• Progress in Superconductivity and Cryogenics
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• v.7 no.2
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• pp.16-20
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• 2005

As power systems grow more complex and power demands increase, the fault current tends to gradually increase. In the near future, the fault current will exceed a circuit breaker rating for some substations, which is an especially important issue in the Seoul metropolitan area because of its highly meshed configuration. Currently, the Korean power system is regulated by changing the 154kV system configuration from a loop connection to a radial system, by splitting the bus where load balance can be achieved, and by upgrading the circuit breaker rating. A development project applying 154kV Superconducting Fault Current Limiter (SFCL) to 154kV transmission systems is proceeding with implementation slated for after 2010. In this paper, SFCL is applied to reduce the fault current in power systems according to two different application schemes and their technical impacts are evaluated. The results indicate that both application schemes can regulate the fault current under the rating of circuit breaker, however, applying SFCL to the bus-tie location is much more appropriate from an economic view point.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.851-853
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• 1997

This paper presents an algorithm for real-time restoration of radially operated 154kV loop system. Restoration procedure consists of 4 procedures; recognition of faults, identification of fault locations, seperation of fault locations and restoration of blackout areas. This algorithm adopts expert's knowledge for safe and accurate operation of the real-time restoration system (APRS: Automatic Power Reconfiguration System).

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.334-336
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• 2003

This paper describes the influences of the large scaled wind farm interconnected with 154 kV power networks on the operational characteristics of distance relay applied in the transmission line. The wind farm composed of wind turbine generators are one of the great energy sources: they can supply the power into an interconnected network not only the normal conditions, but also the fault conditions of power network. Therefore, the distance relay applied in the transmission tine may mal-operate due to the contribution of wind farm. This paper presents the operational characteristics of distance relay for the fault occurred in the transmission line interconnected with wind farm. Simulation results show that it is difficult to recognize the fault location due to the power output of wind farm.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.752-753
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• 2007

154kV 초고압 케이블용 프리몰드 접속함은 기존의 접속 공법에 비해 부품수가 적으며 조립이 단순하여 숙련공이 아니라도 접속이 가능하고 높은 품질을 확보할 수 있어 앞으로 확대 사용될 것으로 예측된다. 신규개발에 따른 자재비의 일시적 상승은 있으나 전체 공사비가 절감될 뿐 아니라 케이블 접속공정의 단순화로 지중송전 케이블 접속분야 인력양성에 유리하며 접속작업 기간의 단축으로 케이블 고장발생시 신속한 복구를 통한 안정적인 전력공급에 크게 이바지 할 수 있다. 조립식접속함 분야는 이미 선진국에서 개발하여 널리 사용되고 있으며 후발업체에게 기술이전을 기피하기 위해 PQ조건등으로 후발업체를 강력하게 견제하고 있어 케이블 분야에 기술 자립을 이루고 수입대체 효과를 거두게 되었다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.438-439
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• 2011

Substations in Korea are classified into an outdoor steel structure type, an outdoor GIS(Gas Insulated Switchgear) type, an indoor GIS type, an underground GIS type, and a complex GIS type. Before 1970, substations were built in outdoor steel structure types only. In 1980, an 154kV indoor GIS type substation was built for the first time in Pusan. And the first 345kV indoor GIS type substation, the first 765kV full GIS substation were built in 1984 and in 2002 each. In 1998, 154kV indoor type substations were standardized into regular type and urban type which applied steel frames to structures. In 2002, this was re-standardized into five different types in detail. In 2007, hub substations which had high capacity were built in the region of industrial zone and heavy load areas. And 154kV compact substation was developed and standardized by compacting an indoor GIS type substation in 2009. This paper would present a series of substation type transition and application standards for substation types and facility scales.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.103-106
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• 2003

The short circuit current problem is one of the operational problems that need to be solved by power system engineers in Korea. It is an important issue in the Seoul metropolitan area especially because of highly meshed configuration. Currently, it is regulated by changing 154 kV system configuration from loop connection to radial system, by splitting of the bus where load balance can be achieved, and by upgrading circuit breaker rating. A development project for 154 kV/2 KA SFCL application to 154 kV transmission system after 2010 is proceeding. In this paper, a feasibility study of superconducting fault current limiter (SFCL) is carried out in Seoul metropolitan area to find out the effects of its application and feasibility. This study shows that it can reduce fault current considerably, and as it can minimize the upgrading of circuit breaker rating, the economic potential of SFCL is evaluated positively.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1659-1662
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• 1998

This paper is to analyze electromagnetic fields on a 154kV substation system and induced voltages on the substation fence when the network is operating in a normal condition or a fault condition in which one phase is shorted with the overhead ground wire. Also, changing the scalar potential and electromagnetic fields that are changed in accordance with changing resistivity and permeability of ground are studied. A finding of the study is that the scalar potential and electromagnetic fields are raised near the tower: The values of electric field on the corner of fence and at the edge of the ground grid are higher than other locations.

• Progress in Superconductivity and Cryogenics
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• v.12 no.3
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• pp.25-28
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• 2010

22.9 kV HTS cable and FCL will be installed in 154 kV Icheon substation. It is necessary to design a protection system of the substation for a successful application of the HTS devices. This paper proposes a new power protection system for the application of 22.9 kV HTS cable and SFCL to 154 kV Icheon substation in Korea.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.274-276
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• 1991

Since the successful development of 154kV XLPE cable in 1983, its commercial use has been drastically expanded due to technical advantages and high performance of insulation, Futhermore, the large conductor size of 1200ml and 2000ml has been mainly employed in Korea for the purpose of meeting the bulk power demand in urban area. However, it is highly required to solve the problems which can be occured at the level of the joints between the cables of different type such as between existing OF and XLPE cables.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.56-61
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• 2011

The temperature of power transformers is very important factor for power system operation in substation because load capacity and limited lifetime of power transformers are determined by winding temperature. Also, The temperature of power transformers varies with the structure, capacity, operation condition and manufacturers. Thus, it is necessary for temperature distribution to be exactly investigated because of efficient load management and prediction of limited lifetime. Nevertheless, there was no case of analysis as well as measurement of the temperature of power transformers. In this paper, we manufactured the 154kV standard power transformer for the test. And we measured the temperature by the heat run test and analyzed the temperature distribution of transformer.