• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1933-1935
• /
• 2000

In this paper, it was tried to find out the minimum measurement range in the diagnosis of insulators using thermal image camera, for the purpose, leakage currents and thermal images were observed simultaneously for the insulators of which surface had been artificially polluted by salt fog. As a result. the surface temperature was increased with leakage currents. Also, the results of AC breakdown tests for the insulator of which temperature rise was more than 1 $^{\circ}C$ showed to be bad. Therefore, through the study on the relationship between leakage current, temperature rise and AC breakdown voltages, the diagnosis of the insulator in site would be possible using the thermal image camera.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.179-182
• /
• 2002

XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

• 한국표면공학회지
• /
• 제52권5호
• /
• pp.275-281
• /
• 2019

Anodization is widely used to enhance the properties of aluminum, such as hardness, electric resistance, abrasion resistance, corrosion resistance etc. But these properties can be enhanced with additional process. According to the partial crystallization of oxide layer with post heat treatment, enhanced hardness can be expected with partial crystallization. In this study, post heat treatments were applied to the anodized aluminum alloys of Al6061 to achieve the partial crystallization, and crystallizations were evaluated with the reduced breakdown voltages. Interestingly, remarkable enhanced hardness (21~29%), abrasion resistance (26~62%), and reduced breakdown voltage (24~44%) were observed for the sulfuric acid anodized samples when we annealed the anodized samples with 1hour post heat treatment at $360^{\circ}C$. For the Al5052 alloys, a lot of cracks were observed when we applied the post heat treatment.

• ETRI Journal
• /
• 제37권1호
• /
• pp.97-106
• /
• 2015

In this paper, MOS-triggered silicon-controlled rectifier (SCR)-based electrostatic discharge (ESD) protection circuits for mobile application in 3.3 V I/O and SCR-based ESD protection circuits with floating N+/P+ diffusion regions for inverter and light-emitting diode driver applications in 20 V power clamps were designed. The breakdown voltage is induced by a grounded-gate NMOS (ggNMOS) in the MOS-triggered SCR-based ESD protection circuit for 3.3 V I/O. This lowers the breakdown voltage of the SCR by providing a trigger current to the P-well of the SCR. However, the operation resistance is increased compared to SCR, because additional diffusion regions increase the overall resistance of the protection circuit. To overcome this problem, the number of ggNMOS fingers was increased. The ESD protection circuit for the power clamp application at 20 V had a breakdown voltage of 23 V; the product of a high holding voltage by the N+/P+ floating diffusion region. The trigger voltage was improved by the partial insertion of a P-body to narrow the gap between the trigger and holding voltages. The ESD protection circuits for low- and high-voltage applications were designed using $0.18{\mu}m$ Bipolar-CMOS-DMOS technology, with $100{\mu}m$ width. Electrical characteristics and robustness are analyzed by a transmission line pulse measurement and an ESD pulse generator (ESS-6008).

• 대한전자공학회논문지
• /
• 제20권3호
• /
• pp.33-39
• /
• 1983

종래의 쇼트키 다이오드들이 가지는 금속중첩 및 P보호환 구조와 비교하여 금속-반도체 접합면 가장자리에 얇은 계단형 산화막(약1000Å) 구조를 갖는 새로운 소자들을 설계 제작하였다. 별은 계단형 산화막의 형성은 T.C.E. 산화공정으로 처리하였으며 이러한 새로운 소자들의 항복현상을 비교 검토하기 위하여 이들과 함께 동일한 소자 크기를 갖는 종래의 금속 중첩 쇼트키 다이오드와 P보호환 쇼트키 다이오드를 같은 폐이퍼상에 집적시켰고 항복전압에 대한 측정을 통해 고찰해 본 결과 금속-반도체 접합면 가장자리에 얇은 계단형 산화막 구조를 갖는 소자들은 종래의 쇼트키 다이오드들에 비해 항복현상에 있어서 월등한 개선을 보여 주는 것으로 나타났다.

• 한국전기전자재료학회논문지
• /
• 제11권2호
• /
• pp.121-127
• /
• 1998

In this paper, to develop PTCR(Positive Temperature Coefficient of Resistance) thermistor with high withstanding voltage, Ca were added to. the compositions of $(Ba_{0.9165-X}-Sr_{0.08}-Ca_X-Y_{0.0035})TiO_3+MnO_2$ 0.02wt%+$SiO_2$ 0.5wt%. the effects of Ca additions were researched according the increasing of Ca from 0[mol%] to 20[mol%], and the electrical properties were investigated. As increasing Ca additions from 0[mol%] to 20[mol%], the grain size of the specimens was reduced from 11.1[${\mu}m$] to 6.15[${\mu}m$], and also the sintered density was reduced from 5.43[$g/cm^3$] to 5.05[$g/cm^3$] and their the breakdown voltages were increased from 163[V/mm] to 232[V/mm]. It is shown that the breakdown voltage was increased with amount of Ca additions.

• Transactions on Electrical and Electronic Materials
• /
• 제9권5호
• /
• pp.186-192
• /
• 2008

Cross linked polyethylene (XLPE) insulators are used as insulation in ultra-high voltage electric power cables. This study investigated the electrical properties of XLPE at different temperatures. The electrical properties of the changing tree phenomenon was examined as a function of temperature applied to the electrical conductors by measuring the partial discharge at $25^{\circ}C$ to $80^{\circ}C$ and applied voltages to the electrodes ranging from 1 kV to 40 kV. The activity of the partial discharge was examined at various temperatures using the K-means distribution. The results revealed the specimen at $80^{\circ}C$ to have the lowest inception voltage and breakdown voltage. In addition, the core of clusters was moved $0^{\circ}$ and $180^{\circ}$ at the positive region and $180^{\circ}$ and $360^{\circ}$ in the negative region in the K-means. The distribution of clusters was concentrated on the inception condition and spread out widely at the breakdown voltage.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.57-59
• /
• 2005

전력용 IC에서 높은 항복전압의 구현을 위해서 RESURF구조가 많이 사용되고 있다. 하지만 하나의 칩 위에서 다양한 항복전압을 가지는 소자를 구현하기 위해서는 에피층의 농도가 각각 달라져야하는데 이는 공정상의 복잡함과 비용의 문제를 수반하게 된다. 이런 문제점에 따라 본 연구에서는 전력용 IC에서 항복전압이 다른 다수의 LDMOST를 추가 공정없이 에피 영역의 길이를 조절하여 구현할 수 있음을 해석적인 방볍과 2차원 소자 시뮬레이터를 이용하여 확인하였다.

• 대한전자공학회논문지SD
• /
• 제45권6호
• /
• pp.22-27
• /
• 2008

4H-SiC의 전자와 정공의 이온화계수 $\alpha$와 $\beta$로부터 유효이온화계수 $\gamma$를 추출함으로써 4H-SiC 쇼트키 다이오드의 항복전압과 온-저항을 위한 해석적 모델을 유도하였다. 해석적 모델로부터 구한 항복전압을 실험 결과와 비교하였고, 도핑 농도 함수의 온-저항도 이미 발표된 결과와 비교하였다. 항복전압은 $10^{15}{\sim}10^{18}\;cm^{-3}$의 도핑 농도 범위에서 실험 결과와 10% 이내의 오차로 잘 일치하였다. 온-저항을 위한 해석적 결과는 $3{\times}10^{15}{\sim}2{\times}10^{16}\;cm^{-3}$의 범위에서 실험 결과와 매우 잘 일치하였다.

• 조명전기설비학회논문지
• /
• 제17권2호
• /
• pp.95-101
• /
• 2003

본 논문에서는 모의 GIS를 에폭시로 코팅하고, 금속이물 혼입시의 부분방전, 부상전압, 절연파괴전압 등을 측정하여, 코팅하지 알았을 경우와 비교 분석하였다. 또한, 여러 경우의 절연사고를 모의하기 위해, SF$_{6}$/$N_2$가스 혼합비, 금속이물의 재질, 직경, 코팅두께, 압력 등을 변화시키면서 전기적특성을 관찰하였다. 실험결과, 코팅두께가 증가할수록 부분방전개시전압이 증가하였으며, 부분방전의 크기는 감소하였다. 또한 철합금 파티클의 부상전압이 구리파티클보다 높았으며, 직경이 증가할수록 부상전압도 증가하였으며, 코팅두께가 두꺼워질수록 절연파괴 전압이 증가하였다. 이상의 연구결과 GIS를 에폭시로 코팅함으로써 절연성능을 향상시킬 수 있음을 확인하였다.