This study analyzes the current bypass mechanism of a metal stitching smart insulation (SI) coil rolled by coating vanadium oxide (V2O3) on a metal stitching wire prepared by generating micro-holes into a second generation (2G) high-temperature superconducting (HTS) wire using a laser and by filling the micro-holes with metal solder material. Results showed that the metal stitching wire with...
V2O3 has been studied as a smart insulation material for 2G high-temperature superconducting (HTS) coils owing to its remarkable metal-to-insulator transition (MIT) upon heating or cooling via a critical temperature (Tc) of ~160 K. The smart insulated (SI) coil regulates its function according to the MIT properties of V2O3. At temperatures below Tc, V2O3 acts as an insulator, whereas it...
The High Temperature Superconducting (HTS) magnet system is immersed in a sub-cooled liquid nitrogen (LN2) and continuously refrigerated by a cryogenic cooling system. Especially, in case of the side-wall cooling type, the HTS magnet system is located well below the level of LN2 for thermal and electrical safety and the cryogenic gaseous nitrogen (CGN2) is filled above LN2. However, the method...
Abstract: The YBCO racetrack pancake coils were wound by dry wing followed by impregnation. Various materials such as epoxy resin, paraffin, grease and so on with and without fillers were measured to impregnate coils. The superconducting characteristics of the coils after above different materials of impregnation were tested. Due to the anisotropic of the racetrack shaped coils, the...
The weight loss of the organic composite materials and their matrix resins have been measured in vacuum. These are intended for use as insulating materials of fusion superconducting magnets or as structural materials used in aerospace application. Since in these applications they are used under the radiation environments, the degradation of mechanical strength will be measured together with...
This study analyzes the output characteristics of a 100-turn non-rotational-type metal insulation (MI) coil and a no-insulation (NI) coil installed inside a 1-MW armature with external fluctuating magnetic fields. Experiments were conducted to investigate the change of state and output performance of the superconducting coils based on the fluctuating magnetic field prior to the development of...
The performance of accelerator magnets is strongly relying on the dielectric strength given by the electrical and mechanical robustness of the insulation system. This is in particular relevant for the current development of high field superconducting Nb3Sn magnets with their insulation system made from fibre reinforced resin. During the assembly and operation, this insulation system is exposed...
The strain sensitivity of Nb3Sn is considered one of the main challenges that has to be solved to use the full potential of this conductor in particle accelerator magnets application. In these applications, significant forces are applied to the superconducting coils both during the assembly and cooldown to cryogenic temperatures, and then during powering. The composite coil reacts...
Since superconducting technology has advantages of high efficiency, large capacity, and eco-friendliness, HVDC superconducting power devices such as superconducting cable, transformers, fault current limiters, and magnetic energy storage are being extensively studied. The creepage distance of solid insulator is very important for the reliable and economical insulation design of the HVDC...
High-temperature superconducting (HTS) cables are rapidly developed for their increased transmission capacity and reduced power transmission losses, and PPLP with excellent low-temperature dielectric and mechanical characteristics is used as insulation materials for HTS AC cables. However, unlike AC, since the direction of the electric field does not change in the DC environment, the space...
A variable resistance thin dielectric insulation coating for REBCO tape HTS coils has been developed. This new type of insulation system switches between fully insulating and conducting, after an increase in inter turn voltage. Non-Insulated (NI), fully soldered, HTS coils have proven to be very reliable; NI coils are achieving high magnetic fields above 25 Tesla and are almost impossible to...
