• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.740-741
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• 2007

This paper analyses the transient state of underground distribution system against single line to ground fault in underground transmission systems, when underground transmission systems and distribution systems are made of common grounding. Underground transmission systems and distribution systems are modeled by EMTP/ATPDraw. Simulation is carried out considering variation of parameters such as value of common grounding, balance load and unbalance load.

• Geomechanics and Engineering
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• 제5권2호
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• pp.99-118
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• 2013

Construction of the extension project of the Bangkok MRT Blue Line underground railway was recently started in 2011. The construction of approximately 5 km long underground tunnel and 4 deep excavations of underground station are considered to be the most important geotechnical works. The pressuremeter was selected as a high-quality in situ testing of the soil to evaluate design parameters for the project. In addition, other field and laboratory tests such as vane shear and $CK_0U$ triaxial tests were included in the investigation programme. This paper aims to present the ground conditions encountered along the MRT Blue Line extension project as well as the site investigation and interpretation techniques with particular focus on the pressuremeter tests. The results are also compared with the pressuremeter investigation from the previous Bangkok MRT project.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.459-461
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• 2005

This paper analyses the induced voltage characteristic of CCPU with unbalanced current from distribution line on underground transmission power cable systems. In switching surge strokes, in order to obtain the data of induced voltage/current on CCPU, the actual proof test carried out. This paper is expected to contribute the establishment of proper protection methods of CCPU against the unbalanced current from distribution line on underground transmission power cable systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.226-229
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• 2001

The combined transmission lines with the underground power cables are continuously expanded in power systems. So the fault of combined transmission line is increased every year as the complication of underground transmission line. In this paper. traveling wave theory and DWT wavelet transform are used for fast and accurate detection of fault location at the combined transmission line. Traveling wave travels to each bus like surge and repeats reflection and transmission till transient signal is completely disappeared. When fault is occurred on overhead and underground tine, the fault location detecting algorithm was performed with using continuous peak value time-delay of traveling wave reflected from A bus.

• Spatial Information Research
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• 제5권1호
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• pp.115-131
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• 1997

지하매설물은 지방자치단체, 통신공사, 전력공사, 도시가스회사, 지역난방공사 등 관리주체가 다양하며, 서로 다른 기본도 사용에 따른 중복투자발생, 관리부서별 다양한 도면 및 대장자료의 산재, 다양한 관리기관별 업무협조체제의 부재로 인해 통합된 정보부재 등의 문제를 안고 있다. 선진외국에서 GIS를 이용하여 지하매설물을 체계적으로 관리하고, 도시안전관리에도 기여함을 고려할 때, 지하매설물의 효율적 관리방안으로서 GIS 도입에 대한 연구가 절실함을 느낀다. 본 연구에서는 첫째 지하매설물 관리기관별 지하매설물 관리실태를 파악하고 둘째 서울시 지하매설물 관련기관에서 사용할 수 있는 확장성있는 데이터베이스 표준안을 작성하였으며 셋째 지하매설물 데이터베이스 구축에 있어 탐사에 의한 방법과 기존의 각 관리기관에서 보유하고 있는 도면을 이용하는 방법에 대한 가능성 검증 및 기존도면을 이용하여 데이터베이스를 구축하는 경우의 입력절차를 제안하고, 넷째 데이터베이스 구축 후 유지관리를 위한 방안에 대한 대안을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.349-351
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• 2001

Because of the continuous growth of energy consumption and also the tendency to site power lines and pipelines along the same route, the close proximity of power lines and buried metallic pipelines has become more and more frequent. Therefore there has been and still is a growing concern about possible hazards resulting from the influence of power lines on metallic pipelines. When a ground fault occurs in an electrical installation the current flowing through the earthing electrode produces a potential rise of the electrode and of the neighbouring soil with regard to a remote earth. This paper analyzes the effects of ground faults when the current will flow into the soil from the foot of 345kV transmission line tower.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.376-378
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• 2003

Since the first underground transmission line of Korea was installed between Danginri and Yongsan substations in 1974, the two types of underground transmission power cables, oil-filled and XLPE, have been applied for underground transmission lines. As the manufacturing technologies of XLPE cable have been improved and the simplicity of installation and maintenance has been focused on, the installations of XLPE cables have been largely increased since the mid 1990's. For the first time, in Korea, the 345kV XLPE cable was installed between Youngseo and Youngdeungpo substations in 2003, June. So, this paper introduces the project profile, the design of cable and its accessory, the cable system design, installation and site test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1815-1817
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• 2003

Since the first underground transmission line in Korea was installed in 1974, the two types of underground transmission power cables, oil-filled and XLPE, have been applied for underground transmission lines. As the manufacturing technologies of XLPE cable have been improved and the simplicity of installation and maintenance has been focused on, the installations of XLPE cables have been largely increased since the mid 1990's. For the first time, in Korea, the 345kV XLPE cable was installed at Pyungtaek thermal power plant in 2003, February. So, this paper introduces the project profile, the design of cable and its accessory, the cable system design, installation and site test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.440-442
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• 2000

This paper describes the digital distance algorithm in case of combined transmission line connected with overhead line and underground cable. Actually as fault is occurred in cable, it results in the complicated phenomena due to the several kind of grounding method in the sheath of cable. Accordingly the impedance. Therefore the correct impedance calculation algorithm is requested in combined transmission line to avoid the wrong trip of relay. This paper presents the development result of impedance calculation algorithm In such transmission line.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1845-1850
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• 2003

The underground utility tunnels are important facility as a mainstay of country because of communication developments. The communication and electrical duct banks as well as various utility lines for urban life are installed in the underground utility tunnel systems. If a fire breaks out in this life-line tunnel, the function of the city will be discontinued and the huge damages are occurred. In order to improve the safety of life-line tunnel systems and the fire detection, the behaviors of the fire-induced smoke flow and temperature distribution are investigated. In this study we assumed that the fire is occurred at the contact or connection points of cable. Numerical calculations are carried out using different velocity of ventilation in utility tunnel. The fire source is modeled as a volumetric heat source. Three-dimensional flow and thermal characteristics in the underground tunnel are solved by means of FVM (Finite Volume Method) using SIMPLE algorithm and standard ${\kappa}-{\varepsilon}$ model for Reynolds stress terms. The numerical results of the fire-induced flow characteristics in an underground utility tunnel with different velocity of ventilation are graphically prepared and discussed.