• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.233-237
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• 1991

In the study, samples were made on the electrode in internal glass bell jar by the radio frequency discharge polymerization. The polymerization rate of samples was observed as a function of r.f. discharge power. The characteristics of polymers obtained from TMDSO and HMDSO were analyzed by FT-IR and TGA, and their electrical properties were examined on insulation resistivity, breakdown voltage, dielectric constant, and tan ${\delta}$. (1) There was no difference between PPTMDSO and PPHMDSO in a polymerization rate and thermal and electrical properties. (2) The growing rates of thin film with discharge powers were from $0.42{\mu}/h$ to $1.2{\mu}m/h$. (3) According to IR spectra analysis, discharge power did not effect polymer structure due to polyermization mechanism and effected only polymerization rate. (4) PPTMDSO and PPHMDSO were thermally resistive polymers which did not decompose to $300^{\circ}C$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1536-1537
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• 2011

The high-voltage circuit breaker plays an important role in the electrical system because there has been a need for suitable switching devices capable of initiating and interrupting the flow of the electric fault current. It continues as the contacts recede from each other and as the newly created gap is bridged by a plasma. The arc plasma happens inside the insulation nozzle of SF6 self-blast interrupter which is newly developed as the next-generation switching principle. The ablation of PTFE nozzle is caused by this high temperature medium, the PTFE vapor from the nozzle surfaces flows toward the outlets and the pressure chamber. The vapor makes the pressure of the chamber increased by heat and mass transfer from the arcing zone. Because the rate of ablation depends on the magnitude of applied current, it decreases when the current goes to zero. The compressed gas inside the chamber flows reversely toward the arc plasma during this moment. According to this principle, the arc can be cooled down and the fault current can be interrupted successfully. In this study, we calculate arc plasmas and thermal-flow characteristics caused by fault current interruption inside a SF6 self-blast interrupter, and to investigate the effect of PTFE ablation on the whole arcing history.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1548-1549
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• 2011

High voltage cryogenic insulation issues need to be addressed in order to promote the commercialization of high temperature superconducting (HTS) equipment. As a fundamental step in the development of the optimum bushings for HTS devices, the breakdown characteristics of liquid nitrogen mixed with liquefied insulating gases such as $N_2$, $SF_6$, and $CF_4$ have been investigated. In order to investigate the possibility of substituting $CF_4$ gas for $SF_6$ gas for the bushings of HTS electrical equipment, AC withstanding voltage tests have been performed. In this paper, finding the maximum electric field $E_{max}$ using utilization factor ${\eta}$. This result is applicable to developing the real scale HTS equipment of the design parameters.

• Journal of Electrical Engineering and Technology
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• 제2권3호
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• pp.320-328
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• 2007

The sheath in underground power cables serves as a layer to prevent moisture ingress into the insulation layer and provide a path for earth return current. Nowadays, owing to the maturity of manufacturing technologies, there are normally no problems for the quality of the sheath itself. However, after the cable is laid in the cable tunnel and is operating as part of the transmission network, due to network construction and some unexpected factors, some problems may be caused to the sheath. One of them is the high sheath circulating current. In a power cable system, the uniform configuration of the cables between sections is sometimes difficult to achieve because of the geometrical limitation. This will cause the increase of sheath circulating current, which results in the increase of sheath loss and the decrease of permissible current. This paper will study the various characteristics and effects of sheath circulating current, and then will prove why the sheath current rises on the underground power cable system. A newly designed device known as the Power Cable Current Analyser, as well as ATP simulation and calculation equation are used for this analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1215_1216
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• 2009

Most transformer use insulating and cooling fluids derived from petroleum crude oil, but mineral oil is some possibility of environmental pollution and fire with explosion. vegetable oil fluids extracted from seed has superior biodegradation and fire-resistant properties including an exceptionally high fire point enhancing fire safety. In this study, it is aimed at the practicality of substituting natural ester dielectric fluid for mineral oil in liquid insulation system of transformers. As a rise in coil winding temperature has a direct influence on transformer life time, it is important to evaluate the temperature rise of coil winding in vegetable oil in comparison with mineral oil. Three transformers for the test are designed with 10KVA, 13.2KV, one phase unit. The temperature are directly measured in insulating oil of these transformers with the two sorts of natural ester and mineral oil dielectric fluid respectively. Temperature of vegetable oil transformers was similar to temperature of mineral oil transformer in the same design at 80% load and above.

• Journal of Advanced Marine Engineering and Technology
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• 제36권2호
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• pp.315-320
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• 2012

일반적으로 저압 회로 보호용 장치로는 ICCB(Insulated case circuit breakers), PCB(Power circuit breakers) 그리고 MCCB(Molded case circuit breakers)를 들 수 있다. 이들 중 가장 보편적으로 사용되는 배선용 차단기(MCCB)는 휴즈 또는 개폐기의 단점인 안전성, 제어성, 협조성 등을 보완한 것이다. 차단기의 성능은 사고전류 발생 시 트립 동작이 순간적이고, 절연능력이 뛰어나야 하므로 매우 중요하다. 따라서 차단기의 개폐 성능은 매우 중요하므로 개폐 기구부의 접촉자 구조 및 접점 그리고 링크구조 등에 대한 기구학적 연구가 필요하다. 본 논문에서는 저압차단기의 기구적 동역학 모델링과 해석을 수행하여 가동자의 개리속도가 빠를수록 차단특성에 유리하다는 결론을 얻었으며, 실제 실험을 통하여 이를 검증하였다.

• 한국지역지리학회지
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• 제10권1호
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• pp.151-157
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• 2004

1월의 clo 값은 대체로 삼지연 지역이 가장 높게 나타나고, 장전 일대의 동해안 지역이 가장 낮게 나타난다. 또한 해안 지역보다 내륙 지역이, 동해안보다 서해안이 clo 값이 높게 나타난다. 이는 지형적 영향과 기온과 풍속의 지역적 차이에 기인한다. 8월에도 삼지연, 해산 일대, 개마고원 등이 높게 나타나는데, 이는 지형적 영향으로 기온 저하와 풍속의 증가로 나타나는 현상이다. 특히 8월에는 삼지연을 중심으로 북동-남서 내륙지역으로 등치선이 만곡하고, 이 축을 중심으로 한 이외의 지역이 비교적 낮은 분포를 보인다. 이러한 원인으로는 위도, 지형 및 장마 이후의 고온 다습한 북태평양 기단의 영향과 강한 일사에 의한 지면 복사열의 방출에 있다고 사료된다.

• 조명전기설비학회논문지
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• 제21권8호
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• pp.121-128
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• 2007

본 논문에서는 세계최초로 내철형 주상변압기 코일의 권선을 일반적인 권선방법에서 Zig-Zag(가칭) 권선방법으로 설계 제작하는 방법을 제안하였으며, 또한 바니시 함침공정을 생략하고 단락강도 및 절연내력을 향상시킬 수 있는 내철형 변압기용 권선의 신프레임 구조개발 내용을 제안하였다. 기존의 주상변압기 권선방법에 비하여 전기절연 측면에서 층간 절연지의 사용매수 및 두께를 획기적으로 절감할 수 있는 장점이 있다. 또한 원가절감과 손실저감 및 단락기계력 대처능력이 우수함을 검증하였으며 국내전력회사 배전계통 주상변압기에 유용하게 활용할 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.251-254
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• 1998

The ($0.8BaTiO_3-0.1SrTiO_3-0.1MgTiO_3$)+$0.006Nb_2O_5$ ceramics were fabricated by conventional ceramic process. The dielectric property of specimen was investigated that the specimen was sintering temperature at 1,300C for 3hours and then annealed at $1,100^{\circ}C$ for 3hours in a atmosphere (air) to be painted on the surface with CuO paste. The results of the temperature and frequency are varied, the dielectric constant and loss tangent are unsuitable for BL capacitor. The dielectric constants were varied to be negative temperature coefficient(2.000-3,000) in the temperature range between -10 and $140^{\circ}C$, the dissipation factors (tan $\delta$) were some high(0.1-0.3). It was not grain insulation, in cause of the some difficult to be annealed temperature with CuO paste and fired atmosphere. But, we have some different annealing temperature and fired atmosphere, it will be suitable BL(Boundary Layer)capacitor.

• 한국태양에너지학회 논문집
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• 제31권3호
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• pp.67-72
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• 2011

The aim of this study is to evaluate how much would the building energy consumption be saved by applying DSSC BIPV window which is possible to control the transmittance and express the color in the office building. For this, physical characteristics such as transmittance and reflectance, U-factor of DSSC areanalyzed and an annual energy consumption that is connected to dimming control is calculated when DSSC BIPV window is applied by alternate clear window system. As a result, It is possible to reduce the anannual energy consumption as much as4.1% by just change the clear double window system to DSSC BIPV double window system because the major factor to reduce energy consumption in the office that has much cooling load than other building is SHGC. When the thermal insulation properties of DSSC BIPV window with low-e coating and making triple window are improved, energy saving ratio is about 9%. Plus, energy saving ratio of 25~28% in lighting energy consumption is possible when the dimming control system with DSSC BIPV window is adopt.