• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.1
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• pp.10-14
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• 2001

The superconducting transmission cable is one of interesting part in power application using high temperature superconducting wire. One important parameter in HTS cable design is transport current sharing because it is related with current transmission capacity and loss. In this paper, we calculate self inductances of each layer and mutual inductances between two layers from magnetic field energy, and current sharing of each layer for 4-layer cable using the electric circuit model which contain inductance and resistance (by joint and AC loss). Also, transport current losses which are calculated by monoblock model and Norris equation are compared. As a results, outer layer has always larger transport current than inner layer, and current capacity of each layer is largely influenced by resistance per unit cable length. As a conclusion, for high current uniformity and low AC loss, we have to decrease inductances themselves or those differences.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.375-380
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• 2004

This paper presents the basic quench protection idea for the HTS(High-Temperature Superconducting) cable. In Korea power system, the transfer capability of transmission line is limited by the voltage stability, and HTS cable could be one of the countermeasure to solve the transfer limit as its higher current capacity and lower impedance[1]. However, the quench characteristic of HTS cable makes HTS cable to loss its superconductivity, and therefore change the impedance of the line and power system operating condition dramatically. This pheonominum threats not only HTS cable safety but also power system security, therefore a proper protection scheme and security control counterplan have to be established before HTS cable implementation. In this paper, the quench characteristics of HTS cable for the fault current based on heat balance equation was established and a proper protection method by FCL(Fault Current Limiter) was suggested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2316-2321
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• 2009

With rapid development of world economics, electricity demand in metropolitan area has been increased dramatically. HTS(High Temperature Superconducting) cable is one of most promising technology to solve the bottleneck of electric network. However, HTS cable is not considered as matured technology yet to power system planners because of its different characteristics with conventional metal conductors. This paper suggests the comparison results of HTS cable simulation and experiment on steady state operation, also give the simulation results on transient characteristics of HTS cable components. This results could devote not only to discuss the security of HTS cable operation, but also to design power system oriented HTS cable.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.10
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• pp.946-951
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• 2003

A high-Tc superconducting cable(HTS cable) is expected as an underground power line supplying the electrical power the densely populated city in future. The electrical insulation is very important for develop HTS cable system because it is operated a high voltage and in cryogenic temperature. We manufactured a mini-model cable and measured a tan$\delta$ of cable using schering bridge. The tan$\delta$ of PPLP was lower than that of Tyvek and Kraft at a given temperature, the tan$\delta$ of PPLP was 1.16${\times}$10-3. According to the increase of electric stress the tan$\delta$ increased because partial discharge occurred inside butt gap of mini-model cable. However, the tan$\delta$ decreased by increase of liquid nitrogen pressure. This reason is thought by decrease of part discharge between butt gap by increase of liquid nitrogen pressure.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1210-1212
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• 2005

High temperature superconducting(HTS) power cable system consists of HTS cable, termination and cryogenic system. And the HTS cable consists of the former, HTS phase conductor, electric insulation, HTS shield and cryostat. Taking the advantage of HTS shield, the cold dielectric has been adopted. The phase conductor and the shield have been designed to minimize the AC loss below 1W/m/phase. The former has been designed to transport the fault current of 25kA, at fault condition. This paper describes the design process of 22.9kV HTS cable considering AC losses at normal state and the stability at fault condition.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.555-557
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• 2003

As electric power transmission systems grow to supply the increasing electric power demand, transmission capacity is larger. but that's really difficult to secure the location for power transmission and distribution to user. The high temperature superconducting(HTS) cable is a method to solve this problem. But for applying to real systems, it needs to investigate the effect of HTS cable. The most important things is the investigation of fault condition. the fault on HTS cable include the quench state. When a fault occur in a circuit, three critical parameters(temperature, current density, magnetic field) exist. when one of these parameters exceeds the critical value, the superconducting becomes normal-conducting. f the cooling power is insufficient to recover the superconducting state, the normal-conducting zone expands. In order to solve these problem, this paper present simulate the quench state considering the over-current and over-voltage in the informal circuit and analyze the quench state.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.243-245
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• 2003

The method to fabricate the cryostat of superconducting cable is extrusion type which is used Aluminum ingot under high temperature such as 45$0^{\circ}C$ and the cryostat is formed above cable core and MLI layer. In this case, it is expected to occur thermal injury in cable core and MLI layer, so it is necessary to study to prevent thermal injury. So in this paper, using simulation on radiation and convection which are accompany with fabricating cryostat, it is suggested to reduce the thermal injury. By measuring simulation temperature and real temperature, it is possible to check the temperature on cable core and MLI layer and using these temperature, it is possible to predict whether thermal injury is occurred or not on cable core and MLI layer.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.1
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• pp.25-30
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• 2020

Three-phase multi-layer high temperature superconducting coaxial (TPMHTSC) cable is being actively studied due to advantages such as the reduction of the amount of superconducting wire usage and the miniaturization of the cable. The electrical characteristics of TPMHTSC cables differ from those of conventional superconducting cables, so sufficient analysis is required to apply them to the actual system. In this paper, the authors modeled 22.9 kV, 60 MVA TPMHTSC cable and analyzed the transient characteristics using a PSCAD/EMTDC-based simulation. As a result, when a fault current flows in TPMHTSC cable, most of the fault current is bypassed through the copper former layers. At this time, the total cable temperature increased by about 5 K. Through this study, we can verify the reliability of the TPMHTSC cable against the transient state, and it can be helpful for the practical application of the cable in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.367-368
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• 2009

BSCCO HTS(High Temperature Superconductor) could be applied to superconducting cable, magnet and motor, using its hight critical properties. Especially, superconducting cable has a hight possibility of practical use due to the possibility of low voltage and high capacity transmission caused by its lower power loss than copper cable. In this paper, the transport characteristics of BSCCO superconducting cable, according to the change of BSCCO superconducting cable's accident point at phase $0^{\circ}$ and $45^{\circ}C$, were analyzed and compared each other. Consequently, when the accident was occur the resistance of the HTS was higher at the point phase $0^{\circ}$ than $45^{\circ}$ which means it will cause much higher load on the HTS.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.1
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• pp.15-20
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• 2004

This paper discusses electrical insulation characteristics at cryogenic temperature, especially focusing on partial discharge (PD) inception characteristics, for high temperature superconducting cables. In liquid nitrogen (L$N_2$) / polypropylene (PP) laminated paper composite insulation system, PD inception strength (PDIE) was evaluated in terms of volume effect and V-t characteristics. Different kinds of butt gap condition were applied in the experiments, using parallel plane and coaxial cylindrical cable samples. Experimental results revealed that the volume effect on PDIE could be evaluated by the statistical stressed liquid volume (SSLV) taking account the discharge probability not only in the butt gap but also in the other thin layers between PP laminated papers. Furthermore, the indices n of V-t characteristics at PD inception were estimated to be 80∼110, irrespective of the butt gap condition.