• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.169-170
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• 2008

최근 전력수요의 증가 및 부하 고밀도화에 효과적으로 대응하고 배전설비 투자비용의 절감을 통한 경영효율성 증진을 위해 전배전선로를 대상으로 배전선로의 상시운전용량과 비상시운전용량을 상향조정하였다. 도심번화가 공단 등 부하밀집지역, 선로전압 유지곤란지역 및 경과지 확보가 곤란한 지역에 대용량 배전방식을 채택하여 운영하고 있다. 이와 같은 배전계통 운전 용량의 큰 변화에 따라 전력회사에서는 일선사업소의 모든 배전계획자들이 배전계획 및 운영시 배전계통의 설비를 가장 효율적으로 이용할 수 있도록 모든 배전선로에 대하여 배전용변전소, 주변압기, 인접 2회선 등의 상정사고 및 작업시에도 건전정전구간이 발생하지 않도록 부하를 융통할 수 있는 연계 기준이 마련되어 있다. 본 논문에서는 배전선로의 루프운전의 조건가능 여부를 보다 정확하고 신속한 방법으로 사전에 검토하여 고장을 예방하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2046-2048
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• 2005

This paper deals with ground potential rise of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage in concrete attached to structure, the potential distribution of ground surface appeared differently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.19-21
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• 2002

Recently, it has become more competitive to take larger market share among domestic companies manufacturing high-power apparatus. Unfortunately, the size of total market in this field is being smaller than before because the business of transmission and distribution of electric power is being shifted from government control to private management. To save this situation, we are trying to develop new high-voltage Gas Insulated Switchgear for export such as 245kV GIS and 300kV GIS. It is very important to make GIS compact size to have international competitiveness against European companies. By reducing GIS's dimensions same as 170kV class, we expect to launch abroad successfully. Many factors should be considered to achieve good performance during short-circuit making-breaking. Analysis on cold gas flow is one method widely used to evaluate small-current interruption. Through this analysis, we can examine the dielectric characteristics at the weak points in the circuit-breaker. In this paper, we describe the results of cold-gas flow analyses on 245kV and 300kV circuit-breakers.

• 산업경영시스템학회지
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• 제20권44호
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• pp.33-46
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• 1997

The location decision problem for distribution center is one of the most important problem in business logistics system. Because the proportion of holding and transportation cost to physical distribution cost in our country exceed the 60%, a corporation must feel strong pressure to investigate the location problem for distribution center. This paper presents an algorithm for determining the best location of distribution center in consideration with physical distribution cost, demand, and customer location. The methods of determining the distribution center location is that firstly many of proposed sites are built up where demand position is distributed, and then optimal location of distribution center is selected.

• KEPCO Journal on Electric Power and Energy
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• 제5권2호
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• pp.67-74
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• 2019

최근 신재생 분산전원의 투입 확대로 배전계통 내 변동성이 커짐에 따라서 안정적인 배전계통 운영에 대한 우려가 커지고 있는 상황이다. 미래 배전계통의 효율적인 관리를 위해서 새로운 시각화 기술을 이용한 배전계통 운영시스템의 개선이 필요하다. 본 논문에서는 배전분야의 GIS 도입 현황과 관련 기술 동향을 기술하고, 배전계통 운영을 위해 GIS시스템의 필요성과 GIS기술 도입 시 해결해야할 문제점을 분석한다.

• 한국기계가공학회지
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• 제13권5호
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• pp.15-20
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• 2014

The wind industry grew in the first decade of the 21st century at rates consistently above 20% a year. For wind turbine, gearbox failure can be extremely costly in terms of repair costs, replacement parts, and in lost power production due to downtime. In this paper, gear tooth micro-modification for the high speed stage was used to compensate for the deformation of the teeth due to load and to ensure a proper meshing to achieve an optimized tooth contact pattern. The gearbox was firstly modeled in a software, and then the various combined tooth modification were presented, and the prediction of transmission under the loaded torque for the helical gear pair was investigated, the normal load distribution and root stress were also obtained and compared before and after tooth modification under one torque. The simulation results showed that the transmission error and normal load distribution under the load can be minimized by the appropriate tooth modification. It is a good approach where the simulated result is used to improve the design before the prototype is available for the test.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.519-526
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• 2010

The construction site for $\bigcirc\bigcirc$ transformer substation was located at a mountain valley. In order to prepare the site, the valley was first filled with crushed rock debris up to 63m. Since the main concern of this project is to minimize differential settlement of the foundation of transformer facilities, dynamic compaction was performed every 7m followed by reinforcement with EMP(Ez-Mud Piling). The EMP is one of bored piling methods, in which a hole is bored by means of air percussion and maintain by injecting Ez-Mud. Then a PHC pile (Pretensioned spun High strength Concrete pile) is embedded and finalized with a hammer. In this study, bearing capacities and long term behavior of a pile installed by EMP were investigated. To achieve these objectives, a series of tests such as static and dynamic load tests were conducted. In addition, a construction quality control standard was proposed based on the test results.

• 터널과지하공간
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• 제24권4호
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• pp.275-281
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• 2014

국내 국도에 분포하는 160개 비탈면에서의 발생한 낙석에너지의 특성을 고려하여 신뢰도지수를 산정하고 낙석방지울타리의 요구성능을 고찰하였다. 몬테카를로 시뮬레이션을 통해 낙석에너지를 결정하는 변수의 통계적 특성을 고찰한 결과 비탈면 경사는 정규분포형태이며, 낙석중량과 발생높이는 대수정규분포형태인 것으로 나타났다. 낙석에너지는 대수정규분포형태인 것으로 나타났으며 이는 낙석중량에 영향을 받은 결과로 판단된다. 낙석방지울타리의 신뢰성지수는 0.678이며 파괴확률은 24.9%로 매우 높은 것으로 나타났다. 국내의 낙석에너지 규모를 고려하여 제시된 낙석방지울타리의 요구성능은 최대 500kJ 수준이며 신뢰성지수의 범위는 1.028~1.956으로 분석되었다. 제시된 신뢰도지수를 통해 비탈면의 낙석에너지가 고려된 요구성능을 적용할 경우 낙석방지울타리의 파괴확률은 14.8~2.5% 수준인 것으로 분석되었다.

• 한국가스학회지
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• 제17권5호
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• pp.51-57
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• 2013

최근 들어 다양한 재료 및 제조기술의 개발로 가스관 품질이 향상되어 매설심도를 저심도화 할 수 있는 환경이 조성되고 있다. 또한 선진 외국과 비교하여 국내 매설깊이 기준이 약 50cm 정도 깊은 것으로 조사되어 시공비용, 차량지체비용 등을 고려하였을 때 비효율적인 매설깊이 규정인 것으로 판단된다. 따라서 본 연구에서는 매설깊이 변화(0.8m, 1.0m, 1.2m)에 따른 가스관의 응력 및 변형 거동을 분석하였다. 본 연구에서는 수치해석 및 현장시험을 통하여 매설심도 변화에 따른 가스관(API 5L)의 거동특성을 분석하였다. 분석결과, 매설심도의 감소가 가스관의 응력, 변형 특성에 큰 영향을 미치지 않을 것으로 판단되었다.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.5-7
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• 2022

KEPCO's plan is undergoing a trial operation to replace the open-loop section with ring main units configuration where underground distribution lines are installed, by linking the multi-way circuit breakers auto (MCA) on the power side of each pad-mounted transformer. However, ring main units application mentioned above may cause the ripple effects, when implementing the configuration without a study of protection coordination. Because ring main units with classical pre-set protection devices contribution in fault condition didn't consider yet. For the reliable ring main units operation, it is necessary to resolve several protection issues such as the protection coordination with substation side, prevention of the transformer inrush current. These issues can radically deteriorate the distribution system reliability Hence, it is essential to design proper protection coordination to reduce these types of problems. This paper presents a scheme of ring main units' configuration and MCA's settings of time-current curves to preserve the performance of protection coordination among the switchgears considering constraints, e.g. prevention of the ripple effects (on the branch section when a transformer failure occurs and the mainline when a branch line failure occurs). It was confirmed that the propagation of the failure for each interrupter segment could be minimized by applying the proposed TCC and the interrupter settings for the MCAs (branch, transformer). Further, it was verified that the undetected area of the distribution automation system (DAS) could be supplemented by having the MCA configurated ring main units operate first, instead of the internal protection equipment in the transformer such as the fuse, STP when a transformer failure occurs.