• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.585-587
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• 1998

In 22.9 kV-Y distribution lines, Several kinds of over-voltages occur. These over-voltages are usually surge types except controling the bus voltages for line voltage drop. The measuring over-voltages in 22.9 kV lines is a very difficulty skill. This paper introduces the study on the measurement system of over-voltages in 22.9kV distribution lines. It has been researching in KEPCO since 1995.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.3
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• pp.223-231
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• 1990

Optimal Power Flow (OPF) solution by the Newton's method provides a reliable and robust method to classical OPF problems. The major challenge in algorithm development is to identify the binding inequalities efficiently. This paper proposes a simple strategy to identify the binding set. From the mechanism of penalty shifting with soft penalty in trial iteration, an active binding set is identidied automatically. This paper also suggests a technique to solve the linear system whose coefficients are presented in the matrix from. This implementation is highly efficient for sparsity programming. Case studies for 3, 5, 14, 118 bus and practical TPC-190, KEPCO-306 bus systems are performed as well.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.115-117
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• 2005

If obstacle in GIS(Gas Insulted Switchgear), its affects are great are on the community and it is consequently demanded lots of difficulities to recover and repair. Accordingly, diagnosis techniques, that are able to prevent from accidents before they happen by providing more stable and highly reliable power effectively and finding sign of the accidents is very important. A novel UHF(Ultra High Frequency)-microstrip antenna is presented. The measured impedance bandwidth of the proposed antenna is from 0.5[GHz] to 15[GHz] with the stop band from 0.5[GHz] to 10.7[GHz] for VSWR<2. Form results of this study, The antenna is will play an important role for the sensor for insulation diagnosis system by UHF method of real site GIS and power equipment using $SF_6$ gas.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1858-1860
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• 2003

Ground rods as the discharge path are commonly installed to ensure the safety of human beings and facilities from the surge. Accordingly, proper grounding resistance are specified by the grounding types, and the specified resistance are also required to install the lightning protective facilities. it is needed to analyze the difference between these two resistance through the field test. Therefore, in this paper, the impulse response behavior of the ground rods is analyzed by constructing the test facilities and by testing the ground rods in multi-ground power distribution systems. The impulse responses were analyzed, in transient state, by testing the concrete poles as well since the grounding wires are installed in the concrete poles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.244-245
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• 2007

Specially, High Temperature Superconducting power-transmission cable(HTS cable), 3-phase 100m long, 22.9kV class HTS power transmission cable system have been developed by Korea Electrotechnology Research Institute (KERI) and LS cable Ltd. that is one of 21st century frontier project in Korea. This cable was installed in KEPCO(Go-chang) testing site. In case of manufacturing HTS cable, superconducting joint is very important because they need very long tapes. Therefore, this paper gives some investigation of AC Loss in joined HTS tape by using several joint methods. Finally, this paper was shown background data for the form of HTS cable joint.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.931-932
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• 2007

Specially, High Temperature Superconducting power-transmission cable(HTS cable), 3-phase 100m long, 22.9kV class HTS power transmission cable system have been developed by Korea Electrotechnology Research Institute (KERI) and LS cable Ltd. that is one of 21st century frontier project in Korea. This cable was installed in KEPCO(Go-chang) testing site. In case of manufacturing HTS cable, superconducting joint is very important because they need very long tapes. Therefore, this paper gives some investigation of AC Loss in joined HTS tape by using several joint methods. Finally, this paper was shown background data for the form of HTS cable joint.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.198-200
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• 2004

The purpose of this paper is to explain improvement of voltage stability using STATCOM by active power margin and reactive power margin. STATCOM, the representative shunt compensator of the FACTS devices, is faster than machinery compensator in response speed and has the advantage of the small scale because it doesn't use reactor or large capacitor. In this paper, we investigated the compensatory effect of the STATCOM that applied to KEPCO system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.8-12
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• 2019

Combined Cycle Unit(CC) generates the primary power from the Gas Turbine(GT) and supplies the remaining heat of the GT to the Steam Turbine(ST) to generate the secondary power from the ST. It plays a major role in terms of energy efficiency and Load Frequency Control(LFC). Incremental Heat Rate(IHR) curves of economic dispatch(ED) of CC is applied differently by GT/ST combination. But It is practically difficult because of performance test by all combinations. This paper suggests a reasonable method for estimating IHR curves for partial combinations(1:1~(N-1):1) using IHR curves when operating with GT alone(1:0) and with all(N:1) combinations of CC.

• Journal of Radiation Industry
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• v.17 no.3
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• pp.265-273
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• 2023

To effectively and safely manage the radiation exposure to nuclear power plant (NPP) workers in accidents, major overseas NPP operators such as the United States, Germany, and France have developed and applied realistic 3D model radiation dose assessment software for workers. Continuous research and development have recently been conducted, such as performing NPP accident management using 3D-VR based on As Low As Reasonably Achievable (ALARA) planning tool. In line with this global trend, it is also required to secure technology to manage radiation exposure of workers in Korea efficiently. Therefore, in this paper, it is described the application method and assessment results of radiation exposure scenarios for workers in response to accidents assessment technology, which is one of the fundamental technologies for constructing a realistic platform to be utilized for radiation exposure prediction, diagnosis, management, and training simulations following accidents. First, the post-accident sampling after the Loss of Coolant Accident(LOCA) was selected as the accident and response scenario, and the assessment area related to this work was established. Subsequently, the structures within the assessment area were modeled using MCNP, and the radiation source of the equipment was inputted. Based on this, the radiation dose distribution in the assessment area was assessed. Afterward, considering the three principles of external radiation protection (time, distance, and shielding) detailed work scenarios were developed by varying the number of workers, the presence or absence of a shield, and the location of the shield. The radiation exposure doses received by workers were compared and analyzed for each scenario, and based on the results, the optimal accident response scenario was derived. The results of this study plan to be utilized as a fundamental technology to ensure the safety of workers through simulations targeting various reactor types and accident response scenarios in the future. Furthermore, it is expected to secure the possibility of developing a data-based ALARA decision support system for predicting radiation exposure dose at NPP sites.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.329-334
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• 2012

The distribution submarine cables are normally used for power supply at island, which are mostly installed in the southern coast of KOREA, and partially installed in the west coast and Jeju-Island. There are two way of submarine cable burying system, buried and unburied type. Since 2003, KEPCO is entirely being constructing the distribution submarine cable by buried type. In this case, 'burial depth' is key index for evaluating the suitability of the buried situation. Therefore, the measurement accuracy of 'burial depth' is a big issue for burying system in the distribution submarine cable. This paper demonstrates the measurement error of burial depth that is affected by electrical factor such as grounding type of submarine cable in case of magnetic field detection method, and indicates the method to reduce the measurement error in buried type of distribution submarine cable system.