Research on the Insulation Design of a 154 kV Class HTS Power Cable and Termination

Abstract

A 154 kV class high-temperature superconducting (HTS) power cable system is developing in Korea. For insulation design of this cable, the grading method of insulating paper is proposed. The electrical insulation material has been used two kind of laminated polypropylene paper (LPP) that has different thickness. The use of graded insulation gives improved mechanical bending properties of the cable. Also, within a HTS cable technology the terminations are important components. A HTS cable termination is energized with the line-to-ground voltage between the coaxial center and outer surrounding conductors, in the axial direction there is a temperature difference from ambient to about 77 K. For insulation design of this termination, the insulation material of the termination body used glass fiber reinforced plastic (GFRP) and the capacitance-graded method is proposed. Therefore, in order to insulating design of a 154 kV class HTS power cable and termination, this paper will report on the experimental investigations in impulse breakdown and surface flashover characteristics of the insulation materials. Based on these experimental data, the electrical insulation design of a 154 kV class HTS power cable and termination were calculated.

A Study on the DC and Impulse Breakdown Performances of PPLP Insulation in Liquid Nitrogen for DC Applications

“…To examine the effect of space charge on breakdown voltage, therefore, a test which differs from the conventional method of AC applied voltage [6] is performed.…”

“…We have been studied on the development of HTS AC machines and electrical insulation design as a part of the 21st century frontier project [6,7]. However, it has been almost impossible to study the HTS DC machines.…”

Breakdown characteristics of glass fibre reinforced plastic for termination of high temperature superconducting cable

“…Thus, GFRP has been selected as an insulator for HTS termination in this study. Surface discharges of GFRP in various physical states of nitrogen for an HTS termination were presented in previous studies [7,8], where there is, however, still a lack of data on puncture breakdown of GFRP, breakdown strength-time relationship and breakdown characteristics of GFRP for insulation design of the HTS termination. Therefore, an investigation of the influence of different states of nitrogen on breakdown characteristics of GFRP for providing a better insight in this field of study is essential.…”

Electrical insulation design and evaluation of 60kV prototype condenser cone bushing for the superconducting equipment

“…In addition, normal epoxy insulation for cryogenic bushing is not viable due to the crack occurrence in the cryogenic environment caused by thermal contraction and thermal expansion [1,2]. Therefore, in our study, fiber reinforced plastic (FRP) was selected for the insulation material of cryogenic bushing.…”