• Progress in Superconductivity and Cryogenics
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• v.22 no.4
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• pp.31-39
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• 2020

Power cables made of high temperature superconductors (HTS) are considered as most advanced applications of superconductivity for electro-energetics. Several cables made of the First Generation (1G) HTS wires have been produced and installed to electrical grids worldwide. Power cables made of the Second Generation HTS wires (2G or Coated Conductors) are in active development. Most basic principles of HTS power cables development have been published in many works since 90-ties. In this Review we would like to present our new developments mostly directed to 2G HTS compact power cables. We are presenting the methods to optimize a design of 2G AC compact power cable providing uniform current distribution among cable layers and the production technology approaches to implement such a design. AC losses measurements in such cables and other test methods are described. Some problems of the development 2G HTS power cables with small diameters are discussed. We presented as examples designs, developments and test results of two major coaxial cables designs: single-phase (cable core and a shield) and three-phase (triaxial: with three coaxial phases).

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.61-66
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• 2007

A transmission class high-temperature superconducting(HTS) power cable system is being developed in Korea. For insulation design of this cable the grading method of insulating paper is proposed. Two kinds of laminated polypropylene paper that has different thickness has been used as the electrical insulation material. The use of graded insulation gives improved mechanical bending properties of the cable. In a HTS cable technology the terminations are important components. A HTS cable termination is energized with the line-to-ground voltage between the coaxial center and outer surrounding conductors. in the axial direction. There is also a temperature difference from ambient to about 77 K. For insulation design of this termination, glass fiber reinforced plastic(GFRP) was used as the insulation material of the termination body, and the capacitance-graded method is proposed. This paper will report on the experimental investigations on impulse breakdown and surface flashover characteristics of the insulation materials for insulation design of a transmission class HTS power cable and termination. Based on these experimental data, the electrical insulation design of a transmission class HTS power cable and termination was carried out.

• Progress in Superconductivity and Cryogenics
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• v.8 no.2
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• pp.46-49
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• 2006

The 30m, 3phase, 22.9kV HTS (High Temperature Superconducting) power cable system was produced by LS Cable Ltd. The project aims for a commercial HTS cable. The designing, the manufacturing and the initial operating of HTS cable system were completed by 2004. Then, we have performed a long term operational test since February, 2005. This paper mainly reports the result of the HTS cable cooling operation.

• Progress in Superconductivity and Cryogenics
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• v.8 no.1
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• pp.29-33
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• 2006

A 154 kV class high temperature superconducting (HTS) power cable system is developing in Korea. For insulation design or this cable, the grading method of insulating paper is proposed. The use of graded insulation gives improved bending properties of the cable. Therefore, we discussed the electrical stress distribution and calculation for grading insulation design of a HTS cable. Also. the basic insulation design of 154 kV class HTS power cable was done.

• 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.

• Progress in Superconductivity and Cryogenics
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• v.22 no.1
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• pp.7-11
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• 2020

As demand for electricity in urban areas increases, it is necessary to improve electric power stability by interconnecting neighboring substations and high temperature superconductor (HTS) power cables are considered as a promising option due to its large power capacity. However, the interconnection of substations reduces grid impedance and expected fault current is over 45 kA, which exceeds the capacity of a circuit breaker in Korean grid. To reduce the fault current below 45 kA, a HTS power cable having a fault current limiting (FCL) function is considered by as a feasible solution for the interconnection of substations. In this study, a FCL HTS power cable of 600 MVA/154 kV, transmission level class, is considered to reduce the fault current from 63 kA to less than 45 kA by generating an impedance over 1 Ωwhen the fault current is induced. For the thermal design of FCL HTS power cable, a parametric study is conducted to meet a required temperature limit and impedance by modifying the cable core from usual HTS power cables which are designed to bypass the fault current through cable former. The analysis results give a minimum cable length and an area of stainless steel former to suppress the temperature of cable below a design limit.

• Progress in Superconductivity and Cryogenics
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• v.12 no.4
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• pp.24-30
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• 2010

The renewable energy source is considered as a good measure to cope with the global warming problem and the fossil energy exhaustion. The construction of electric power plant such as an offshore wind farm is rapidly increasing and this trend is expected to be continued during this century. The bulky and long distance power transmission media is essential to support and promote the sustainable expansion of renewable energy source. DC power cable is generally considered as the best solution and the demand for DC electric power has been rapidly increasing. Especially, the high temperature superconducting (HTS) DC cable system begins to make a mark because of its advantages of huge power transmission capacity, low transmission loss and other environmental friendly aspects. Technical contents of DC HTS cable system are very similar to those of AC HTS cable system. However the DC HTS cable can be operated near its critical current if the heat generation is insignificant, while the operating current of AC HTS cable is generally selected at about 50~70% of the critical current because of AC loss. We chose the specifications of the cable core of 'Tres Amigas' project as an example for our study and investigated the heat generation when the DC HTS cable operated near the critical current by some electric and thermal analyses. In this paper, we listed some technical issues on the design of the DC HTS cable core and described the process of the cable core design. And the results of examination on the current capacity, heat generation, harmonic loss and current distribution properties of the DC HTS cable are introduced.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.640-645
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• 2006

A 22.9kV/50MVA class high temperature superconducting(HTS) power cable system was developed in Korea. For the optimization of electrical insulation design for a HTS cable, it is necessary to investigate the ac breakdown impulse breakdown and partial discharge inception stress of the liquid nitrogen/laminated polypropylene paper(LPP) composite insulation system. They were used to insulation design of the model cable for a 22.9kV class HTS power cable and the model cable was manufactured. The insulation test of the manufactured model cable was evaluated in various conditions and was satisfied standard technical specification in Korea. Base on these experimental data, the single and 3 phase HTS cable of a prototype were manufactured and verified.

• 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.

• Progress in Superconductivity and Cryogenics
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• v.11 no.2
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• pp.25-28
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• 2009

A 154kV class high-temperature superconducting (HTS) power cable system is developing in Korea. For insulation design of this cable, it is important that study on cryogenic electrical insulation design to develop the cold dielectric type HTS cable because the cable is operated under the high voltage environment in cryogenic temperature. Therefore, this paper describes a design method for the electrical insulation layer of the cold dielectric type HTS cable adopting the partial discharge-free design under ac stress, based on the experimental results such a ac breakdown strength, partial discharge inception stress, $V_{ac}$-t characteristics, $V_{imp}$-n characteristics, and impulse breakdown strength of liquid nitrogen/laminated polypropylene paper (LPP) composite insulation system in which the mini-model cable is immersed into pressurized liquid nitrogen.