Open AccessEffect of barrier thickness of Polytetrafluoroethylene on the Direct Current breakdown characteristics of liquid nitrogen
Author(s) -
Xiang Bin,
Gao Lei,
Zhang Jiahui,
Zhang Qi,
Liu Zhiyuan,
Geng Yingsan,
Wang Jianhua,
Tu Youping
Publication year - 2022
Publication title -
high voltage
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.732
H-Index - 20
ISSN - 2397-7264
DOI - 10.1049/hve2.12197
Subject(s) - liquid nitrogen , materials science , breakdown voltage , composite material , dielectric strength , polytetrafluoroethylene , current (fluid) , voltage , dielectric , direct current , fault current limiter , electrical engineering , optoelectronics , chemistry , organic chemistry , engineering , power (physics) , physics , electric power system , quantum mechanics
When high‐temperature superconducting (HTS) tapes in high voltage DC HTS devices are quenched, amounts of thermal bubbles are generated in liquid nitrogen (LN 2 ) that will reduce the insulation strength greatly. Especially when resistive‐type superconducting fault current limiters meet a short‐circuit fault, the insulation strength of the LN 2 decreased significantly due to the thermal bubbles and electrothermal pressure. Solid insulating barriers can improve the insulation strength of the LN 2 . The objective of this study is to obtain the effect of barrier thickness on the DC dielectric breakdown characteristics of LN 2 . Insulating barrier Polytetrafluoroethylene with three different thicknesses were tested. Three types of electrodes such as rod‐plane, needle‐plane, and plane‐plane were applied. The results showed that the barriers can increase the negative and positive breakdown voltage both with and without thermal bubbles in a slightly non‐uniform field (SNF) and non‐uniform field (NF). For the SNF, the DC breakdown voltage is higher when the barrier is thinner. The effect of the barrier thickness in the NF is lower than that in the SNF field. For the NF, the positive breakdown voltage is higher when the barrier is thicker.