• Progress in Superconductivity and Cryogenics
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• v.11 no.3
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• pp.46-49
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• 2009

A 3-phase 100m long, 22.9kV class HTS power transmission cable system was developed by Korea Electrotechnology Research Institute (KERI) and LS cable Ltd. those are participated in the 21st Century Frontier project R&D Program of Korea. It is important to test the DC critical current related with its power capacity before applying to the real power grid. In 1995, several international standards organizations including International Electrotechnical Commission (IEC), decided to unify the use of statistical terms related with 'accuracy' or 'precision' in their standards. It was decided to use the word 'uncertainty' for all quantitative (associated with a number) statistical expressions. In this paper, we measured DC critical current of 22.9kV/50MVA superconducting power cable with several voltage tap and analyzed the uncertainty with these results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.90-96
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• 2014

The electrical resistivity of concrete can be related to two processes involved in corrosion of reinforcement: initiation (chloride penetration) and propagation (corrosion rate). The resisistivity of concrete structure exposed to chloride indicates the risk of early corrosion damage, because a low resistivity is related to rapid chloride penetration and to high corrosion rate. Concrete resistivity is a geometry-independent material property that describes the electrical resistance, which is the ratio between applied voltage and resulting current in a unit cell. In previous study, it was realized that the resistivity of concrete depended on the moisture content in the concrete, microstructural properties, and environmental attack such as carbonation. The current is carried by ions dissolved in the pore liquid. While some data exist on the relationship between moisture content on electrical resistivity of concrete, very little research has been conducted to evaluate the effect of chloride on the conduction of electricity through concrete. The purpose of this study is to examine and quantify the effect of chloride content on surface electrical resistivity measurement of concrete. It was obvious that chloride content had influenced the resistivity of concrete and the relationship showed a linear function. That is, concrete with chloride ions had a comparatively lower resistivity. Decreasing rate of resistivity of concrete was clear at early time, however, after 50 days resistivity was constant irrespective of chloride concentration. Conclusively, this paper suggested the quantitive solution to depict the electrical resistivity of concrete with chloride content.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.291-296
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• 2009

"The Act on Ubiquitous City Construction and etc." stipulates the regulations on the planning, construction and management of the u-City. As its national-level law system is about to take its effects, future new city developments are expected to have its legal basis to be built to meet u-City requirements. Also, it is anticipated that such needs would require much more planning techniques and strategies. In reaction to those upcoming needs, this study is to search for new IT infrastructure construction process of the u-City in reality. It is also to supply with the each step framework to execute the u-City projects in more structuralize and systemize manner. Therefore, with the u-City IT infra construction guide line v1.0, purpose of the establishment of comprehensive IT infrastructure construction process.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.90-95
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• 2015

This paper proposes the new adaptive gain control monitoring sensor for the marine IT system. The marine IT system sensors make it possible to conduct search missions, record climate changes, provide pollution control, study marine life, conduct survey missions, tactical surveillance, and predict natural disturbances in the ocean. In this paper, the adaptive gain control circuit which changes its parameters according to the ambient noise situation for obtaining the precise location information of marine IT system sensor is developed and analyzed. The performance characteristics for ensuring the precise location information of marine system sensor is presented and analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring of the marine system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2328-2334
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• 2009

Through the development of phasor measurement units (PMU), various aspects of power system dynamic behavior could be monitored and diagnosed. Monitoring dynamic voltage stability becomes one of achievements we can obtain from PMUs. It is very important to select the method appropriate to the KEPCO system since there are many voltage stability indices. In the paper, we propose an advanced WAVI (Wide Area Voltage Stability) for monitoring dynamic voltage stability. It reflects the PMU installation plan of KEPCO, thus it is suitable for KEPCO system specially. The salient features of the proposed index are; i) it uses only PMU measurements without coupling with EMS data. ii) it is computationally unburden so that it can be applied to real-time situation. The proposed index is applied to the KEPCO test system and the result shows that it successfully predicts voltage instability through the comparative studies.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2273-2274
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• 2008

It respects the high speed of the Bitter expense decoder from the present paper ACS (Add Compare Select) block structures of new method it proposed. It became component anger of existing and it substituted it added all input price it predicted with the method which reduces the operation which is unnecessary it chose respectively ACS unit and a union logical operation circuit and the result after operation one in advance.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.721-722
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• 2006

Industrialization and technique consequently in quick development the motor field small size and light weight, high efficiency and highly energy density in necessity. The permanent magnet motor small size and the research regarding the research of the torque and efficiency is coming to be active. From this paper the research regarding the quality permanent magnet motor and analysis and it was developed recently the NdFeB anisotropic bond magnet which is a high magnetic force material use, from the hazard which accomplishes power density it is high permanent magnet motor of small size and light weight it researched. The Finite Element Method it led and motor optimization. Also the experiment and analysis permanent magnet motor it is improved the motor and result it led and different it compared.

• Journal of IKEEE
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• v.27 no.1
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• pp.103-108
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• 2023

This research was carried out experiments with changing processes and design parameters to optimally design a SiC-based 1200V power MOSFET, and then, essential electrical characteristics were derived. In order to secure the excellence of the trench gate type SiC power MOSFET device to be designed, electrical characteristics were derived by designing it under conditions such as planner gate SiC power MOSFET, and it was compared with the trench gate type SiC power MOSFET device. As a result of the comparative analysis, the on-resistance while maintaining the yield voltage was 1,840mΩ, for planner gate power MOSFET and to 40mΩ for trench gate power MOSFET, respectively, indicating characteristics more than 40 times better. It was judged that excellent results were derived because the temperature resistance directly affects energy efficiency. It is predicted that the devices optimized through this experiment can sufficiently replace the IGBT devices generally used in 1200V class, and that since the SiC devices are wide band gap devices, they will be widely used to apply semiconductors for vehicles using devices with excellent thermal characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.661-664
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• 2007

일본의 상호접속은 전기통신사업법에 법적인 근거를 두고 설비를 보유한 특정 전기통신사업자가 설비를 보유한 다른 전기통신사업자로부터 상호접속의 요청이 있는 경우 다음의 특별한 사유를 제외하고는 상호접속을 이행토록 강제하고 있다. 특히, 1종 지정전기통신설비를 보유한 사업자(현재 NTT 동일본, NTT서일본이 각각 지정)는 고정계의 필수설비를 보유한 시장지배적사업자로, 필수설비 접근의 제한 및 지배력남용을 방지하기 위하여 강한 규제를 받고 있다. 특히, 상호접속부문에서는 LRIC에 의한 접속료 규제를 받는 유일한 사업자로 NIT가 지정되어 있는 상황이다. 반면, 2종 지정전기통신사업자(이동계 지배적사업자)와 기타의 전기통신사업자는 이러한 접속료 규제를 받기는 하지만 1종지정전기통신사업장와 같은 접속약관인가가 아닌 신고제를 적용받고 있다. 다만, 이용자들의 end-to-end 서비스의 보장을 위해 상호접속을 실시도록 하고 있다. 이에 본고는 현행 일본의 상호접속관련 규정 및 접속료 산정 guideline인 접속료 규칙을 살펴보고자 한다.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.95-98
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• 2007

소비자들의 미래주택에 대한 요구 중 대부분은 좀 더 편리함과 안전함을 제공받고자 하는 것이다. 근래에 퓨전개념으로 시작한 전력IT 관련 기술개발을 시작으로 다양한 홈 디지털 서비스 제공방안이 제시되고 있다. 본 논문에서는 주택 내 전기안전 소비자 U&A 및 Needs를 조사하고, 전기 포탈 서비스(H-SCP) 컨셉에 대한 소비자 수용도와 Needs를 파악하였다. 이 소비자의 조사결과는 앞으로 전기 포탈 서비스의 연구 진행 방향에 중요한 기초자료가 될 것으로 기대된다.