Mechanism of partial discharges in free helium bubbles in transformer oil

Autor:	D. I. Karpov, Sergey M. Korobeynikov, M. B. Meredova, A. G. Ovsyannikov, A. V. Ridel
Rok vydání:	2019
Předmět:	010302 applied physics Materials science Photon Transformer oil chemistry.chemical_element Electron 01 natural sciences Glass microsphere chemistry Electric field 0103 physical sciences Electrical and Electronic Engineering Atomic physics Event (particle physics) Helium Voltage
Zdroj:	IEEE Transactions on Dielectrics and Electrical Insulation. 26:1605-1611
ISSN:	1558-4135 1070-9878
DOI:	10.1109/tdei.2019.008199
Popis:	Partial discharges (PD) in floating bubbles and in microspheres made from thin glass walls in transformer oil were studied experimentally and theoretically. In a test cell, the PD occurrence was a very rare event. Sometimes PD in bubbles occurred after exposure for more than 10 hours at a voltage that corresponds to a value three times the voltage in accordance with Paschen's law. In the case of a glass microsphere, PD takes place at a voltage according to Paschen's law after several hours but afterwards PD occurs more frequently. The reason for this is in the starting electrons which initiate the first avalanche. It is shown with 100 keV X-rays that PD occurs in all bubbles and its inception voltage corresponds to Paschen's law. Theoretical analysis shows that, at the conditions of PD occurrence in helium bubbles, breakdown fits the streamer mechanism. Registrations of electrical and optical signals of PD were performed to estimate apparent and true charges and the number of radiated photons. As a result of the evaluation, the number of electrons is approximately equal to the number of photons.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::290aef71f9c3c84fe2e6845d72c3762a https://doi.org/10.1109/tdei.2019.008199 Zobrazit plný text záznamu