• Journal of IKEEE
• /
• v.23 no.3
• /
• pp.811-816
• /
• 2019

The silicon-adsorbed oxygen(Si-O) superlattice grown by ultra high vacuum-chemical vapor deposition(UHV-CVD) was introduced as an epitaxial barrier for silicon quantum electron devices. The current-voltage (I-V) measurement results show the stable and good insulating behavior with high breakdown voltage. It is apparent that the Si-O superlattice can serve as an epitaxially grown insulating layer as possible replacement of silicon-on-insulator(SOI). This thick barrier may be useful as an epitaxial insulating gate for field effect transistors(FETs). The rationale is that it should be possible to fabricate a FET on top of another FET, moving one step closer to the ultimate goal of future silicon-based three-dimensional integrated circuit(3DIC).

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.2
• /
• pp.341-347
• /
• 2009

As a right-of-way security for the high power transmission line tower construction is becoming more and more difficult, the friendly environmental compact tower design is required. For a proper insulation for the compact tower, the polymer material are being tried. Some countries has already adapted, in the various polymer application and management data, polymer arm insulator to the transmission tower, and shown a stable operation. However, in our country, the polymer arm insulator has left much to be desired in the installation on the transmission line tower. But polymer material has been developed by high strength and technology and is expected to be used in various electric equipments. The polymer arm insulator is a one of good electric insulation materials to expand the power supply capacity in the rapid power demand increasement In this research, the new polymer am insulator is designed and its electric specifications are analyzed. Its mechanical specifications is verified through the field test on the compact tower which is modified by the polymer arm insulator.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.9
• /
• pp.430-435
• /
• 2002

The $SF_{6}$ gas insulated power equipments have the insulation systems which are composed of $SF_{6}$ gas and insulation paper. It is repored that their insulation abilities are influenced by the $SF_{6}$ gas gaps in those insulation systems and gas pressures. This paper describes partial discharge phenomena with $SF_{6}$ gas pressures in insulation system of $SF_{6}$ gas-insulation paper Specimens of $SF_{6}$ gas-insulation paper were prepared and aramid paper was used as insulation paper. Partial discharge inception voltages(PDIV) and breakdown voltages for the existence of $SF_{6}$ gas gaps were measured by short term tests with gas pressures. Also, average PD quantities and pulse counts, life times of each specimens were calculated from the results of long term aging tests with gas pressures. It was found that the $SF_{6}$ gas gaps decrease increasing rates of PDIV and brealdown voltages according to gas pressure increase and the insulation breakdown caused by the smaller PD quantities than 1[pC] at the high gas pressure of 300kPa is due to the increase of energy density with increase of gas pressure.

• Fire Science and Engineering
• /
• v.23 no.2
• /
• pp.62-66
• /
• 2009

In this study, we study the damage by burning characteristics of insulating material of RCD (Residual Current Device) used in Korea. The insulating materials of RCD manufactured by three manufacturers are used as the sample. We compare and analyze the thermal decomposition characteristics, combustion characteristics and tracking characteristics of samples. The TGA and Mass Loss Calorimeter meeting the requirements for the ISO5660 (Fire tests-Reaction to Fire, part 1) are used for analyzing the thermal decomposition characteristics and combustion characteristics respectively. In addition, the tracking characteristics are analyzed according to standard of KSC IEC 60112 known as the test used for measuring the resistance tracking and comparison tracking indexes. The study results show that the resistance tracking property of insulating material provided by A Company is highest. Also, the test results show that the resistance tracking property of insulating material provided by B Company is lowest. However, the thermal stability of insulating material provided by this company is excellent at high temperature of above $350^{\circ}C$. In addition, the test results show that the thermal stability of insulating material provided by C Company is highest at temperature of below $400^{\circ}C$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.1
• /
• pp.53-58
• /
• 2000

In this paper, the variable mechanical strength and dielectric breakdown strength of epoxy composites were measured at boiling absorption condition in order to observe the influences of moisture in out door use. Also, in order to improve water resistance of matrix resin, IPN(interpenetrating polymer network) method which had been already reported, was introduced and the influence was investigated. As Adding filter(SiO2) classified by o[phr], 50[phr] and 100[phr] to two kinds of matrix resin, six kinds of specimens were manufactured. As a result, it was confirmed that the moisture absorption rate was increased and mechanical strength and dielectric breakdown strength were degraded with boiling time and filler content increasing. On the other hand, it was confirmed that moisture absorption rates were decreased and the degrading rates of mechanical strength and dielectric breakdown strength were lowered according to improvement of adhesion strength in case of IPN specimens.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.8
• /
• pp.129-135
• /
• 2007

It is necessary to study on the prevention and the management of electrical facilities because the electrical fault took place at the dust occurrence area due to environmental pollution. In particular, the dust accumulates easily on insulation material which is exposed an external long time. Therefore, we measured surface leakage current and surface variation of insulation material due to the dust and salt-water. From the results, the surface of bakelite is bad effect for salt-water than other material. The surface leakage current increases by repeated salt-water pollution and the surface of material is carbonized with arc occurrence. Also, it is need to variation of surface coating and shape of material to repress a leakage current on electrical material.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.7
• /
• pp.84-93
• /
• 2007

The pole transformer is one of the most important facility to insure the stability of electric power supply. which distributes electricity to customers directly. However there are a lot of defects which are caused by manufacturing fails(in 3 years) or deterioration (in 13 years), so we need a more improved transformer which insures quality. This thesis talks about the development of the new-type transformer using the hybrid insulation that is durable thermally, mechanically, and electrically. It would show how to lay out and produce the transformer using the hybrid insulation. And finally we are sure that we could increase the utilization rate of a transformer by 160% as compared with its own capacity through the overload test. Also, we carried out the examination about the short-circuit and insulation with a 100[kVA] model transformer, so that we expound the analysis of magnetic-mechanical forces intensity and the measure for improving short-circuit efficiency.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.11
• /
• pp.1350-1357
• /
• 1988

The dual dielectric films have been grown on single-crystalline silicon substrates with the thickness ranging from 125A to 180A at various gas and temperature conditions by using rapid thermal process that included independent nitridation step. The film characteristics and their dependence on the contents of the hydrochloric gas and the processing time have been studied. By the addition of the hydrochloric gas, the initial oxide thickness was significantly changed, but after sequential nitridation processes the thickness of the films was nevertheless a little bit varied within 10A. All the samples of the dual dielectric films show the increased breakdown voltages in proportion to the additive contents of the hydrochloric gas and also show the higher breakdown strengths than the thermal oxide and nitrided oxide films grown by the conventional furnance process or the rapid thermal nitridation process that was composed of the dependent nitridation cycles.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.5
• /
• pp.237-242
• /
• 2014

In this paper, we find out the lifetime index in order to determine the time-dependent trend of deteriorating performance of 6.6kV high-voltage power cable in operation at a power station. The cable systems used in our study have been in operation for 13 years. With measurements for the 13 years, we analyzed the insulation resistances. By developing measuring equipment (comprized mainly of transformer, temperature sensor, and LPF) operating by the three-phase electric power, we analyzed the changing characteristics of insulation resistance of power cable. In contrast to 22kV cables, 6.6 kV cables have thicker insulation. Therefore the characteristics of 6.6kV cables are different from that of 22kV cables. The study found that as time passes, the insulation resistance does not decrease continuously; it decreases to a certain value, then does not decrease any more and shows properties of oscillation. We could not detect the process of deterioration in the preceding twelve years. The cable system showed great stability so that deterioration was not apparent. In this case, it is not possible to measure the future life indices of power cables because the lifetime indices are not predictable

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.4
• /
• pp.30-37
• /
• 2002

This paper reports on the results of weathering test, tracking test and salt-fog test of various kinds of cycloaliphatic epoxy systems. UV irradiation dramatically induced the loss of surface hydrophobicity due to the chain scission attack at the surface under UV irradiation. It could be seen that samples containing an UV absorbent/antioxidant and a silicone oil additive have a good performance in weathering test, while ATH(alumina tri-hydrate) filled ones have high resistance against tracking failure than others. Under salt fog chamber test, specimens mixed with silicone oil are able to suppress leakage current development. It was thought that silicone oil mixed into cycloaliphatic epoxy system could lead to lower the surface energy and to retain hydrophobic properties for a long time, which are desirable for outdoor use.