27 August 2017 to 1 September 2017
RAI Congress Center, Amsterdam, The Netherlands
Europe/Amsterdam timezone

Determination of Threshold Electric Field for PPLP Specimen in Liquid Nitrogen Based on the Measurement of Electrical Conductivity

29 Aug 2017, 13:15
1h 45m
Posters Area

Posters Area

Poster Presentation of 1h45m H3 - Other Associated Technologies Tue-Af-Po2.12


Mr Ik-Soo Kwon (Department of Electronic System Engineering)


AC electric field distribution in composite insulation materials is mainly determined by their permittivity. However, DC electric field distribution highly depends on the electrical conductivity of the insulating materials, and this electrical conductivity exponentially increases with externally applied electric field in cryogenic environment. Therefore, we should not only obtain the accurate electrical conductivity according to externally applied electric field but also necessary to find out the threshold electric field of each insulation material for the desirable insulation design of dc power apparatuses. Accurate determination of the threshold electric field at which charge injection from the electrodes increases is the important matter for the reliable electric field analysis. Due to the presence of space charge in the insulation material, it could lead to the electric field enhancement, resulting in degradation and early failures of the insulation material. Therefore, in this paper, we tried to measure the electrical conductivity of the Polypropylene Laminated Paper (PPLP) specimen in liquid nitrogen (LN2) and find out the threshold electric field. PPLP was widely known as insulating layer for dc High Temperature Superconducting (HTS) Power cable and the examination of the electric field characteristics of PPLP is very important for the reliable insulation design of dc HTS power cable. For the verification of the experimental results, the simulation works were performed using COMSOL Multiphysics in HTS cable model for the comparison of the electric field distribution depending on whether the threshold electric field were considered or not. Consequently, it was possible to deduce the threshold electric field for PPLP was around 10.34 kV/mm, and this value could vary the dc electric field distribution of HTS cable.

Submitters Country Republic of Korea

Primary author

Prof. Bang-Wook Lee (Division of Electrical Engineering)


Mr Ik-Soo Kwon (Department of Electronic System Engineering) Mr Kuniaki Sakamoto (Department of Electronic System Engineering) Jin-Yong Na (Department of Electronic System Engineering) Mr Jae-Hong Koo (Department of Electronic System Engineering)

Presentation Materials