• Proceedings of the KIEE Conference
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• summer
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• pp.91-93
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• 2004

This paper is to develope the fast screening algorithm for on line transient security assessment. All generators are represented in a classical model and stability index is defined as a ratio between acceleration power and deceleration power Critical machines and remaining machines are identified based on stability index and aggregated into two equivalent machines. And finally equivalent machines are reduced into OMIB system then CCT is computed. The Proposed algorithm is applied to the KEPCO system and obtained the reasonable results compared with TSA Tool.

• Corrosion Science and Technology
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• v.20 no.1
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• pp.1-6
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• 2021

Many Korean industrial plants including nuclear and fossil power plants use seawater as the ultimate heat sink to cool the heat generated by various facilities. Owing to the high corrosivity of seawater, facilities and piping made of metal material in contact with seawater are coated or lined with polymeric materials to avoid direct contact with seawater. However, polymeric materials used as coating and lining have some level of permeability to water and are degraded over time. Korean industrial plants have also experienced a gradual increase in the frequency of damage to pipes in seawater systems due to prolonged operating periods. In the event of a cavitation-like phenomenon, coating or lining inside the piping is likely to be damaged faster than expected. In this paper, the cause of water leakage due to base metal damage caused by the failure of the polyester lining in seawater system piping was assessed and the experience with establishing countermeasures to prevent such damage was described.

• Progress in Superconductivity and Cryogenics
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• v.12 no.3
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• pp.39-43
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• 2010

In Korea, 22.9kV hybrid SFCL (Superconducting Fault Current Limiter) has been developed and carried out long-term field tests in Gochagn power test center of KEPCO through DAPAS program. The SFCL will be installed at a distribution line of Icheon substation in Korea. For the successful application, we have to design the specifications considering real power system operation. This paper proposes a concept of the operating current based rms value for the protection coordination with protective delays and studies a proper range of the current in Korean distribution power system.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.778-779
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• 2023

본 논문은 어린이의 불편함을 해소하며 카시트 사용율을 증가시키기 위해 어린이의 안전한 이동과 편의를 제공하는 '어린이 교통안전 위한 자동 방향 전환 스마트 카시트'를 제안한다. 주요 특징은 다음과 같다. 첫째, 카시트에 자녀를 태우고 내리는 과정이 편리하도록 승하차 모드를 제공한다. 둘째, 상황에 맞게 정방향, 역방향 전환이 가능하다. 셋째, 운전자가 운전에 집중할 수 있도록 음성인식으로 모드를 전환할 수 있다. 넷째, 수면인식을 하여 어린이가 차안에서 편안하게 잘 수 있도록 햇빛가리개를 작동한다. 다섯째, 흔들린 아이 증후군 방지를 위해 카시트의 높이와 너비를 조절할 수 있다.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.157-162
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• 2015

Large scale superconducting magnetic energy storage (SMES) system requires very high magnetic energy density in its superconducting coils to enhance the energy capacity and efficiency of the system. The recent high temperature superconducting (HTS) conductors, so called 2G conductors, show very good performance under very high magnetic field so that they seem to be perfect materials for the large scale SMES coils. A general shape of the coil system with the 2G HTS conductor has been a tor oid, because the magnetic field applied perpendicularly to the surface of the 2G HTS conductor could be minimized in this shape of coil. However, a toroid coil requires a 3-dimensional computation to acquire the characteristics of its critical current density - magnetic field relations which needs very complicated numerical calculation, very high computer specification, and long calculation time. In this paper, we suggested an analytic and statistical calculation method to acquire the maximum magnetic flux density applied perpendicularly to the surface of the 2G HTS conductor and the stored energy in the toroid coil system. Although the result with this method includes some errors but we could reduce these errors within 5 percent to get a reasonable estimation of the important parameters for design process of the HTS toroid coil system. As a result, the calculation time by the suggested method could be reduced to 0.1 percent of that by the 3-dimensional numerical calculation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.3
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• pp.129-139
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• 1999

This paper presents the operation teclmology and the rerrote rmnitoring system of distribution pole transfonrer. Especially, this system uses cable 1V network as communication m:dia which is located in KEPCO's main distribution line. It has fom major components such as sensor for measuring the secondary voltage and currents of distribution transfonrer, RF modernfor data modulating/de-modulating, connnunication media for sending/receiving of data, and PC server for monitoring the results of sensing or computing information. This paper also describes the configuration of each component'sfunctions with its development process. In addition, the reliability and effectiveness of proposed system was confimed by aoolving this remote monitoring system to Jungbu branch area.h area.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.659-663
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• 2012

The application of large power transformer into a power distribution system was inevitable due to the increase of power demand and distributed generation. However, the decrease of the power transformer's impedance caused the short-circuit current of the power distribution system to be increase thus, the higher short-circuit current exceeded the cut-off ratings of the protective devices such as circuit breaker. To solve these problems, several countermeasures have been proposed to protect the power system effectively from higher fault current and the superconducting fault current limiter (SFCL) has been expected to be the promising countermeasure. In spite of excellent current limiting performances of the SFCL, on the other hand, the efforts to apply the SFCL into power system has been delayed due to both the limited spaces for the SFCL's installation and its long recovery time after the fault removal. In order to solve these problems, a hybrid SFCL, which can perform either first half cycle limiting of first half cycle non-limiting operation, has been developed by corporation of LSIS (LS Industrial System) and KEPCO (Korea Electric Power Corporation). In this paper, we tried to requirements hybrid SFCL by PSCAD/EMTDC. Simulation results of our analysis of the hybrid SFCL is that its accompanied the characteristics both the limit the fault current and quick recovery caused by the less impact from superconductor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1577-1582
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• 2016

Now we are facing severe environmental issues such as global warming. Due to these, the concerns about eco-friendly energy have been increased. Kyoto protocol and Copenhagen climate change conference are circumstantial evidence of it. With these trends, the interests for the Electric Vehicles(EVs) which do not emit any harmful gases have gradually been raised. Unfortunately, however, massive connection of EVs to the power system could cause negative impacts such as voltage variations, frequency variations and increase of demand power. To prevent the mentioned issues, KEPCO adopts Time-of-Use(ToU) price for EVs charging. Nevertheless, it is important to verify the propriety of the charging system. In this paper, therefore, we used pre-introduced price elasticity concept to predict possible Demand Response(DR) on charging of EVs. And analyzed possible demand power increase according to various price elasticities. Simulation results show that given ToU based charging system would not enough to control the increase of demand power by EVs on the power system. It is concluded, therefore, additional methods and/or algorithms are required.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.263-269
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• 2009

This paper describes comparative analysis results about the dynamic interaction of interconnected wind power system using the actual-size hardware simulator and the simulation model with PSCAD/EMTDC. The hardware simulator, which is composed of 2.0MVA induction motor with drive system and 1.5MW doubly-fed induction generator, was built and tested in Go-Chang Test Site of KEPCO for analyzing the dynamic interaction with the interconnected distribution system. The operation of hardware simulator was verified through comparative analysis between experimental results and simulation results obtained by simulation model with PSCAD/EMTDC. The developed hardware simulator and simulation model could be effectively used for analyzing the dynamic interaction, which has various phenomena depending on the wind variation and the network state of interconnected power system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.230-236
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• 2014

Superconducting fault current limiter (SFCL) has been expected as one of more effective solutions for decreasing fault current instantaneously and various types of SFCLs have been developed to apply into real power system. Recently, the application of the SFCL in a power distribution system has been reported to be contributed to the suppression of the voltage sag as well as the limitation of the fault current. However, the suppressing effect of voltage sag by the SFCL depends on component of its impedance and its application location in a power distribution system considering the recloser-recloser coordination. This paper analyzed the voltage sag caused by recloser-recloser coordination in a power distribution system and the suppression of the voltage sag due to the application location of the SFCL in a power distribution system was discussed through the PSCAD/EMTDC simulation.