• 전기의세계
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• v.28 no.10
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• pp.9-16
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• 1979

근래 우리나라의 국민소득이 높아짐에 따라 가전제품의 수요가 늘고, 중화학공업의 발달에 따라 전력수요가 급격히 증가하고 있다. 이에 반하여 석유가는 매년 증가하고 있으므로 기력발전소를 지양하고 대용량의 원자력, 양수발전소, 석탄발전소가 건설되고 있는 경향이 있다. 발전소는 입지조건상 해안 또는 강변에 위치하고 있으며 수요지와는 거리가 멀고 또는 계통의 안전도(Stability), 신뢰도(Reliability)를 높이기 위하여 154KV와 345KV 송전선으로 전계통을 연계하고 있다. 송전선의 전력운송능력을 증대시키기 위하여 복도체 또는 사도체로 하고 있으며 전선도 ACSR에서 TACSR로 하는 나라도 있다. 현재 미국에서는 765KV Canada에서는 735KV 송전선으로 운전되고 있으며 장차 1500KV 송전선도 곧 실용화된다고 한다. 이에 따라 송전선의 지지물인 철탑도 대형화되어가고 높이도 증가하게 되어 이의 제작및 건설비가 막대하게 들게되며 앞으로는 용지확보도 더욱 어렵게 되어 송전선의 회전수를 2 또는 4회선으로 건설하여야 될것이다. 송전선철탑설계는 종래에는 Cremona도식해법에 의하여 설계하였으나 이의 작도및 하중조건이 많아지면 부재의 정확한 설계하중을 산출하는 데는 많은 시간과 노력이 필요하다. 이러한 불편을 헤소하기 위하여 Ritter의 수치해석법(moment 방법)을 이용한 전산화 및 설계이론에 대하여 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2371-2373
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• 1999

This paper deals with the development, reliability, specification and performances of the ACSR inner corrosion detector system. It is designed to run on ACSR automatically and to inspect the corrosion of the line with on-line continuously. And it comprises a sensor a constant current source, a signal processing unit, a RF transmitter and receiver unit. Also separable encircling coil sensor is proposed in order to detect inner corrosion of the overhead ground wires. In conclusion, this detector can realize the nondestructive detecting of an ACSR inner corrosion.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2374-2376
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• 1999

This paper deals with some experimental results of the ACSR inner corrosion detector which is developed in order to measure local corrosion of transmission line. Tested wire is ACSR $97{mm}^2$. Experimental procedures, desirable test results and normalizing method of corrosion grade are reported. It is shown that the detector is possible to inspect the inner corrosion of ACSR, through testing and experimental studying for artificial corroded samples.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1410-1416
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• 2011

A corrosion detecting system for 22.9 kV distribution power line insulation cable, which can travel autonomously along the live line, is proposed. Eddy current test method is employed to detect the corrosion, and the system developed here is capable of detecting internal corrosion of a ACSR-OC. Somewhat details of the electrical and mechanical mechanism of the system and traveling algorithm are introduced. Experimental results applied to the sample cables having artificial corrosion and the operating distribution lines are provided. From the result, we confirmed that the system is useful for detecting internal corrosion of a ACSR, and is expected to be a new non-destructive testing equipment in the area of diagnosis for the distribution power line.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.6
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• pp.43-50
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• 2000

Design and experiments of a nondestructive testing system with a solenoid eddy current sensor to inspect deterioration of ASCR-OC (ACSR Outdoor Cross-linked Polyethylene Insulated Wires) usually used in HV overhead distribution lines in domestic areas in presented in this paper. Through corrosion mechanisms and deterioration results for ACSR-OC conductors are examined, it is shown that corrosion may lead to the reduction of the effective cross section area of conductors is proposed. The measurement system consisting of a constant current source with a RF frequency, a signal processing unit and a motor driver/ controller is designed and implemented. This instrument has such capabilities as detecting the sensor output and estimating diameter change of the testing conductors, continuously. As a result, it was verified that such corrosion detector system with an eddy current sensor can be shown good effectiveness for estimating the serious faults due to deterioration in overhead distribution lines and giving an early warming before severe aged conductor may lead to fail.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.112-117
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• 1999

In case of spectral subtraction for noise robust speech recognition system, this method often makes loss of speech signal. In this study, we propose a method that variation and determination of Gaussian function at semi-continuous HMM(Hidden Markov Model) is made on the basis of SNR criteria function, in which SNR means signal to noise ratio between estimation noise and subtracted signal per frame. For proving effectiveness of this method, we show the estimation error to be related with the magnitude of estimated noise through signal waveform. For this reason, Gaussian function is varied and determined by SNR. When we test recognition rate by computer simulation under the noise environment of driving car over the speed of 80㎞/h, the proposed Gaussian decision method by SNR turns out to get more improved recognition rate compared with the frequency subtracted and non-subtracted cases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.44-48
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• 2003

할로겐 난연재료 및 고분자의 연소시 Dioxine의 문제점이 대두되고 있어 유럽국가를 중심으로 할로겐 난연제 사용을 규제하고 있다. 환경과 인체에 대한 안정성을 고려해서 저 유해 가스화, 저 발연화, 저 부식성, 리사이클링 등을 겸비한 제품의 개발로 관심이 모아지고 있는 실정이다. 본 연구에서는 환경친화적인 금속화합(수산화 알루미늄)을 사용하여 연소시 발생할 수 있는 난연성, 무독성, 소연성 등을 함량별로 확인하고 난연재가 증가할수록 취약한 기계적 물성 보완을 위해 moisture cure crosslikable 기술로 케이블절연 및 자켓 피복층 특성을 증가 시켰다. 그러나 수산화알루미늄 함량이 증가할수록 기계적 물성과 기타 특성도 감소하는 경향을 보이고 있어 최적의 난연제 조성함량이 약 130~150 phr정도에서 우수한 결과를 확인하였다. 또한 moisture cure agent는 전선압출 시 표면에 scorch 및 장기 압출에 영향을 주므로 약 1.5~2phr 범위에서 처방하는 것이 우수하다. 원료투입 후 mixing 공정 중에서는 온도관리가 매우 중요하므로 되도록 믹싱 온도를 $130^{\circ}C$ 이하를 유지해야한다. 온도는 수산화알루미늄의 분산성과 케이블 피복압출 시 표면에도 영향을 주기 때문이다 본 연구는 이런 작업방법을 통해 친환경 가교 난연콤파운드가 비(比) 가교된 제품에 비해 특성이 증가되는 것을 입증할 수 있었다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.1-6
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• 2014

A large amount of acidic waste solution is generated from the practical electrokinetic decontamination equipments for the remediation of soil contaminated with uranium. After filtration of uranium hydroxides formed by adding CaO into the waste solution, the filtrate was recycled in order to reduce the volume of waste solution. However, when the filtrate was used in an electrokinetic equipment, the low permeability of the filtrate from anode cell to cathode cell due to a high concentration of calcium made several problems such as the weakening of a fabric tamis, the corrosion of electric wire and the adhension of metallic oxides to the surface of cathode electrode. To solve these problems, sulfuric acid was added into the filtrate and calcium in the solution was removed as $CaSO_4$ precipitate. A decontamination test using a small electrokinetic equipment for 20 days indicated that Ca-removed waste solution decreased uranium concentration of the waste soil to 0.35 Bq/g, which is a similar to a decontamination result obtained by distilled water.