• 전기학회논문지
• /
• 제66권5호
• /
• pp.800-805
• /
• 2017

The accelerated thermal ageing of CSPE (chlorosulfonated polyethylene) was carried out for 16.82, 50.45, and 84.09 days at $110^{\circ}C$, equivalent to 20, 60, and 100 years of ageing at $50^{\circ}C$ in nuclear power plants, respectively. As the accelerated thermally aged years increase, the insulation resistance and resistivity of the CSPE decrease, and the capacitance, relative permittivity and dissipation factor of those increase at the measured frequency, respectively. As the accelerated thermally aged years and the measured frequency increase, the phase degree of response voltage vs excitation voltage of the CSPE increase but the phase degree of response current vs excitation voltage decrease, respectively. As the accelerated thermally aged years increase, the apparent density, glass transition temperature and the melting temperature of the CSPE increase but the percent elongation and % crystallinity decrease, respectively. The differential temperatures of those are $0.013-0.037^{\circ}C$ and, $0.034-0.061^{\circ}C$ after the AC and DC voltages are applied to CSPE-0y and CSPE-20y, respectively; the differential temperatures of those are $0.011-0.038^{\circ}C$ and $0.002-0.028^{\circ}C$ after the AC and DC voltages are applied to CSPE-60y and CSPE-100y, respectively. The variations in temperature for the AC voltage are higher than those for the DC voltage when an AC voltage is applied to CSPE. It is found that the dielectric loss owing to the dissipation factor($tan{\delta}$) is related to the electric dipole conduction current. It is ascertained that the ionic (electron or hole) leakage current is increased by the partial separation of the branch chain of CSPE polymer as a result of thermal stress due to accelerated thermal ageing.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
• /
• pp.29-29
• /
• 2010

Surface contamination and leakage current have caused operating problems. A flashover in a substation may result in destruction of an insulator or many others electrical equipment. Engineering plastics have good characteristic (light weight, good productivity and little of void) as compare with epoxy or porcelain insulators. Outdoor insulator must have resistance to contamination. However, it isn't suited to outdoor insulator because it is not hydrophobic. RTV(Room temperature vulcanizing) has a good property of hydrophobic and micro-filler. nano-filler have characteristics of obstructing exothermic reaction. In order to reduce the incidence of insulator flashover and damage, the silicon rubber contained with micro, nano-filler coating on surface of engineering plastics. In this paper, it compares tracking resistance, leakage current of the engineering plastic coated RTV with that of non-coated engineering plastic. And filled-composites performed much better than non-filled composites.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.19-21
• /
• 2003

In this paper, we studied on life-decision of underground cable of live-lines state. As all equipments have been wear, underground cables decided design-life on the whole 30 years because underground cable have been occurred aging as time goes. CV cable has been become about 30 years after installation in the South Korea, is come to a important point of time with estimation about life. Study target cable is 22 kV CV cables in this point of view and installation cable is about 10 years before and behind. Measurement method used dc leakage method of live-lines state that applied voltage of 50V in neutral point and data is analyzing result that is measured during 5 years. In this result, insulation resistance could confirm that change according to season and cause is effect of humidity, seasons and load current. Also, according as data is gone aging, insulation resistance by Weibull distribution could confirm functionally its decrease. As a result, the aging speed of cable that water tree is gone could confirm fastness very. Numerical analysis result, cable that water tree is not gone could confirm that life of cable that has passed 10 years remains about $10{\sim}20$ years.

• 조명전기설비학회논문지
• /
• 제22권10호
• /
• pp.34-40
• /
• 2008

본 논문에서는 최근 증가 일로에 있는 자동점멸식 보안등에 대한 안전점검 방안을 제시하였다. 기술적인 측면으로서 보안등주의 하부에 안전점검을 위한 별도의 점검함을 설치하고 점검원이 누설전류, 누전차단기의 정상적인 동작 상태, 절연저항 및 접지저항을 승주하지 않고 측정할 수 있도록 하였으며, 충전부에 대한 직접 접촉의 가능성을 최대한으로 경감함으로써 감전의 위험으로부터 자유로울 수 있도록 설계하였다. 본 연구의 결과물을 실용화함으로써 보안등에 대한 점검을 최대한 안전하고 효율적으로 수행하는데 일조할 수 있을 것으로 기대한다.

• 한국인터넷방송통신학회논문지
• /
• 제18권6호
• /
• pp.187-193
• /
• 2018

국내에서의 전력에 대한 수요는 점진적으로 증가하고 있는 추세이다. 수요에 대응하기 위한 발전소는 기능이 다양해지고 효율이 점차 커져야 한다. 발전소 내의 전력 기기에서 사고가 발생하면 막대한 경제적 손실 및 장애를 초래하게 된다. 사고 발생의 원인 중의 하나로서 절연 성능이 저하 된 케이블이 있다. 케이블 사고를 미연에 방지하기 위하여 절연의 상태를 감시하고 확인하여야 한다. 케이블 사고는 연결 부위인 접속에서 발생하는 사고가 대부분을 차지한다. 본 연구와 관련하여 우리는 접속부 상태를 판별하기 위한 장비를 개발하였고, 한국서부발전(주)의 현장에 설치하여 운용 중이다. 본 논문에서는 현장에서 설치 운용 중인 장비에 대한 설명과 더불어 설치 운용된 결과를 통해 케이블의 수명을 예측할 수 있는 고전압 케이블 접속재의 안정적 사용을 위한 온라인 감시진단기법 중에서 사고가 가장 빈번하게 발생하는 접속부에 대해 안정적인 사용을 위한 진단의 정확성과 신뢰성을 향상시키기 위한 연구를 하였다. 이 논문에서 하드웨어 구성을 위주로 우리가 개발한 장비를 소개한다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
• /
• pp.546-549
• /
• 2004

This paper describes the electrical characteristics of the polymer lightning arresters(L.As) used to protect distribution lines and power facilities from surge. For the relative comparison, the characteristics assessment was done for 2 states of L.As before and after water immersion treatment. The L.As for the comparative test were immersed with water of $95[^{\circ}C]$ considered a severe condition. After the immersion treatment, the assessment was carried out for material analyses in chemical structure(FTIR : fourier transform infrared spectrophotometer). Electrical performance measured insulation resistance measurement, leakage current measurement, critical operation voltage measurement etc.. In addition to, the results were compared with those for the L.As deteriorated in the field. Thus, the accelerative deterioration degree of polymer materials by immersion treatment was evaluated, by which the structural defects of the polymer L.As could be inferred.

• 조명전기설비학회논문지
• /
• 제24권3호
• /
• pp.27-32
• /
• 2010

The inundation of substation and ground power equipment breaks out every summer season in low-lying downtown areas and low-lying shores by torrential rain, typhoons and tsunamis. It has, in turn, caused replacement, social and economic costs for blackouts. For activity management regarding flood damage we produced a flood protection system which using the Pad transformer as a basic frame and is developed using pneumatic pressure. We tested safety concerns including insulation resistance and current leakage first for water tank flooding and, second, by an empirical test through supplying 22.9[kV]. We estimate that costs associated with flooding and power failure can be diminished by these advances toward creating a more reliable system.

• 한국전기전자재료학회논문지
• /
• 제34권1호
• /
• pp.16-20
• /
• 2021

In this study, we tried finding new materials to improve the stain resistance properties of polymer insulating materials. Using the filtered vacuum arc source (FVAS) with a graphite target source, DLC thin films were deposited on silicon and polymer insulator substrates depending on their thickness to confirm the surface properties, physical properties, and structural properties of the thin films. Subsequently, the possibility of using a DLC thin film as a protective coating material for polymer insulators was confirmed. DLC thin films manufactured in accordance with the thickness of various thin films exhibited a very smooth and uniform surface. As the thin film thickness increased, the surface roughness value decreased and the contact angle value increased. In addition, the elastic modulus and hardness of the DLC thin film slightly increased, and the maximum values of elastic modulus and hardness were 214.5 GPa and 19.8 GPa, respectively. In addition, the DLC thin film showed a very low leakage current value, thereby exhibiting electrical insulation properties.

• 한국인터넷방송통신학회논문지
• /
• 제15권3호
• /
• pp.169-173
• /
• 2015

이 논문은 사용한지 13년 지난 운전 중 22 kV 케이블시스템을, 7년 동안 절연저항을 측정하여 그 결과를 연구한 논문이다. 우리는 발전소에서 설치 운전 중인 고전압 케이블이 시간에 따라 성능이 악화되는 현상의 추세를 결정하는 수명지수를 파악하였다. 위한 논문이다. 케이블 시스템은 시간에 따라 절연 저항이 감소한다. 초기 케이블 시스템은 아레니우스 열화 곡선을 따른다. 초기에는 수명 지수 n값이 9로 설계하였고, 이후 n값을 상향하여 16으로 결정하였다. 이유는 고전압에서 케이블이 동작할 경우, n값이 클 때 파괴특성이 높지 않고, n값이 낮은 값에서 파괴특성이 높았기 때문이다. 그러나 전압열화에 의하여 와이블 프롯을 따른 v-t 특성에 의하여 n값은 10~11의 값을 갖는 것을 확인하였다. 과거 케이블 설계 시 정한 n=9의 이론적 근거와 n=16 으로 높아진 원인을 파악함으로써 누설 전류 및 절연 저항의 선형적인 변화를 확인하였다. 단기적으로는 운전 중 케이블 시스템의 진단 평가에 활용되며, 장기적으로는 발전소 부하에서 동작 중인케이블 시스템의 설치 및 운영에 있어서 원가를 절감하기 위한 노력에 기여하고자 한다.

• 한국전기전자재료학회논문지
• /
• 제31권5호
• /
• pp.307-312
• /
• 2018

Liquid phases in ZnO varistors cause more complex phase development and microstructure, which makes the control of electrical properties and reliability more difficult. Therefore, we have investigated 2 mol% $CaCO_3$ doped $ZnO-Co_3O_4-Cr_2O_3-La_2O_3$ (ZCCLCa) bulk ceramics as one of the compositions without liquid phase sintering additive. The results were as follows: when $CaCO_3$ is added to ZCCLCa ($644{\Omega}cm$) acting as a simple ohmic resistor, CaO does not form a secondary phase with ZnO but is mostly distributed in the grain boundary and has excellent varistor characteristics (high nonlinear coefficient ${\alpha}=78$, low leakage current of $0.06{\mu}A/cm^2$, and high insulation resistance of $1{\times}10^{11}{\Omega}cm$). The main defects $Zn_i^{{\cdot}{\cdot}}$ (AS: 0.16 eV, IS & MS: 0.20 eV) and $V_o^{\bullet}$ (AS: 0.29 eV, IS & MS: 0.37 eV) were found, and the grain boundaries had 1.1 eV with electrically single grain boundary. The resistance of each defect and grain boundary decreases exponentially with increasing the measurement temperature. However, the capacitance (0.2 nF) of the grain boundary was ~1/10 lower than that of the two defects (~3.8 nF, ~2.2 nF) and showed a tendency to decrease as the measurement temperature increased. Therefore, ZCCLCa varistors have high sintering temperature of $1,200^{\circ}C$ due to lack of liquid phase additives, but excellent varistor characteristics are exhibited, which means ZCCLCa is a good candidate for realizing chip type or disc type commercial varistor products with excellent performance.