English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Surface flashover fault is one of the most challenge issues in oil-cellulose insulation pressboard system used in power transformer. In this study, a comparative study of the AC surface flashover properties of the novel 3-element mixed oil-cellulose insulation pressboard (3EMO-IP) and mineral oil-cellulose insulation pressboard (MO-IP) was performed under needle-plate and finger-finger electrode, respectively, measurement including dielectric property, surface flashover voltage, damage of cellulose pressboard surface and the gas generation behaviors after multiple surface flashover. Results show that the cellulose insulation pressboard immersed in the novel 3-element mixed insulation oil (3EMO) has higher relative permittivity and dielectric loss factor at 50 Hz, and also has slightly lower surface resistivity. The AC surface flashover voltage of the 3EMO-IP is higher than that of MO-IP under needle-plate and finger-finger electrode (electrode distance 5 mm, 10 mm, 15 mm and 20 mm). Compared to MO-IP, the lower electric field intensity at the oil-pressboard interface, as well as more difficult for surface charge accumulation of 3EMO-IP and the higher breakdown voltage of 3EMO lead to the higher AC surface flashover voltage of 3EMO-IP. Moreover, the carbonization of fibers in 3EMO-IP is slightly less. After multiple surface flashover, C2H2 and total hydrocarbon gases are the main differences between 3EMO-IP and MO-IP, which is more marked with the increase of flashover times. This study offers a reference for improving the surface flashover property of oil-pressboard insulation system by using 3EMO.

AC Surface Flashover and Gas Generation Difference of the Cellulose Insulation Pressboard Immersed in Novel 3-Element Mixed Oil and Mineral Oil