• 한국전기전자재료학회논문지
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• 제25권2호
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• pp.159-164
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• 2012

In this paper, it tried to develop the core sensor for detection of micro magnetic field in electric wires. The sensor is non contact type and is consisted of ferrite core for low price. To investigate their properties for variations of current, it changed the number of winding and the length of sample core, it examined, to check the live wire situation in built-in wires, electrical characteristics due to difference between electric wires and core sensor. As the results, it verified live wire situation at the number of winding(5,000) and within length of 6[cm]. Also, it obtained magnetic field magnitude decreased inverse proportion ratio to a square about difference between electric wires and core sensor.

• 전기저널
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• 3호통권87호
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• pp.38-43
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• 1984

• 한국환경과학회지
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• 제24권2호
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• pp.237-244
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• 2015

This objectives of research are to figure out combustion characteristics with increasing temperature with petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and sawdust, and to exam heating value and ignition temperature for using refused derived fuels(RDFs). After analyzing TGA/DTG, petrochemical sludge shows a rapid weight reduction by vaporing of inner moisture after $170^{\circ}C$. Gross weight reduction rate, ignition temperature and combustion rates represent 68.6%, $221.9^{\circ}C$ and 54.1%, respectively. In order to assess the validity of the RDFs, the petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and waste sawdust. The materials are mixed with 7:3(petrochemical sludge : organic matters)(wt%), and it analyzes after below 10% of moisture content. The ignition temperatures and combustion rates of the waste electric wire, anthracite coal and waste sawdust are $410.6^{\circ}C$, $596.1^{\circ}C$ and $284.1^{\circ}C$, and 85.6%, 30.7% and 88.8% respectively. In heating values, petrochemical sludge is 3,600 kcal/kg. And the heating values of mixed sludge (adding 30% of the waste electric wire, anthracite coal and waste sawdust) each increase up to 4,600 kcal/kg, 4,100 kcal/kg and 4,300 kcal/kg. It improves the ignition temperatures and combustion rates by mixing petrochemical sludge and organic matters. It is considered that the production of RDFs is sufficiently possible by using of petrochemical sludge by mixing wasted organic matters.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.280-286
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• 2006

As a way to expand electric capacity in conductor with electric power demand, STACIR/AW (Super Thermal-resistant Aluminum-alloy Conductors Aluminum-clad Invar-Reinforced) conductor which has high electric current and heat resistance characteristics have been developed. STACIR/AW power line is mechanical composite wire composed of steel cores for dip control and aluminum conductors for sending electric current. Recently, to ensure stable operation and prediction of wire life span of STACIR/AW conductor, a heat property of STACIR/AW conductor have been investigated. In the present work, a change of essential property with long term-heat exposure of STACIR/AW conductor and its structure material, INVAR wire and Al conductor, have been investigated. INVAR/AW is approximately $3.2\;{\mu}m/m^{\circ}C$. thermal expansion coefficient of INVAR/AW wire increases with time of heat exposure. the thermal expansion coefficient of INVAR/AW is markedly influenced by heat and mechanical treatment. creep rate(0.242) of STACIR/AW $410\;mm^2$ conductor at room temperature is much higher than that(0.022) at $210\;^{\circ}C$ STACIR/AW $410\;mm^2$ conductor has minimum creep rate at operating temperature. To lower creep rate with increase temperature is more unique characteristics in STACIR/AW. It is expected that STACIR/AW turned its tension to INVAR/AW at the transition temperature. at room temperature, the tension apportionment of INVAR/AW in STACIR/AW is about $50\;\%$. but whole tension of STACIR/AW is placed on the INVAR/AW alone of core metal above transition temperature.

• 수산해양기술연구
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• 제33권1호
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• pp.27-37
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• 1997

The aim of the present study is to investigate experimentally the mechanism of an exploding wire in water and also to observe the bubble motion induced by an exploding wire. The experiment of an exploding wire is carried out in a water tank. As a metallic wire, a tungsten wire of 0.2mm in diameter and 10mm in length is employed. The electric energy of 50-300J is fed to the wire from a capacitor of 100$\mu$F charged up to 1-2.5kV. The explosion is recorded by a CCD camera with the resolution of 1$\mu$sec. The explosion process of metallic wire is divided into three phases. Phase 1 : As the voltage is applied to the wire, the temperature increases due to Joule heating and the wire emits light. Phase 2 : Then the wire melts and the cylindrical plasma is formed between the electrodes. Up to this stage, strong light emission is observed. Phase 3 : The light emission goes out and a vapor bubble begins to grow spherically. The radius of a bubble oscillates in time, but the amplitude of oscillation diminishes in several cycles.

• 한국전기전자재료학회논문지
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• 제24권6호
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• pp.497-503
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• 2011

Currently in Korea, the simple catenary type overhead contact line system is being applied to both conventional lines and high speed lines of electric railway, and circulation current flowing into the catenary system frequently bring undesirable consequences. Namely, the connector wire has many problems according to a flow of excessive circulation current and arc current on catenary when an electric train runs at high speed. This paper presents the development and application of a real-time data acquisition system designed to measure the electrical characteristics of an overhead catenary system in electric railways. The developed system is capable of storing data of a 25 kV power source in a live wire state through a telemetry environment. The field test results show that the proposed technique and the developed system can be practically applied to measure characteristics of current of an overhead catenary system.

• 한국산학기술학회논문지
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• 제11권4호
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• pp.1342-1347
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• 2010

무선 센서 네트워크의 다양한 연구 분야 중에서 철조망에서의 표적의 침입 탐지 및 식별에 관한 연구는 산업시설, 보안지역, 교도소, 군사지역, 공항 등 다양한 분야에서 사용된다. 현재 철조망 감시는 대부분 유선 센서 노드를 통한 유선 센서 네트워크 환경에서 이루어지고 있다. 기존의 유선 센서 네트워크는 100bps 이상의 높은 데이터 전송률을 통해 수신되는 높은 샘플링 신호를 이용하여 고속 푸리에 변환에 의한 신호의 주파수 분석 기법을 사용해 왔다. 하지만, 유선 센서 네트워크의 높은 데이터 전송률과 비교하여 무선 센서 네트워크의 센서 노드는 유선 센서 네트워크에 비해 매우 낮은 데이터 전송률을 가진다. 따라서 무선 센서 네트워크에서 수신되는 신호의 샘플링이 매우 낮고, 유선 센서 네트워크에서 사용된 고속 푸리에 변환에 의한 신호의 주파수 분석에 따른 주파수별 특징 추출을 할 수 없다. 따라서 본 논문에서는 철조망 감시를 위한 높은 데이터 전송률을 보장하는 유선 센서 네트워크에 비해 제한된 통신자원과 센서 노드의 낮은 데이터 전송률로 인해 수신되는 한정적인 신호의 정보를 이용한 무선 센서 네트워크에서 철조망의 표적 침입 탐지 및 식별을 위한 특징 추출 알고리즘을 제안한다.

• 한국정밀공학회지
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• 제22권4호
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• pp.27-36
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• 2005

Some studies have shown that unstable factors are inherent in WEDM process, causing the instability of the discharging pulse to reach about 40∼60％ in normal machining. Transient stability is an important subject in WEDM process since there is a close relationship between stability and machining performance, such as the characteristics of a machined surface, machining speed and problem of instability like wire rupture phenomenon. Among the many machining parameters affecting WEDM machining state, three specific parameters (Vr, Ip, off time ) are major controllable variables that can be applied in transient stability control. And, this research investigates the implementation and analysis of real-time micro control of the discharging stability of WEDM (Wire Electric Discharge Machining) process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.272-273
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• 2015

This paper analyze scenario of feeder wire fault that occurs in the AC feeding system considering train position. The fault location of AC feeding system is calculated by measuring impedance. However, in this way, estimation error can be occurred because of tie connection, boosting current, etc. Therefore, it's hard to find fault location, so that it is required to detailed circuit analysis according to fault location. We analyze the short circuit impedance values with respect to feeder wire fault according to a train position. In this paper, PSCAD is used for modeling and analysis of AC railway feeding system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2251-2252
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• 1999

In this paper, the effect of magnetic field was measured on NOx removal characteristics for wire-plate plasma reactor with magnetic field applied to electric field vertically. NOx from simulated diesel engine flue gas are decomposed by the corona discharge of DC, AC and Pulsed voltages in wire-plate reactor. Consumption power increased with increasing discharge voltage. When magnetic field was applied to electric field vertically, consumption power decreased. NOx removal rate and arc transition voltage of plasma reactor with magnetic field were higher than those of plasma reactor without magnetic field.