• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.560-561
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• 2005

For the insulation design of a HTS cable, the withstand voltage of three kinds were proposed. One of them is the AC design withstand voltage, another is the impulse design withstand voltage, and the other is the partial discharge inception stress. However, the multi-layered effect was not considered on insulation design of a HTS cable at existent design process. Therefore in this paper, the electrical breakdown characteristics by multi-layered effect of LPP insulation paper were investigated. Based on these results, the insulation thickness of 22.9 kV class HTS cable was designed, and compared with existent design process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.7
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• pp.645-649
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• 2007

Partial discharge(PD) test for simulated insulation defects of used hydro generator stator winding was conducted to analyze the PD Parameters. Simulated insulation defects are classified by 5 types corona, slot, internal, multi and aging defect. Phase resolved partial discharge, statistical parameter (skewness, kurtosis), PD magnitude as a function of the test voltage(Q-V curve) and PD magnitude change under test voltage for 2 minutes are used as PD parameters. The analysis of PD parameters by 4 types are proved to be useful methods. In particular, PD parameter characteristics of aging defect could help to assess the aging condition of stator winding because aging defect has more weak insulation strength than other insulation defects : PD distribution is wide and flat, PD rises rapidly near $0^{\circ}\;and\;180^{\circ}$ and Q-V curve rises sharply and then gently drops.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.8-13
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• 2019

Weight and elongation changes of IV and HIV insulations were measured simultaneously at several given temperature of $80^{\circ}C$, $90^{\circ}C$ and $100^{\circ}C$. And the lifetime was predicted using the Arrhenius model. Based on the initial weight values, a 50% elongation reduction was seen at 6.96% for the IV insulation and 10.29% for the HIV insulation. The activation energy from the slope of the lifetime regression equation was calculated as 92.895 kJ/mol(0.9632 eV) for the IV insulation and 95.213 kJ/mol(0.9873 eV) for the HIV insulation. Also, the expected lifetime at the operating temperature of $30^{\circ}C$ to $90^{\circ}C$ is 2.02 to 94.32 years, and longer lifetime was predicted on HIV insulated wires than on IV insulated wires. As a result, it was found that the thermal characteristics of the HIV insulated wires were about 12.44% better than those of IV insulated wires under the same conditions of use.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.277-278
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• 2018

Improvement of insulation performance of buildings is a major part. Adiabatic method The adiabatic method minimizes the heat loss of the building. External insulation uses insulation to prevent fire. Ambient air hazards are less prone to fire. When a fire occurs, a phenolic pattern is formed and bond strength with the wall increases. EPS insulation and phenol foam were used to compare external heat transfer and external heat transfer. The heat transfer properties of phenolic foam and styrofoam were evaluated as follows. In the mortar and styrofoam structure, the problem of styrofoam reaching the burning point occurred before the collapse of the mortar, and the phenol foam had a problem in that when the direct fire was continued on the phenol foam. The characteristics of continuous infiltration appeared. In the case of mortar and phenol foam + styrofoam, the heat penetrated into the interior due to the shrinkage due to the shrinkage of the carbon screen on the phenol foam. However, when reinforced with glass mesh on the outer surface, And to reduce infiltration.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.141-149
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• 2007

This paper introduce to improve the reliability of the expected service life and the insulation condition evaluation of the high voltage induction motors by assessing, comparing and analyzing the correlation between the dielectric properties of the off-line insulation diagnostic test and dielectric strength on the insulation breakdown test. The insulation diagnostic tests include insulation resistance, polarization index(P.I.), dissipation factor($tan{\delta}$), maximum partial discharges($Q_{max}$) and AC breakdown test. This study evaluated the correlation between insulation diagnostic test and AC breakdown test for stator winding of high voltage induction motor. On the basis of these test results, we expect that this study can be used for effectively assessing the results of insulation diagnostic tests for similar class induction motors in service at industrial field.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.607-612
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• 2002

This paper presents the first domestic model product of hybrid Insulation low-loss type pole transformer, with increased overload ability, increased life, reduced loss, focusing improved short-circuit characteristics. The capacity of this transformer is 100 KVZ, rates first voltage 13200 V and secondary voltage 230/115 type. The volume of model transformer that was produced in high temperature using hybrid insulation can be reduced to 10-20% in comparison with that of present transformer with the same capacity. In this paper, we did short-circuit test and tested general characteristics of model transformer. In addition, we suggested design application new concept and methods thorough this experiment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.151-154
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• 2005

In this paper the experiments of insulation characteristics by temperature change of $SF_6$ gas and liquid $SF_6$ in model GIS(Gas Insulated Switchgear) were described. From this results, the breakdown voltage was increased with a drop of temperature and an increase of the inner pressure in model GIS. The ability of insulation in liquid $SF_6$ was higher than that of the highly pressurized $SF_6$ gas. A liquid $SF_6$ discharge characteristics was caused by bubble formed evaporation of liquid $SF_6$ and bubble caused by high electric emission. It is considered that these result are fundamental data for electric insulation design of superconductor and cryogenic application machinery which will be studied and developed in the future.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1670-1672
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• 2001

In compared with air insulated switchgear GIS has a high efficiency and confidence. Insulation method using $SF_6$ gas has a very excellent insulation characteristics for high voltage equipment but has a characteristics that insulation heredity is changed for internal unequal electric field. So analysis of electromagnetic field in GIS is very important basic data for structure design and trouble diagnosis process. In compared with established method, SNM in this paper observes variation of the electromagnetic field with real time and get result very similar to measurement. In order to know the variation of electromagnetic field distribution for transient response for time and position, variations are observed when metal particles are moving fast.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.2-4
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• 2014

The preferred dimensions of the test opening for a window are $1250mm{\times}1500mm$ according to ISO 10140-1:2010. But tests done at actual size generally because not standardized for windows. In this study, we know the sound insulation characteristics by the size of windows using the single windows and double windows, consider the more effective performance evaluation method.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.531-533
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• 2000

In compared with air insulated switchgear, GIS has a high efficiency and confidence So the transformer substation can be reduced the size to 1/10. Insulation method using $SF_6$ gas has a very excellent insulation characteristics for high pressure equipment but has a characteristics that insulation heredity is changed for internal unequal electric field. So analysis of electromagnetic field in GIS is very important basic data for structure design and trouble diagnosis process. In compared with established method, SNM in this paper observes variation of the electromagnetic field with real time and get result very similar to measurement. In order to know the variation of electromagnetic field distribution for transient response for time and position, variations are observed when the spacer is bonded and metal particles are moving fast.