• 대한전기학회논문지:전력기술부문A
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• 제55권8호
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• pp.334-340
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• 2006

Copper is widely used in electric wire, cable, conductor in electric devices. As the demand for electric power is increasing rapidly, electric power devices are getting amazingly bigger and complicated. The using of light-weight conductor can reduce the size and making cost of the electric devices. In high-frequency application, Electric current in a conductor tends to shift to the surface of the conductor, resulting in an uneven current distribution in the inner conductor. In the extreme case the current may essentially concentrate in the 'skin' of the inner conductor as a surface current. In high frequency application, therefore, inner area of copper conductor may replace with aluminum conductor, which reduces the weight of conductor. This paper describes the manufacture and evaluation of composite conductors made of copper and aluminum. The optimum extruding ratio was 16 at $300^{\circ}C$. The electrical resistance of manufactured composite bus bar was $57{\mu}{\Omega}$ at DC and $49.5{\mu}\{Omega}$ at 300Hz.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.621-622
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• 2005

Copper is widely used in electric wire, cable, conductor in electric devices. As the demand for electric power is increasing rapidly, electric power devices are getting amazingly bigger and complicated. The using of light-weight conductor can reduce the size and making cost of the electric devices. In high-frequency application, Electric current the current in a conductor tends to shift to the surface of the conductor, resulting in an uneven current distribution in the inner conductor. In the extreme case the current may essentially concentrate in the "skin" of the inner conductor as a surface current. In high frequency application, therefore, inner area of copper conductor may replace with aluminum conductor, which reduces the weight of conductor. This paper describes the manufacture and evaluation of composite conductors made of copper and aluminum.

• Journal of electromagnetic engineering and science
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• 제4권1호
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• pp.43-49
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• 2004

A low-frequency coaxial reflectometer(LCR) with a thin-wire inner conductor is designed and constructed to measure nondestructively the absorbing performance of electromagnetic absorbers in the frequency range of 10 MHz to 200 MHz. The LCR consists of a square coaxial transmission line and a network analyzer with a time-domain measurement capability. Inherent characteristics of a square coaxial line with a thin-wire inner conductor which deteriorate the impedance matching of the input port of the LCR are addressed. And the characteristics are improved by employing a multiwire inner conductor. Measured and calculated reflection losses of a flat ferrite tile absorber are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1935-1937
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• 1996

This paper deals with ACSR(Aluminum Conductor Steel Reinforced) inner corrosion detection using a detector which automatically runs on an ACSR transmission line and inspects the inner corrosion of the conductor by utilization of the nondestructive eddy current test. And the relationship between the corrosion grades and the tensile strength can be estimated by means of this test. According to corrosion appearance and development of ACSR, the impedance change of the eddy current coils is theoretically verified. And then specifications And performances of the detector are described. Experimental procedures and desirable test results are reported. In conclusion, this detector can realize the nondestructive detecting of an ACSR inner corrosion. Upgrading the maintenance effciency and improving the reliability of transmission line would be expected by this nondestructive test method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
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• pp.35-39
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• 2002

아몰퍼스 자성와이어를 센서헤드로 이용한 금속 구조체의 미세결함 검사에 대해 검토하였다. 측정 방법은 스파이럴 코일의 균일 자장범위에 직선 갭을 가진 동판을 놓고 갭 주위를 관통하는 자속량의 차이를 센서헤드의 유기전압으로 측정하는 것이다. 이 결과 두께 1mm, 갭폭 0.5mm의 동판에 대해 100kHz~600kHz의 주라수 범위에 있어서 갭 근방에서 약 2.5mV의 전압차가 얻어져 결함의 유무를 확인할 수 있었다.

• 한국인터넷방송통신학회논문지
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• 제13권4호
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• pp.201-208
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• 2013

본 논문은 한쪽 면이 열린 동축 공동 공진기의 경험적 설계 방법에 대한 연구이다. 공진기의 내부 도체 반경과 공진기의 내경 그리고 길이를 이용하여 설계한다. 그러나 기본 동축 선로 이론을 적용하면 내부 도체 반경과 공진기의 내경 값에 관계없이, 길이 변화에 의해서만 공진 주파수와 Q값의 특성이 달라지는 것을 알 수 있다. 따라서 내부 도체 반경과 공진기 내경 그리고 길이의 영향을 알아내고, 경험적 설계를 통해 이론값과 설계값의 오차를 줄여 최적화된 공진기 설계 방법을 제안한다. 모의실험 결과를 바탕으로 공진기의 내경은 14 mm, 내부 도체 반경은 각각 2 mm, 5 mm, 10 mm 그리고, 공진기의 길이는 8.5 mm로 제작하였다. 제작된 공진기의 공진 주파수는 6.1, 5.7, 6.5 GHz로 측정되었다. 모의실험과 제작된 공진기를 측정한 결과에 의하면, 공진기의 길이가 10 mm이하일 때는 기본 동축 전송 이론을 직접 적용하고, 10 mm이상 일 때는 계산된 공진 주파수에 0.5 GHz보정인자 값을 더함으로써 비교적 오차가 작은 한쪽 면이 열린 동축 공동 공진기를 설계 할 수 있음을 알 수 있었다.

• 전기학회논문지
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• 제56권6호
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• pp.1035-1038
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• 2007

We designed and manufactured a 1.8T high temperature superconducting(HTS) insert coil for a NMR magnet operated at 4.2 K. Suitable HTS superconductor and HTS coil were carefully designed and developed. We have selected multi-filamentary Bi2223 conductor fabricated by American Superconductor Corporation(AMSC). The selected conductor consists of Bi2223 filaments of 55, silver stabilizer and stainless steel reinforcement tapes. Therefore, it shows good hoop strength as well as compression tolerance. The conductor has a tape cross-section of 0.31mm x 4.8mm. the Bi2223 conductor shows large anisotropy of critical current. The critical current of conductor in magnetic field parallel to the flat surface are much higher than that in magnetic field perpendicular. The HTS coil has an inner diameter of 78 mm, an outer diameter of 127 mm and a coil length of 600 mm. In this paper, the detailed design, fabrication and test results on the HTS insert coil are presented.

• 한국통신학회논문지
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• 제21권6호
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• pp.1576-1586
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• 1996

The subject of this paper is the analysis of a Wire-TEM cell(W-TEM cell) which has an inner wire array rather than a metallic septum;its basic structure is similiar to a NBS TEM cell. To verify improved performances of this W-TEM cell as a standard EM field generator, well-known quasi-static approximations are employed and their resultant ingegral equations are numerically analyzed by moment method. Although the electric field strength of a W-TEM cell is 1.4 dB lower than tht of a NBS TEM cell, the uniformity of EM field patterns in a W-TEM cell is improved. It is also shown that the EM field distortions resulting from loading by the conditing objects under test(loading effects), are decreased considerably. This paper also deals with the investigations about relationship between the EM field distributions and the number of wire composing the inner conductor. Finally, the experimental analysis is performed on the practical model which is built on the basis of the design variables brought out by the theoretical andnumerical analysis.

• 조명전기설비학회논문지
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• 제12권1호
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• pp.12-19
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• 1998

본 논문에서는 와전류센서를 장착하고 전선위를 자동으로 주행하도록 설계된 부식 검출장치를 이용하여 ACSR의 내부부식 검출에 대해서 다룬다. 또한 내부부식의 검출은 비파괴검사로 행해진다. 독특한 ACSR의 구조에 의한 부식현상을 와전류센서를 이용하여 검출하는 경우, 부식은 센서의 임피던스변화로 검출되고 이 현상을 이론적으로 증명한다. 또한 설계된 부식검출장치의 사양과 성능 그리고 실험방법에 대해 논하고, 현장에 적용가능한 실험결과를 얻었다. 이 부식검출장치는 ACSR의 내부부식을 비파괴로 검출할 수 있고 현실적이라는 결론을 얻었다. 피시험체인 도체의 피복여부에 관계없이 이장치는 이용가능하고, 이 장치의 실용화에 의해 선로의 유지보수의 효율을 증대시키고 선로의 향상이 기대된다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.269-271
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• 2003

A typical HTS power transmission cable has multi-layer conductor structure to increase the current capacity. The tapes of the innermost layer are wound on a round former, and adjacent tapes of another layer are separated by a thin insulating film. In steady state, the total current flows in the conductor layer, and consequently there is magnetic field between the inner and outer layer. This paper describes a magnetic field amplitude around the conductor layer and the HTS tape by a transport current. Also, this paper will help for future cable conductor prototypes.