• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.44-52
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• 2014

The main purpose of this paper is to develop the new BIPV module equipped with vacuum glass. Beacuse BIPV module has a function of architectural materials, thermal and PV performance should be simultaneously evaluated. To improve the thermal performance of BIPV module, this study developed BIPV module equipped with a vacuum glass. Those BIPV module was tested with a variety of encapsulants. The results are as follows. When a vacuum glass is laminated with EVA or PVB, it was broken. The reason seems to be bending by unbalance of heat expansion with center and edge of vacuum glass. In case of lamination with resin, there is no breakage and no bending of vacuum glass. Because production was conducted in low pressure & low temperature conditions. And it was also found that vacuum glass does not interfere with the UV curing process.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1658-1660
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• 2004

Use of higher voltage and higher capacity of power systems and their equipment is leading to an increase in the size of the entire system. In order to reduce the cost of constructing a substation, it is necessary to reduce the size of equipment. So, this paper described optical sensor, which exploited the electric and magnetic potentiometer to sense the measured voltage and current of medium voltage GIS. It can be used both in measurement and in protection relays as its well linearity, rapid response, broad dynamic range, wide frequency band, no magnetic saturation, small in volume, light weight, and saft in insulation.

• Transactions on Electrical and Electronic Materials
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• v.7 no.5
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• pp.235-239
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• 2006

Charge dynamics in polymeric materials after aged under ac electric field using the pulsed electroacoustic (PEA) technique is reported. The emphasis is placed on charge decay. The charge dynamics of the ac aged additive free low density polyethylene (LDPE) samples under dc bias differ from the sample without ac ageing, indicating changes brought in by ac ageing. It is believed that a slow decay rate of charge in the ac aged sample is related to the formation of deep traps in the material. However, chemical analysis by infrared spectroscope (FTIR) and Raman microscope reveals no significant chemical changes taken place in the bulk of the material after ac ageing. Further experiments on irradiated LDPE have revealed a similar behaviour, i.e. the charge decay is slower in irradiated samples than that of fresh sample. The findings presented clearly indicate that space charge measurement can be used as a diagnostic tool to monitor ageing in polymeric materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.228-228
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• 2009

In stator windings of a 6.6kV rotating machine, internal discharge, corona discharge, and surface discharge are mainly caused by internal voids and insulation degradation. In the case of the discharge spark and electromagnetic pulse generated from a discharge source, we can detect it using various RF resonators like an EM sensor. In order to detect these types of electromagnetic sources, we designed and fabricated a planar patch sensor using a CST-MWS simulation, and PD signals from artificial defected stator windings were also measured by the sensor proposed in this study. Furthermore, In the results of the experiment, it showed similar performance to the HFCT sensor.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.166-169
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• 1990

The purpose of the circuit breaker on power system is to disconnect the faulty part from the system and to maintain the integrity of the system. With switching overvoltages are generated. When the system voltages become higher, switching overvoltage is important factor in insulation co-ordination. Since the no-load reclosing overvoltage with inductive source is severe, this paper deals with the reclosing overvoltage and the effect of closing resistor. This reclosing overvoltage of 27-bus model system with and without closing resistor is analyzed by using EMTP (Electro-Magnetic Transients Program) for both deterministic and Stochastic model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.79-82
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• 2005

This study aims to propose fundamental data for development of noise reduction system that is applied to classification for light-weight impact sound. For this reason, eight types of damping materials were constructed in new construction field. Comparison and analysis among the reduction materials were carried out on the acoustical characteristics through test. In the end, the suitability as a damping material was evaluated by the analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.813-816
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• 2003

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, according to Weibull distribution analysis, reducing breakdown probability of equipment insulation lower than 0.1 % level requires the allowable field intensity values to be kept under 21.5 MV/cm.

• 전기의세계
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• v.29 no.11
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• pp.727-732
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• 1980

The main purpose of this paper is to study on the effect of contact state between metal-polymer interface in electrical conduction of polymeric materials under low field region. The electric conduction of polythylene (PE) sandwitched in between two gold (Au) electrodes was lower than that of PE Sandwitched in between two Aluminium (Al) electrodes under low external field. The discharge current of PE which have been treated by the high field application is also obtained some results under no external field. The obtained results can suggest that the material of electrode come to influence on the electrical conduction of polymeric materials and are important as a basis for analysing the data on TSC. It is also suggestive that results of observation must be considered in cases of insulation design of electrical machinery.

• Progress in Superconductivity and Cryogenics
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• v.2 no.1
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• pp.7-13
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• 2000

A rotating cryogenic system was designed similar to the cooling system for the rotor of a superconducting generator. The experimental rotor has an inner vessel which simulates the winding space of an actual superconducting rotor, and a torque tube of comparable design. This paper describes the evaluation of the total heat leak into the inner vessel that leads to the study of the heat transfer characteristic of the rotating cryogenic system. To examine the insulation performance of the experimental rotor. temperature was measured at each part of the system at various rotaing speeds from 0 rpm to 600 rpm. Total heat leak into the inner vessel was calculated by measuring the boil-off rate of liquid helium. Conduction heat leak to the inner vessel was obtained by the vent tube, and radiation heat leak was calculated by subtracting the conduction heat lent from the total heat leak. There seemed to be no rotaional dependency of total heat leak at least up 600 rpm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.201-203
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• 2011

The purpose of this study was to develop and evaluate of fire resistive cladding systems for HSC(high-strength concrete) column, which was mainly constructed with aerogel blanket insulation material. The aerogel blanket-fire protective gypsum board cladding system showed that it clearly secure the fire resistance performance of HSC column when the reinforcing measures had achieved for four cross-sectional edge sides of structure and the system is well continued during the test period with no significant deformation or separation etc. It was checked out the 20mm thickness cladding system consist with AG(5mm)+FGB(15mm) can secure 3hour-fire resistance performance adequately.