between the floating electrode and power electrode decreased the voltage to trigger the plasma jet substantially. The transition of plasma bullet...
il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION
Import 11/07/2012 / Cílem této bakalářské práce je zpracovat informace týkající se částečných výbojů. Jejich charakteristické vlastnosti, druhy a typy. Popsat jaké jsou jejich projevy, vlivy a působení na okolí. Jednou z důležitých částí této práce je část týkající se rušení, neboť v dnešní době využívající velkého počtu elektroniky se jedná o neza...
