This study examined the electrical properties of Ti/MnO2/Pt devices with stable and reproducible bipolar resistive switching behavior. The dependency memory behavior on cell area operating temperature suggest that conducting mechanism in low resistance states is due to locally filaments formed. X-ray photoelectron spectroscopy showed nonlattice oxygen ions form at MnO2 surface. system involves generation recovery vacancies ions.

This paper reports a study on BSCCO and ReBCO HTS (high temperature superconducting) test coils, layer-wound double-pancake, with without turn-to-turn insulation. Over current tests were performed in bath of liquid nitrogen to compare stabilities the coils at 77 K. Saturation magnetic fields from NI (no insulation) both ReBCO, was observed owing bypassing through contacts local quenches operating currents higher than their critical currents. In global occurred coil quench recoveries during...

Recently, studies of partially insulated, high-temperature superconducting (HTS) coils have shown application in the design and construction compact, stable self-protecting HTS coils. This article presents electrical characteristics based on turn-to-turn inserted materials conditions. Three co-wound pancake were fabricated tested. Each coil was with Kapton, stainless steel copper tape at every fourth turn winding. Tested tape, without insulation control group. Charge–discharge,...

This paper presents a study to determine the optimal resistive value of superconducting fault-current limiter (SFCL) for enhancing transient stability power system more effectively. A type SFCL, which provides quick protection, is modeled. Then, SFCL connected in series with transmission line during short-circuit fault systematically determined by applying equal-area criterion based on power-angle curves. To verify effectiveness proposed reducing current, several case studies are carried out...

GdBCO single-pancake coils wound with Kapton insulation every 3, 6, 9 turns, and without insulation, were characterized by charge–discharge over-current tests. The magnetic field saturation at higher currents than the critical current was affected portion of insulated turns that restricted surplus flow away from azimuthal path. delay decreased increase which suggested partial winding may be effective for use in HTS power applications. Magnetic loss reduced excessive high mainly decrease...

This study introduces 600-km/h wheel-type railway concept propelled by linear synchronous motor (LSM) and deals with the conceptual design for LSM system. The is designed to be of a coreless type, which uses high- T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> superconducting electromagnet (SC-EM) as on-board field magnet. From tentative train parameters, we suggest model its parameters achieve performances. As SC material, use...

This paper describes a study on the optimal location of resistive superconducting fault current limiter (SFCL) applied to an electric power grid. The SFCL, which is designed provide quick system protection in event fault, can have different effects planning and operation depending its location. To select sensitivity analysis changes and/or losses with respect value occurred series transmission line during introduced. Moreover, determined by proposed method coordinated corresponding SFCL...

This paper describes a operating characteristics of contactless power transfer (CPT) system from normal conducting coil to HTS based on the electromagnet resonance coupling. The basic principle is that two separate coils with same frequency are possible form resonant high magnetic coupling and exchange energy in efficiency. CPT technique electromagnetic has been expected as useful option for charge storage devices. Since technology using sensitive tune impedance matching, efficiency limited....

This paper deals with an analysis on the optimum lap joint method of YBCO coated conductor (CC) wire. Effective low resistance is important for development persistent current mode system using second generation high temperature superconducting (2G HTS) wire, CC. CC tape stacked copper or stainless steel stabilizer, silver layer, buffer and substrate. The between CCs was performed InBi solder. samples various contact conditions were fabricated tested. Characteristics jointed evaluated from...

This paper deals with fabrication and development of a high temperature superconducting (HTS) fault current limiter (FCL) based on YBCO coated conductor (CC) wire for distribution systems. The capacity the developed HTS FCL is 8.3 MVA its rated voltage 13.2 kV which corresponds to three-phase power equipment class 22.9 kV. Tests prototype were conducted at Korea Electrotechnology Research Institute (KERI) accredited as testing laboratory by Laboratory Accreditation Scheme (KOLAS). A...

In order to design a high temperature superconducting (HTS) winding for the fault current limiter (FCL), resistance and of should be calculated quantitatively under over-current caused by condition. this paper, transient analysis is performed estimate development rise coated conductor (CC) AC over-current. A one-dimensional thermal conduction model with an electrical circuit developed solenoid coil configuration at 65 K cooling All composite materials except buffer layer in CC are considered...

This paper deals with design and operating tests of prototype hybrid superconducting fault current limiter (SFCL) which is series connected non-inductive solenoid resistive coil asymmetric non-inductively wound coils. The role SFCL for reducing the in first swing. Moreover, can reduce a load dielectric strength SFCL. Two kinds high temperature superconductor (HTS) wires were used to fabricate HTS coil. These had different quench characteristics such as critical n-value. Unbalanced...

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...

Rotary HTS flux pumps are suitable for cryogenic applications, where it is difficult to implement direct physical connections between the device in question and an external power supply. Here we examine proportional-integral-derivative (PID) control of a rotary pump compensate change current field coil synchronous motor under operating conditions. The must be maintained constant prevent output fluctuation motor. In this context, prototype with rotating tape constructed study. A 600-turn...

As a part of the 21st Century Frontier R&D Program in Korea being performed from 2004, non-inductive winding type superconducting fault current limiter (SFCL) is developed. The target second year phase II program to develop 220 V/300 A class SFCL as prototype for 13.2 kV/630 class, final goal II. This has three solenoid non-inductively wound coils series using 2G high temperature (HTS) wire and it was tested sub-cooled nitrogen 65 K, 1 atm. coil which composed four parallel windings bobbin...

The power grid, especially distribution has been more complicated due to distributed generations (DGs) with renewable energy sources and the smart grid. complexity changes two things in terms of a fault; higher prospective fault current temporal variation loads. To correspond those remarkable changes, we propose controller (FCC) named “smart FCC.” FCC consists superconducting coil freewheeling diode if necessary, four thyristors, control unit. Smart can not only limit but also when occurs....

This paper presents the development status of joint method between superconducting YBCO coated conductors (YBCO CC). In general, YBCO-CC tape consists an upper stabilizer, substrate, buffer, and a bottom stabilizer. It is suggested that stabilizer two tapes need to be removed, in order improve characteristics joints. The removing process was conducted by using heat partial etching. resistance critical current joints were measured from curve. optical micrographs analyzed for microstructures...

Since resistive superconducting fault current limiters (SFCLs) are inserted to a power system directly, it is necessary recover instantly after the clearance of fault. Most SFCLs using BSCCO bulk or thick film have recovery time tens seconds. An SFCL YBCO coated conductor (CC) has large surface area contacted liquid nitrogen. Joule heat flux smaller than that other types when occurs. Therefore, important for employing CC investigate time. In this paper, characteristics with respect applied...

This paper deals with design and operating test of a novel hybrid FCL. The FCL system consists coil, fast switch resistor for bypassing the fault current. is driven by non-inductive coil suggested in this but an extra driving required existing We used two kinds HTS wire coil. impedance was negligible normal operation. But different quench characteristics wires caused asymmetric current distribution which induced effective magnetic flux during faults. opened repulsive force from response to...

The rotary flux-pump using HTS tape has been studied for superconducting rotating machinery application. charging speed and saturation current of the is closely related to magnetic flux linkage passing through tape. To analyze parameters that effect pumping rate flux-pump, methods changing speed, shape permanent magnet, width tape, intensity have investigated in previous studies [1]- [3]. In this paper, we tried test three cases investigate current: 1) two different background materials,...

Abstract This paper deals with the fabrication and performance testing of a prototype machine for world’s first implementation new type high-temperature superconducting rotating (HTSRM), which is charged operated by application contactless excitation technique rotary-type HTS flux pump based on permanent magnet. Although this has been actively applied in stationary applications, its practical demonstration rotary namely, machines, not yet conducted or reported. Therefore, laboratory-scale...

A superconducting fault current limiter (SFCL) using high temperature (HTS) wire has been developed in Korea. While the first-generation difficulty adopting various matrices because it is made by PIT process, second-generation flexibility design of its stabilizer. In general, coated conductor (CC) tape clad with a thick metal layer as stabilizer on such YBCO. addition, good electrical conductivity. However, resistive SFCL, when occurs, limits resistance Therefore, one most important parts...

Here we suggest stable maximum temperature criteria of YBCO coated conductors (CCs) considering degradation by repetitive exposure to excessive rise. Stable permissible was experimentally determined as the at which CC does not suffer from critical current or burnout. By comparing various over-current characteristics with short-circuit in regards pattern generated resistance and joule heating flux, rise superconducting fault limiter (SFCL) can be 400 K. Our research is expected provide...

The YBCO coated conductor (CC) is one of the most promising superconductors for various superconducting applications. Although it has many advantages, joints CC are inevitable because there technical difficulties in lengthening CC. In joining process, important to reduce joint resistance between CCs order operate a persistent current mode. Several approaches have been proposed eliminate stabilizer Among them, this paper introduces chemical etching method that can damaging influences...