• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권10호
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• pp.554-559
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• 2002

The at loss is an important issue in the design of superconducting cables and transformers. In these devices the Bi-2222 tapes are usually placed face-to-face. In such arrangements ac loss is influenced by adjacent tapes. The effect is investigated by measuring the magnetization loss in the stacked conductor, which consists of various numbers of Bi-2223 tapes. For the single tape the magnetization loss in perpendicular field is larger than that in parallel field by about a factor 10. This agrees well with the prediction for hysteresis loss in slab and strip models. For the stacked conductor in perpendicular field the magnetization loss at low fields is greatly decreased, compared to the loss of the single tape. However the loss at high fields is nearly unaffected. This behavior is well described by the slab model.

• 한국전기전자재료학회논문지
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• 제18권6호
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• pp.532-537
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• 2005

In order to develop a tunable resonator which can be easily operated by DC bias and applied for microwave tunable filters and devices using ferroelectric thin or thick films, the non conductor backed-and conductor backed- coplanar stripline resonators have been designed and analyzed. They have been designed to be operated at 25 GHz which involve coplanar stripline input and output ports. The resonators have been simulated and analyzed using Ansoft HFSS. The research has been focused on the Quality factor of the coplanar stripline resonator. The conductor Q, box Q, and radiation Q of the resonators have been analyzed and calculated according to the substrate thickness & conductor width of the resonators. From these parameters, the loss factors of the coplanar stripline resonator have been investigated. The conducting Q of the coplanar stripline resonator has no relation with the thickness of dielectric substrate and increases as the conductor width increases. The box Q has no much relation with the thickness of substrate and the conductor width, which is above 2000. The radiation loss increases as the thickness of substrate and the conductor width increase. To decrease the radiation loss of the coplanar stripline resonator, a conductor backed coplanar stripline resonator has been proposed which has the unloaded Q of 170.

• 한국초전도ㆍ저온공학회논문지
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• 제7권1호
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• pp.47-50
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• 2005

The AC loss is an important issue in the design of the high temperature superconductor (HTS) power cables, which consist of a number of lli 2223 tapes wound on a former. In the cables, the tapes have different critical currents intrinsically. And they are electrically connected to each other and current leads. These make loss measurements considerably complex, especially for short samples of laboratory size. In this work we have prepared a multi-tape conductor composed of Bi-2223 tapes. The at losses of the conductor have experimentally investigated. The loss tests indicate that the effect of tapes critical currents on AC loss measurement in the multi tape conductor is negligible only if currents in the tapes flow uniformly Moreover, the measured tosses of the conductor are in good agreement with the sum of the transport losses in the tapes. However, in the case of non-uniform current distributions, the measured AC losses considerably depend on the current distribution parameter of the positioning of a voltage lead. Thus special cautions should be needed for the measurement of the true AC losses in the short power cable samples.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1152-1158
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• 2005

New conductor is developed by using high strength nonmagnetic steel(NM) wire as the core of overhead conductor. This conductor is called ACNR overhead conductor(Aluminum Conductor Nonmagnetic Steel Reinforced). Formed by the combination of aluminum alloy wire and high strength nonmagnetic steel wire, it has about the same weight and diameter as conventional ACSR overhead conductor. To enhance properties beneficial in an electrical and mechanical conductor during the process of high strength nonmagnetic steel wire, we made a large number of improvements and modifications in the working process, aluminum cladded method, and other process. ACNR overhead conductor, we successfully developed, has mechanical and electrical properties as good as or even better than conventional galvanized wire. Microstructure of raw material M wire was austenite and then deformed martensite after drawing process. Strength at room temperature is about $180kgf/mm^2\~200kgf/mm^2$. NM wire developed as core of overhead conductor shows heat resistant characteristics higher than that of HC wire used as core of commercial ACSR overhead conductor, Strength loss was not occur at heat resistant test below $600^{\circ}C$. Fatigue strength of vibration fatigue is about $32kgf/mm^2\~35kgf/mm^2$ and that of tension-tension fatigue is $90kgf/mm^2\~120kgf/mm^2$ which is $50\~65\%$ of tensile strength.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.46-49
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• 2002

The ac loss is an important issue in the design of superconducting cables and transformers. In these devices the Bi-2223 tapes are usually placed face-to-face In such arrangements ac loss is influenced by adjacent tapes. The effect is investigated by measuring the magnetization loss in the stacked conductor, which consists of various numbers of Bi-2223 tapes. For the stacked conductor in perpendicular field the magnetization loss at low fields is greatly decreased, compared to the loss of the single tape. The loss at high fields is unaffected. This behavior is well described by the slab model.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.40-44
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• 2023

For high-temperature superconducting power applications that need large current capacity, a large current conductor manufactured using multiple superconducting tape is required. Conductors being studied for large currents capacity such as CORC, TSTC, and RACC have advantages and disadvantages, and in order to use these conductors in coil form and apply them to AC power devices, research on magnetization loss occurring in superconductors due to external magnetic fields is essential. To accurately measure magnetization loss in a conductor that is twisted by stacking straight conductors like TSTC, the correlation between the measuring system and the shape of the sample must be clearly known to accurately measure the loss. In this paper, we will confirm the difference in magnetization loss measurement values according to the correlation between the length of the pickup coil and the twist pitch of the sample in CORC and TSTC shapes, and review considerations for accurate magnetization loss measurement from the results.

• 조명전기설비학회논문지
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• 제21권8호
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• pp.113-120
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• 2007

본 논문은 TN-C-S계통에서 중성선 겸용 보호도체(PEN도체)의 단선고장시 감전의 위험성 및 보호대책에 관한 것으로 PEN도체의 단선고장시 노출도전성 부분의 접촉전압을 줄이기 위하여 전원측 접지저항과 수용가 추가접지 저항에 따른 PEN도체 단선시 노출도전성 부분에 나타나는 접촉전압을 실험적으로 조사하였다. 그 결과 TN-C-S 계통으로 공급되는 설비에 대하여 등전위본딩은 중요한 요건이다. 수용가의 인입구에 추가접지를 하는 것은 PEN 도체의 단선시 노출도전성 부분에 나타나는 접촉전압을 저감시키는 방법 중의 하나이다. 접촉전압을 안전전압 50[V]이하로 제한하는데 필요한 추가접지의 접지저항은 부하용량과 고장회로정수에 의하여 정해진다. 또한 부족전압계전기는 TN-C-S계통에서 PEN도체의 단선고장을 검출할 수 있는 적절한 해결방안이 될 수 있다.

• 한국초전도ㆍ저온공학회논문지
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• 제10권3호
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• pp.23-26
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• 2008

Constructions of coated conductor which is differently from Bi-2223 is comprised multiple coatings on a base material or substrate and designed to achieve the highest degree of alignment possibility of the atoms in the superconductor material. In this study, we are measured and analyzed degradations of critical current according to diameter. In addition to study the effects of bending strain, we observed the AC loss of coated conductor and carried out analytical study for relation between Ic degradation and AC loss as well. The measurement of AC loss and numerical calculation was carried out based on Norris theory to compare with experimental results. The relationship between critical current and AC loss of HTS tapes with partial deformation by mechanical stress was studied. These results will amount the most important basis data in the of HTS cable, magnet, etc that winding work is required.

• 한국전자파학회논문지
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• 제11권8호
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• pp.1305-1312
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• 2000

본 논문에서는 Finitely Backed Conductor(FBC) CPW(Coplanar Waveguides) 구조를 이용한 대역 통과 필터를 제안한다. 특히, 마이크로 스트립 전송 선로와 비교하여 CPW구조의 단점인 적은 결합량 문제를 해결하기 위한 방법으로 구조적 변화를 통한 특성 향상을 소개한다. 본 논문에서는 FBC 구조를 이용하여 협대역 대역 통과 필터를 제안하였으며, 측정 결과를 통해 삽입 손실의 향상 효과를 확인할 수 있다. Finitely backed conductor(FBC)를 이용한 CPW 대역 통과 필터를 설계하기 위해 FEM 방식을 이용한 HP사의 HFSS 소프트웨어를 사용하였다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.260-262
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• 2003

AC loss is an important issue in the design of high-T$_{c}$, superconducting power cables which consist of a number of Bi-2223 tapes wound on a cylindrical former. In this paper, the ac loss characteristics in the 3-conductor have investigated experimentally. The loss test results indicate that the ac loss is not related to the arrangement of Bi-2223 tapes, contact position and applied frequency. The measured losses in face-to-face arrangement are larger than those in edge-to-edge arrangement. The measured losses in the 3-conductor also agree well with the sum of the transport losses measured in each Bi-2223 tape.e.