• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.274-277
• /
• 2001

This paper describes the simulation study, conducted on the propagation characteristics of AE signal. In the case of gas insulation, such as SF6, the equipment is less affected by the environment condition than air insulation, because the component parts of equipment were placed in the enclosure, which is filled with compressed gas. But, when the breakdown in the electric insulation occurs, it takes much time and economical efforts to repair. Therefore it is very important to diagnose the equipment before the accident. And, in general, UHF and AE signal is the most common transducer to diagnose the state of the power equipment, so, in this investigation, we make a experimental apparatus with aluminum plate and transient analysis with ANSYS to observe the propagation characteristics of AE signal. Through the result of the analysis, we can make a further understanding on the propagation characteristics of AE signal, and get the fundamental skills for the GIS diagnosis.

• Transactions on Electrical and Electronic Materials
• /
• v.13 no.3
• /
• pp.149-152
• /
• 2012

The effects of amino silane coupling agent on the AC electrical treeing and breakdown behaviors in an epoxy/layered silicate (1 wt%) were examined in needle-plate electrode geometry. A layered silicate was exfoliated in an epoxy base resin by using our AC electric field apparatus. To measure the tree initiation and propagation and the breakdown rate, an alternating current (AC) of 10 kV (60 Hz) was applied to the specimen in needle-plate electrode arrangement with a $30^{\circ}C$ insulating oil bath. In the epoxy/amino silane system, the tree initiation time was 11.5 times higher and the breakdown time was 17.9 times higher than those of the neat epoxy resin. The tree initiation time in the epoxy/layered silicate (1 wt%) system with the amino silane was 2.0 times higher, and the breakdown time was 1.5 times higher than those of the epoxy/layered silicate (1 wt%) system.

• Journal of the Korean Society of Safety
• /
• v.11 no.4
• /
• pp.79-83
• /
• 1996

In this study, in attempt to develop a new application technique of discharge plasma, we employed a kind of discharging method called SPCP ( short for Surface discharge induced Plasma Chemical Process). Applications of SPCP have been widely used for years. Compact ozonizers to deodorize household equipments like refrigerators we a part of such applications. We took advantages of the compactness and durability of the SPCP electrode to set up an experimental apparatus for decompositing vapor of aromatic hydrocarbons such as toluene, benzene and xylenes, which are major substances given off In painting or washing processes and aggravate working conditions. Results obtained from this study are summarized as follows. 1) Aromatic hydrocarbon vapors of up to 2,000ppm were almost thoroughly decomposed at the flow rate of 4ℓ/min or lower under the discharge with electric power of 400 Watts. 2) In dry air, as the decomposition progresses, tar-like substance deposits on the discharging areas, which deteriorated the decomposition rate in the end. This substance, however, was almost thoroughly removed by keeping discharge in dry air containing no solvent vapor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.216-219
• /
• 2003

This paper presents the analyzing method for surface temperature distribution of a cast-resin transformer. For the study, the surface temperature of the transformer winding was measured and analyzed by a infrared thermography system. Alternating voltages were applied to simulate deterioration of the specimen transformer, and the hot-spot on the transformer surface was measured to analyze the condition for the winding. The hot line condition measured to the changes in surface temperature using infrared thermography camera and was set up the based of diagnostic method of the electric power apparatus. The results ould show the possibility of remote diagnosis using internet.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.232-233
• /
• 2005

The Surface of semi-conductive silicone rubber was treated by oxygen plasma to improve adhesion and electric performance in joints between insulating and semi-conductive silicone materials. Surface characterizations were assessed using contact angle measurement and Fourier transform infrared spectroscope (FTIR). Adhesion level was understood from T-peel tests between plasma treated semi-conductive and insulating material. Electrical breakdown strength was measured to understand the charge of electrical performance. From the results, the oxygen plasma treatment produces a significant increase in function group of containing oxygen which can be mainly ascribed to the creation of carbonyl groups on the silicone surface from the strength were improved. Therefore it is concluded then plasma treatment leads to decrease voids originating form poor adhesive, and the improve the adhesion in silicone interface. So we could obtain higher electrical design level of silicone material used for electrical apparatus using oxygen plasma treatment.

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.274-277
• /
• 1995

Recent environmental pollutions have intensified the need to develop zero emission vehicles. The most effect method of such solutions is EV. EV is high energy efficiency, easy to maintain, repair and is possible to make high performance control. However, because energy density of batteries is constrained and the distance covered one charge is short range. Also because EV has disadvantage of poor accelation ability, development of high performance battery is required for large scale use of EV. EV charger analogous to gas apparatus must also be developed immediately. Charger is discriminate between on-vehicle type and off-vehicle type. As off-vehicle type is able to charge fast and safe, inductive charging is considered. This paper aims to develope off-vehicle inductive charging system. Therefore, it achieved power factor correction converter, high frequency DC/AC inverter control algorithm development which gives proof validity through simulation and formulated the basic concept of high frequency transformer design for inductive charging.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.226-227
• /
• 2007

Nanostructured materials are attracting increased interest and application. Exciting perspectives may be offered by electrical insulation. Epoxy/Organoclay nanocomposites may find new and upgraded applications in the electrical industry, replacing conventional insulation to provide improved performances in electric power apparatus, e.g, high voltage motor/generator stator winding insulation, dry mold transformer, etc. This paper shows that electrical and thermal properties of epoxy/organoclay nanocomposites insulating materials for dsc, dielectric constant, I-V characteristics, breakdown volatge, can improve significantly with respect to the basic, virgin materials.

• Journal of Advanced Marine Engineering and Technology
• /
• v.14 no.4
• /
• pp.57-66
• /
• 1990

In the design of an electric power plant, the capacity to meet the peak load demand is one of the important factors to be considered. This peak load usually occurs when the most of the cooling air conditioning systems are being operated during daytime in summer season, which inevitably entails the construction of an additional electric power plant. This study is aimed to carry out a basic experiment for the development of a cooling air conditioning system using the ice energy by the surplus electric power during the night-time. The experimental apparatus consists of four major parts; (1) the heating section consisting of the air duct and I.D. fan, (2) the cold section with the ice chamber, (3) the bundle of heat pipes made in a form of the staggered arrangement with ${C_y}/{d_o}$=2.0 and ${C_x}/{d_o}$=1.73, (4) the refrigerator system to cool down the ice chamber. This study involves an intensive experiment concerning the convective heat transfer of the air flow surrounding the bundle of heat pipes. This major experimental parameters are the amount of working fluid, the velocity of air and the working temperature. The major findings of the present study are as follows; (1) The optimum amount of the working fluid necessary for the horizontal heat pipes is much more than that for the vertical type. (2) The convective heat transfer coefficients of the air are coincided with the empirical equations of Grimson and ${\breve{Z}ukauskas}$. (3) The equation of the mean heat transfer coefficient obtained in the present study is ${N_um}=0.32 {Re_max^{0.63}}$.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2976-2983
• /
• 2013

Interest in reducing standby power is increasing because of electric power shortages. Most of electric equipment are in standby state that does not use a function of the original, most electronic devices consume a lot of electric power even in standby mode. In many countries, research on the smart plug is advanced in order to prevent power consumption due to standby state. However, due to the nature of the function, expensive in many case. These smart plugs would be to cut the standby power using motion detecting sensor or pattern control of the user. Theses features have no advantages because of malfunction of motion detecting sensor and in accordance with the diversification ot user's pattern. In this study, developing a multi-smart plug system that linked with bluetooth function of user's smart phone. Using smart phone bluetooth function, determination of the position of the user. The suggestion smart plug cutting the standby power of the electronic apparatus. It was confirmed that it is able to reduce the power consumption according to the location of the user.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.8
• /
• pp.1560-1565
• /
• 2011

The environmental pollution caused by green-house gases such as $CO_2$ and $SF_6$ has been becoming the main issue of industrial society. Many developed countries are making efforts to minimize the amount of $CO_2$ emission come from the operation of high voltage electrical apparatuses. As a part of these efforts, 180 countries signed the Kyoto Protocol in 1997 to cut back on their green-house gas emissions. Nowadays, the study on the development of dry air insulated switchgear (DAIS) which is known as an eco-friendly electrical apparatus is in progress. A DAIS is advantageous for minimizing the effect of impurities and enhancing the dielectric characteristics over an air insulated switchgear (AIS) by applying constant pressure to an enclosed cubicle. Therefore, a study on the electrical insulation performance of dry air as a gaseous insulation medium is conducted in this paper to substitute a gas insulated switchgear (GIS) for DAIS. As results, it is verified that the AC dielectric characteristics of dry air are similar to those of air and the lightning impulse dielectric characteristics of dry air are superior to those of air at 1bar pressure condition. However, dry air is of inferior dielectric characteristics to $SF_6$ at 4bar pressure condition. Finally, it is suggested that the internal pressure of DAIS should be over 4bar pressure to develop a high voltage switchgear which has similar electrical performance to a conventional GIS. Also, the empirical formulae on calculating the maximum electric field intensity at sparkover of dry air are deduced by experiments according to pressures. It is expected that these results are helpful to design and develop a high voltage electrical apparatus.