This paper deals with the current decay characteristics of a high-T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> superconducting (HTS) coil operated in persistent mode (PCM) under alternating magnetic field. In synchronous machine applications, such as linear motor (LSM), coils are designed to operate PCM obtain steady-magnetic field DC transport current. operates on direct current, but it can be exposed due armature winding. When...

A study on the dielectric characteristics of various cryogenic materials should be conducted to design an electrically reliable high-voltage superconducting apparatus. Especially, gaseous and solid insulation are important for designing current lead parts, those indispensable coil parts. subcooled liquid nitrogen (LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) cooling system is most promising, with respect insulation, thermal...

In the Republic of Korea, it is widely thought that subcooled liquid nitrogen cooling system most promising method to develop a high-voltage superconducting apparatus. This involves injecting gaseous insulation medium, such as He, Ne, or N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , into apparatus control pressure [1]. Therefore, study on dielectric characteristics and solid materials must be conducted design current lead parts for...

Full transposition of superconducting wires within a conductor may not be requirement for high temperature superconductor (HTS) magnet fusion applications. Already, conduction-cooled 20 T model coil built with non-transposed HTS stacks has been demonstrated by Commonwealth Fusion Systems (CFS). Here, we discuss 3 possible stacked cryogen-cooled concepts toroidal field (TF) The first one is somewhat like LTS conductors, the second, are capped copper stabilizer, last one, only without copper....

To achieve nuclear fusion energy generation, continuous confinement of high-current and long-pulse plasma is necessary. KSTAR has been conducting experiments to this goal. In order maintain a steady state current, the superconducting magnets tokamak should also be operated stably, with heat controlled minimum. However, slight increase in outlet temperature PF (poloidal field) magnet current ripple were observed, particularly when ramp rate 0.5 kA/s or less. range, evaluated AC loss showed...

A significant number of recent studies have explored the impact many kinds winding insulation conditions on high-temperature superconducting (HTS) coils for application electric devices. HTS coil co-wound with turn-to-turn inserted materials could be an appropriate alternative to no-insulation because poor charge-discharge delay and unexpected quench behavior coil. In addition, has good thermal stability mechanical integrity, making it useful applications such as magnetic energy storage...

Three kinds of solid insulation materials, such as glass-fiber-reinforced plastic (GFRP), Bakelite, and MC Nylon, are often used in high-voltage superconducting apparatuses formers barriers to improve dielectric characteristics. GFRP, Nylon considered promising candidates cryogenic materials for developing a apparatus due their excellent characteristics robust mechanical strength under conditions. The surface roughness could differently vary depending on the machining processes. These...

Several types of solid materials are used in the development high voltage superconducting magnet systems as former and insulation barrier. The cryogenic applications require excellent dielectric characteristics well robust mechanical characteristics. In this study, experiments for three materials, including glass fiber reinforced plastic (GFRP), epoxy (Stycast 2850FTJ), Bakelite liquid nitrogen (LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

As electric power systems become more complicated, the fault current experiences frequent changes. To solve this problem, we suggest a novel hybrid-type superconducting limiter (SFCL). Some issues accompany application of resistive-type SFCLs to systems, including initial installation price, operation and maintenance costs, high-current problems. overcome these problems, hybrid have been developed in some institutions. This paper presents experimental tests SFCL composed resistive coil, two...

The accidents caused by dielectric instability have been increasing in power grid. It is important to enhance the reliability of a high voltage apparatus reduce damage from electrical hazards. To develop an electrically reliable apparatus, experimental study on breakdown field strength indispensable, as well theoretical approach. In this paper, lightning impulse characteristics considering utilization factors are studied for establishment insulation design criteria apparatus. represented...

Flux diverters made of ferromagnetic materials can be used in high-temperature superconducting (HTS) magnets to change the magnetic field distribution and increase critical current magnet. In this paper, notch-shaped flux diverter increases HTS magnet by detouring more effectively than flat surface-shaped (simple) diverter. Numerical analyses are carried out calculate using simple-shaped diverters. Then, experiments conducted verify results numerical analyses. As a result, coil with shows...

The TF coil structures are the main structural components in magnet system, and consist of cases, inter-coil structures, gravity support interface structures. enclose coils to protect CICC from mechanical, electrical thermal loads, 7 pairs PF coils. behavior has been monitored during cool-down plasma operation for over 10 years. High stress large displacement regions investigated through review structure design. measured behaviors compared with estimated design analyses. discrepancy between...

Recently, production technique and property of the High-Temperature Superconductor (HTS) tape have been improved. Thus, study on applying an HTS magnet to high magnetic field application is rapidly increased. A Nuclear Magnetic Resonance (NMR) spectrometer requires magnitude homogeneous central field. However, has fabrication errors because shape manufactured by winding bobbin. The are error, bobbin diameter spacer thickness error so on. occurs when departed from arranged position occur...

The electrical insulation design for a superconducting system is important when developing high-voltage apparatus as substitute conventional one. In this paper, the degradation characteristics of 2G high temperature (HTS) wires, with respect to breakdown tests, were studied. It was found that materials in HTS wires can be damaged breakdown, and structure results Ic index number. As result, it affected by stabilizer material applied voltage. Thus, hardness conductivity considered parameters...

The environmental pollution caused by green-house gases such as CO₂ and SF6 has been becoming the main issue of industrial society. Many developed countries are making efforts to minimize amount emission come from operation high voltage electrical apparatuses. As a part these efforts, 180 signed Kyoto Protocol in 1997 cut back on their gas emissions. Nowadays, study development dry air insulated switchgear (DAIS) which is known an eco-friendly apparatus progress. A DAIS advantageous for...

Superconducting cables are one of the most promising applications among several high voltage superconducting power apparatuses owing to its low energy loss and capacities. system consists four parts: termination, joint box, core, cooling system. The core is responsible for transport, insulated with polypropylene laminated paper (PPLP) ensure a dielectric strength in presence liquid nitrogen (LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Fully equipped with superconducting magnets, KSTAR has successfully conducted experimental campaigns for 15 years since 2008. The operating environment of become challenging due to long pulse durations, high temperatures, and large plasma currents. 16 TF coils 7 pairs PF experience substantial electromagnetic forces during discharge, given the current magnetic field, coil structure bears these loads. Strain gauges were installed monitor stresses in structures cool-down operation. This study...

A Quench Detection System (QDS) will be installed for the ITER superconducting coils and feeder system. The objective of QDS is to detect a quench in device protect devices. This paper aims provide functional specification qualification method QDS. In baseline I/O, protection magnet investment defined carried out through electrical signal processing. Therefore, primary function voltage drop across unrecoverable normal zone system send trigger Central Interlock activate circuit. Due their...

Study of the dielectric characteristics on gaseous insulation media is important for designing and developing current leads superconducting machines with a sub-cooled cooling method. In case using N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> method, medium, such as He, Ne, SF xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> , CF xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> or should be injected to control pressure enhance...

Smart fault current controller (SFCC) proposed in our previous work consists of a power converter, high temperature superconducting (HTS) DC reactor, thyristors, and control unit [1]. SFCC can limit the by adjusting firing angles thyristors when occurs. has complex structure because HTS reactor generates loss under AC. To use AC, rectifier that four is needed it increases internal resistance SFCC. For this reason, authors propose hybrid type limiter (SFCL). The SFCL paper non-inductive coil...

The Quench Detection System (QDS) for the Toroidal Field (TF) coils and Poloidal (PF) made of Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn or NbTi cable-in-conduit conductors is using Wheatstone bridges to compensate induced voltages, which are generated by electrical currents superconducting a plasma, on quench detection circuits Korea Superconducting Tokamak Advanced Research (KSTAR) device. On other hand, KSTAR device...