• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.23-28
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• 1999

The manufactured pulsed power system with 500kA current is described in this paper. The capacitor bank, control cabinent, dec charging unit, closing switch and dumping box, cable system etc. employed with the system components are described. Especially the development of the inverse pinch switch controlled by gas puffing enabled the generation of the very high voltage and current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.216-217
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• 2007

In this paper we investigated the volume resistivity and AC conduction current according to the temperature and voltage. As a result, the volume resistivity comes to be small according to the measurement temperature and voltage. AC conduction current of the heat treatment specimen is increased because of the decrease of insulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.187-193
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• 2018

There has been a gradual increase in the demand for the electric power in Korea. In order to meet the demand, power station should have technical functions with increased effectiveness. When accident happens in electric machinery at power stations, huge amount of economic losses and mulfunction of equipments occur. One of the accidents is a deteriorated cables operating power stations. In order to prevent cable accident in advance, we should monitor the insulation status of the cable. Cable accidents are resulting from the junctions. We have developed and installed a device in order to identify the status of junction part of power cable at Korea Western Power Co., Ltd.. We performed an accurate diagnosis for the stable utilization of junctions where the accidents occurs most frequently, and to increase the reliability. In this paper, we present the concepts of our device and the method of monitoring diagnosis for the stable use of junctions at cables predicting the life time of cables by analyzing the data obtained by the device. We also present the hardware aspect of the device we have developed.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.253-255
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• 2002

The necessity of compact high temperature super conducting cables is more keenly felt in densely populated metropolitan areas. As the compact high temperature superconducting cables that can be installed in ducts and tunnels can reduce construction cost and make the use of underground space more effective, the effect of introducing it to power system will be huge. For this study, Seoul, Korea is selected as a review model, the loads are estimated by scenario based on a survey and analysis of 345kV and 154kV power supply networks in this area. Based on this, the following items on urban transmission system are examined. (1) A method of constructing a model system to introduce high temperature superconducting cables to metropolitan areas is presented. (2) A case study through the analysis of power demand is conducted, and the amount of high temperature superconducting cable to be introduced by scenario is examined. (3) The economy involved in expanding existing cables and introducing high temperature superconducting cables(ducts or tunnels) following load increase in urban areas is examined and compared. (4) The maximum external diameter of HTS cable to accommodate exiting ducts based on the design standards for current cable ducts is calculated. (5) The voltage level that can be accommodated by existing ducts is examined.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.185-191
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• 1992

In this paper, it is attempted to distinguish the charged particles and to judge the polarity by the use of Thermally Stimulated Current(TSC) and Temperature Gradient Thermally Stimulated Surface Potential Measurement(TG-TSSP)with experimental insulation material XLPE-EVA for power cables which is made by blending cross-linked polyethylene(XLPE) and ethylene-vinylacetate copolymer(EVA). In addition, it is performed to investigate the effect of EVA blending. From the experimental results, it is known that for the case of XLPE-EVA blended experimental material, the generation of space charged electric field is not obtained in the high temperature region due to the obatruction of the injection of trapping carrier by the electron and the positive hole.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.143-146
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• 1994

In older to investigate the properties of electric conduction in low density polyethylene(LDPE) for power cable, the thickness of specimen was the 30, 100($\mu\textrm{m}$) of LDPE. The experimental condition for conductive properties was measured until the breakdown occurs at temperature ranges from 30 to 110[$^{\circ}C$] and in the electric field of 1 to 5 ${\times}$10$^2$[Mv/m]. As for increase of temperature, the current density of LDPE was increased with constant ratio in low field, but changes with exponential function in high field. The tunnel current of pre-breakdown region is shifted toward low field as much as thermal excitation energy.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.410-412
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• 2011

Magnetic cables that can deliver high frequency AC electric power safely for flammable or sensitive workplaces preventing from arcs and electric shocks are firstly proposed in this paper. To deliver the power for a long distance, several new magnetic cable structures which drastically reduce the parallel leakage flux by appropriate magnetic shield between the magnetic cables are suggested; hence, the output power can be improved more than ten times. The proposed magnetic cables are fully analyzed and verified by simulations and experiments with good agreement. The output power and efficiency for a prototype magnetic cable of 1.5m long and 1 cm gap between parallel cores were measured as 154W and 67 %, where the source current and frequency were 10 A and 20 kHz, respectively.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1367-1370
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• 2002

This paper introduces a new web based method to remotely upgrade firmwares of Cable Modems (CM) which are integral part in providing high-speed Internet access through Hybrid Fiber Coaxial (HFC) networks. Also, it discusses various practical problems arising in the upgrading process. Traditional upgrade has been performed by modifying the CM configuration fie. This paper shows a new web based CM firmware upgrade method using SNMP and MIB which greatly reduces upgrading time, cost and man-hour than traditional firmware upgrade methods. This method has been shown to be very efficient and practical. This method will make significant impact especially because tens of million cable modems are currently waiting to be upgraded soon to the next version from the current version.

• Journal of Power Electronics
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• v.17 no.1
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• pp.242-252
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• 2017

This paper deals with the blocking of DC-fault current during DC cable short-circuit conditions in HVDC (High-Voltage DC) transmission systems utilizing Modular Multilevel Converters (MMCs), where a new SubModule (SM) topology circuit for the MMC is proposed. In this SM circuit, an additional Insulated-Gate Bipolar Translator (IGBT) is required to be connected at the output terminal of a conventional SM with a half-bridge structure, hereafter referred to as HBSM, where the anti-parallel diodes of additional IGBTs are used to block current from the grid to the DC-link side. Compared with the existing MMCs based on full-bridge (FB) SMs, the hybrid topologies of HBSM and FBSM, and the clamp-double SMs, the proposed topology offers a lower cost and lower power loss while the fault current blocking capability in the DC short-circuit conditions is still provided. The effectiveness of the proposed topology has been validated by simulation results obtained from a 300-kV 300-MW HVDC transmission system and experimental results from a down-scaled HVDC system in the laboratory.

• International Journal of Contents
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• v.9 no.1
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• pp.38-41
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• 2013

The clamp meter maintains electric safety as a non-invasive method while measuring the absolute value of tube current with it has been recently developed for an X-ray high-tension cable. Especially this can show high accuracy at short X-ray exposure time. Considering such a condition, this study is to evaluate the feasibility of a clamp meter in measuring X-ray tube current by taking the measurements and comparing with those of the Dynalyzer III which has been considered as a standard measuring device. From measuring the tube current accuracy depending on changes in tube voltage and exposure time, the clamp meter showed higher accuracy rate which was -1.3~4.2% difference. Thus clamp meter can be used for clinical radiologists who are not familiar electric circuit to manage X-ray devices easily and correctly in the future.