• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.178-180
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• 1993

The back bias effect on the breakdown voltage of SOI $p^+$-n diode is investigated. The breakdown voltage of the SOI $p^+$-n diode increases with the applied back bias. When the cathode electrode is used as a back bias, it is necessary to put the dielectric material between the Si-substrate and the bottom cathode electrode.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.263-267
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• 2016

In this paper, we analyzed the electrical characteristics of NPT planar and trench gate IGBT after designing these devices according to design and process parameter. To begin with, we have designed NPT planar gate IGBT and carried out simulation with T-CAD. Therefore, we extracted design and process parameter and obtained optimal electrical characteristics. The breakdown voltage was 724 V and The on state voltage drop was 1.746 V. The next was carried out optimal design of trench gate power IGBT. We did this research by same drift thickness and resistivity of planar gate power IGBT. As a result of experiment, we obtain 720 V breakdown voltage, 1.32 V on state voltage drop and 4.077 V threshold voltage. These results were improved performance and fabrication of trench gate power IGBT and planar gate Power IGBT.

• 전기의세계
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• v.24 no.1
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• pp.63-69
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• 1975

This study investigated the characteristics of fatigue breakdown caused by the impulse voltage of heat treated polyethylene cables through fault currents. This study attempted to obtain the badic data on the insulation design by the repeated load of impulse voltage wave zone (1*40.mu.s) on heat treated polyethylene cables. Besides this study also analysed the data involving their durability by means of the Weibull distribution. An analysis of the breakdown characteristics based upon the repeated load of impulse voltage has revealed that worn out deteriorative breakdown existed at a high voltage near the initial breakdown voltage, and that random breakdown was discovered at a voltage somewhat lower than the initial breakdown voltage. These phenomena were more remarkable especially in the case of the higher temperature treated cables.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.321-326
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• 1998

Electrical breakdown characteristics of liquid nitrogen($LN_2$) taking into consideration for application of high $T_c$ superconductor is very important. Also $LN_2$ will be used as both coolant and insulator in superconducting generator. In this paper, we investigated ac breakdown characteristics of cryogenic nitrogen gas above a $LN_2$ for rod-to plane electrode configuration. As result the breakdown mechanism of $LN_2$is dependence on bubble effect. And breakdown voltage is a ratio on bubble s size but electrodes arrangement is to make no difference. The breakdown voltage decreases slightly with increasing flow velocity, it again decreases abruptly with increasing flow velocity. These results were interpreted as the within pressure of rod electrode and Maxwell force.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.284-286
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• 1994

This paper describes the dielectric characteristics of $SF_6$ gas in non-uniform electric filed under lightning under lightning impulse and oscillating impulse voltages. The breakdown voltage-time characteristics and the breakdown voltage-pressure characteristics are measured over a pressure range extending from 0.1 to 0.5 [MPa] fur the coaxial electrode with a needle protrusion. The curvature radius of needle protrusion is 0.3[mm]. Also, the growth of the predischarge is simultaneously observed. As a result the polarity effect is pronounced, and the breakdowns voltage under the oscillating impulse voltage are higher than those under the lightning impulse voltage. It is found that the breakdown mechanism md predischarge phenomena ate closely related with the polarity and waveforms of the testing voltage.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.97-102
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• 2012

To predict accurately the breakdown voltage in air at atmospheric pressure, a fully coupled finite element analysis combining the hydrodynamic diffusion-drift equations with Poisson's equation is proposed in the current paper. As three kinds of charged transport particles are nonlinearly coupled with spatial electric fields, the equations should be solved by an iterative numerical scheme, in which secondary effects, such as photoemission and photoionization, are considered. The proposed method has been successfully applied to evaluate the breakdown voltage in circular parallel-plane electrodes. Its validity has been proved through the comparison of the predicted and experimental results. The effects of numerical conditions of the initial charge, photoemission, and background ionization on the discharge phenomena are quantitatively assessed through Taguchi's design of experiment method.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1978-1980
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• 2000

Because the interfaces between two different materials are the weak-link in the underground power transmission systems, they affects the stability of insulation systems. In this paper, Epoxy/EPDM interface is selected and investigated the optimum condition by variation of interfacial conditions such as roughness of surface, spreading of oils, interfacial pressure and temperature. The breakdown times under the constant voltage below the breakdown voltage were also gamed. The breakdown voltage at the after laying time equivalent to is calculated by the V-t characteristic and the inverse power law. When this is done. the characteristic life exponent n is used and the long time breakdown voltage can be evaluated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.170-173
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• 2003

In this paper, we proposed a new bulk LDMOS structure which can be used for RF application, and its fabrication steps were introduced. The simulated devices consist of three types: Bulk device, SLB(SOI Like Bulk), and SOI device. As a result of process and device simulation, we showed electrical characteristics, such as threshold voltage, subthreshold slope, DIBL(Drain Induced Barrier Lowering), off-state current, and breakdown voltage. In this simulation study, the lattice temperature model was adopted to see the device characteristics with lattice temperature during the operation. SLB device structure showed the best breakdown characteristics among the other structures. The breakdown voltage of SLB structure is about 9V, that of bulk is 7V, and that of SOI is 8V.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.446-454
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• 2016

In this paper, we present experimental results of the soil discharge characteristics as a function of moisture content when a 1.2/50-㎲ lightning impulse voltage is applied. For this study, laboratory experiments were carried out based on factors affecting the transient behavior in soils. The electrical breakdown voltages in soils were measured for a 0-6% range of moisture content for sand and a 0 - 4% range of moisture content for gravel. A test cell with semi-spherical electrodes buried face-to-face in the middle of a cylindrical container was used. The distance separating the electrodes is 100 mm. As a result, the time-lag to breakdown in soils decreases as the amplitude of applied voltage increases. The time-lag to initiation of ionization streamer is decreased, with an increase in the moisture content. However, the formative time-lag is rarely changed. The behavior of soil discharges depend not only on the type of soil and its moisture content but also on the amplitude of the impulse voltage. When the test voltage is applied repeatedly, electrical breakdown occurs along different discrete paths, leading radially away from the injected electrode. i.e., the fact that the ionization streamers propagate in different paths from shot to shot was observed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.775-778
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• 2000

In this paper, the life-time of macro interface between Epoxy/EPDM which consists in underground power cable joints is predicted. The electrode system of specimen is designed by FEM(finite elements method). The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied, the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law, and the long breakdown life time can be evaluated.