• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1924-1926
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• 2000

This paper deals with the multiresolution analysis of wavelet transform for partial discharge(PD).PD is an electrical discharge that only partically bridges the insulation performance of electrical equipment in high voltage. PD signal is very sensitive and difficult to suppress strong noises such as narrow-band radio frequency noise and random noise. In recently, wavelet transform has become a powerful tool to analysis and process signals in various science and technology fields. In this paper, daubechies family is adopted for the research of the characteristics of PD signals. The results show that the kurtosis is increased with discharge process and skewness is decreased with discharge process, but when PD occured positive range then skewness is increased. Segment 7, 8, 9, 10, 11 values is increased with discharge process, so phase distribution is characterized by 210$\sim$330 ranges.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.33-41
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• 2017

Composite Floor system infilled with PCM(Phase Change Material) between upper and lower steel plates was developed to apply the steel frame. When steel frames were applied this system, it can absolutely reduce the duration of construction due to dry construction method. However to apply this system as a structural floor member without fire resistance covering, it must have 2 hours fire resistance performance. Because PCM consisted of three quarters of section with thermal insulation performance, fire resistance performance of this floor system was expected to easily have 2 hours fire resistance performance. This paper was to investigate behavior characteristics of PCM infilled floor system at elevated temperature using FEM analysis to develop the fire resistance performance of it.

• KIEAE Journal
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• v.9 no.1
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• pp.107-113
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• 2009

The energy cost is resulted from the energy use. Its sources are divided into some types and depended on the building use or energy-use type. The energy cost should be affected by the amount of the energy use. The cost could be calculated to consider various factors such as the insulation, heating type, building shape and others. But it can not consider all of the affect factors to the energy cost and need to categorize the factors to the condition for estimating the cost. In this paper, it aimed at providing the estimation model in linear equation and multiple linear regression, utilizing the building exterior condition and management characteristics in apartment housing. Its survey are conducted in two parts of management characteristics and building exterior condition. The correlation analysis is conducted to get rid of the multicolinearity among the inputted factors. The number of linear equation model is 11 and includes the 1st, 2nd and 3rd equation function, power function and others. Among these, it suggested the 2nd and 3rd function and power function in terms of the statistics. In multiple linear regression model, the building volume and management area are inputted to the estimation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.49-55
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• 2003

This paper studied characteristics of surface discharge and tracking phenomena on the surface of solid insulators in Liquid Nitrogen(LN2) noticed as a cooling medium of high temperature superconductor. In order to investigate the bubble effect which have much influence on electric surface discharge in Liquid Nitrogen, knife type electrode and plane electrode were formed oppositely with A-mode, B-mode and C-mode configuration. 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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• summer
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• pp.1067-1069
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• 2004

22.9[kV]/50[MVA]/30[m] HTS transmission power cable has been developed and tested at Korea Electrotechnology Research Institute and LG Cable Company by 21 century center for applied superconductivity technology. It is necessary to measure of critical current degradations, AC loss, insulation test and etc at the HTS cable development. This paper is analyzed characteristics that critical current of HTS cable bending condition according to this paper. We will be able to decide the diameter of drum which HTS cable is wound around and minimum curvature radius of HTS cable from results of this research.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.146-154
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• 1998

Broadband noise with frequency components in the range from several kHz up the tens of MHz is a major obstacle factor in normal operation of the AC line to supply the power to electrical and electronic control equipments. Because this kind of noise could damage the device or could be a source of malfunction, many devices such as filter and surge suppressor are used to cut off the noise. But those devices could not disconnected from the power line, so they result in poor common-mode of NCT as well as insulation characteristics as a isolation transformer in addition faraday shielding and proposed analysis model of NCT having tow functions of surge and noise reduction. The simulated and experimental results for the surge suppression characteristics are compared and evaluated for designed protype 1[kVA] NCT.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.19-26
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• 2015

This paper presents design, fabrication, and performance evaluation of a high voltage power supply for Carbon Nano Tube-based planar light sources. The proposed power supply employs an LLC resonant half-bridge converter and a sixfold voltage-multiplying rectifier. Steady-state characteristics of the voltage-multiplying rectifier are analyzed and used to derive the input-to-output voltage conversion ratio of the power supply. The input-to-output frequency response characteristics of the LLC tank circuit are analyzed and utilized in designing a proto-type power supply which produces a 15 KV output using a 400 V input source. The high-voltage transformer is fabricated using a sectional bobbin structure with an epoxy impregnation, in order to provide sufficient insulation for high voltage operations. The performance of the proposed power supply is confirmed with stable and reliable operations at the 15 KV output from no load to nominal load conditions. The proposed power supply is well suited as an electric ballast required stable operations of Carbon Nano Tube-based planar light sources.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.270-273
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• 1994

The capacitive current breaking capability as well as the short circuit current breaking capability is a very important factor in the performance of a circuit breaker. The dielectric recovery capability between poles should be considered in the desist of a circuit breaker because approximately two times of the maximum power system voltage might be applied between poles after the capacitive current be interrupted. The electric field and flow field analyses were utilized in the calculation of dielectric recovery characteristics between poles of 800kV model interrupter. The results show that the separation between moving main contact and moving arcing contact will affect to decrease significantly the electric field strength of a moving arcing contact and an insulation cover, to increase slightly the electric field strength of a fixed arcing contact and to decrease consequently the dielectric recovery capability between poles of the interrupter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.779-782
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• 2000

Silicone rubbers are first silicone polymers and has named silicone from existence of Si-O bond similar to Keton. Silicon in organic compound has been called silicone, and linear or network polymers. Silicone rubbers have been used as an power insulator because they are well weather proof, ozone proof and have excellent electric characteristics, thermal stability, cold resistance and low surface energy. Especially, it is known that they have very excellent characteristics at 200[$^{\circ}C$]. For this study, we made silicone rubbers as specimens and we measured dielectric loss tangent due to applied voltage at temperature range 25[$^{\circ}C$] to 180[$^{\circ}C$] and frequency range 20[Hz] to 1${\times}$10$\^$6/[Hz] to examine dielectric properties. We measured dielectric loss tangent to study the insulation performance of silicone rubbers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.400-403
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• 2003

Recently, the study on development of electrical and electronic device is done to get miniature, high degrees of integration and efficiency by using inorganic materials. the study of Langmuir-Boldgett(LB) method that uses organic materials because of the limitation for the ultra small size. In this paper, detected displacement current using PBLG and PBDG, deposition and observed the electrical characteristics to each 1, 3, 5, 7, 9 layers by LB method. Maximum value of change ratio of displacement current by the detected speed and temperature appeared almost lineally, could confirm that it are in comparison relation each other speed temperature and displacement current. The structure of manufactured device is MIM. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from 0 to +2[V]. The insulation property of a thin film is better as the distance between electrodes is larger.