Experimental Design and Test of 100 kV Extra High Voltage Prototype Bushing With ${\rm CF}_{4}$ as Insulation Gas for Superconducting Equipment

Abstract

One of the critical matters yet to be solved for commercial applications of extra high voltage superconducting devices is the optimum design and development of high voltage cryogenic bushings which could withstand both severe insulation requirements and a steep temperature gradient due to the cryogenic environment. Neither conventional extra high voltage bushings insulated by gas nor composite materials are directly applicable to cryogenic bushings due to an extremely low temperature environment. In order to obtain suitable dielectric performance of bushings in the cryogenic environment, we focused on an alternative insulation gas instead of such as , which shows excellent dielectric performance under extremely low temperatures, and also on the optimum design of cryogenic bushings, which have a longer creepage distance compared to conventional bushings. In this paper, design factors of cryogenic bushings were discussed, and test results of 60 and 100 kV extra high voltage prototype bushings were discussed in detail. Consequently, it was possible to obtain satisfactory results to verify the insulation level of newly designed extra high voltage cryogenic prototype bushings for superconducting electric power applications.

An Investigation on Surface Flashover Characteristics of FRP in Several Insulation Gases for the Spacer of Cryogenic Bushing

“…2 shows the manufactured FRP spacer which is installed in the middle part of cryogenic bushing. 3 and b=1016 mbar which are almost corresponded to the standard reference atmosphere (t 0 =20°C, h 0 =11 g/m 3 and b 0 =1013 mbar) in IEC 60060-1. And an experimental test cell and a cylindrical FRP specimen were shown in the right side of Fig.…”

“…However, the cryogenic bushings have not been fully developed due to severe insulation requirements. Cryogenic bushings should be safely able to supply the current and overcome high voltage cryogenic issues under intense thermal variation from room temperature to extremely low temperature [3].…”

A Comprehensive Review of Operation and Control, Maintenance and Lifespan Management, Grid Planning and Design, and Metering in Smart Grids

“…According to high voltage or extra high voltage, Hwang et al [292] apply cryogenics to the bushes of the lines, and validate two prototypes of 60 and 100 kV.…”

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

“…A 60 kV FRP condenser cone cryogenic bushing was fabricated using the design criterion of gas type cryogenic bushing based on our previous work [6]. The insulation thickness and creepage distance of FRP were chosen by the dielectric performance of FRP in liquid nitrogen.…”