• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.234-238
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• 1999

The correlation between shape of electrical trees and partial discharge(PD) pulses in low density polyethylene(LDPE) were discussed. We observed growth feature of electrical tree by using optical microscope. On the basis of experimental results of measurements of trees occurring in the needle-plane arrangement with needle shape void and without needle shape void , statistical quantities are derived, which are relevant to PD pulse amplitude and phase. The PD quantities detected by partial discharge detector. we were analyzed q-n distribution pattern and $\psi$ -q-n distribution pattern. In this experiment, electrical trees in the needle-plane arrangement with needle shape void propagated branch type tree and in the needle-plane arrangement without needle shape void propagated bush type tree

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1581-1583
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• 2000

In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible of backlight as a lighting source in LCDs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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• pp.66-71
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• 2016

In this study, electrical and spectroscopic characteristics were investigated in the pin to plate discharge of 0.9% weight per unit volume saline solution. The positive and positive- and negative-going dc pulse with 5% duty ratio were applied to tungsten pin electrode. The more amount of discharge current flew in negative discharge. The temperature, which is considered as a local value in the vicinity of vapor of discharge, was about 3,000K which is much higher than the value recommended to be controlled. It can be suggested that not only the temperature of liquid but also the local temperature of vapor is monitored to investigate damages on tissue or cells in biological application.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.828-832
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• 1995

This paper describes the efficient design, analysis method and experimental verification of capacitor discharge impulse magnetizer system. A capacitor discharge magnetizer system is used to produce a high current impulse of short duration in this magnetizing fixture. The parasitic resistance and parasitic inductance of the capacitor discharge impulse magnetizer system have been estimated using known air-core test coil. Finite element analysis (using MAXWELL 2-D field simulator) and magnetizing circuit analysis (using SPICE) are also used as part of the design and analysis process of the capacitor discharge impulse magnetizer system. Application study for a magnetizing fixture design is shown. 8-pole magnetizing fixture has been designed and analyzed using finite element analysis. The fixture design for 8-pole magnet are presented along with the experimental results. The experimental results have been achieved using a high-voltage, high-energy capacitor discharge impulse magnetizer and 8-pole iron core fixtures (charging voltage : 2000[V], capacitor bank : 4000[$\mu\textrm{F}$]).

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1908-1912
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• 2009

유량자료는 물의 순환과정을 규명하고 효율적인 수자원 개발 및 이수 치수 계획 등에 매우 귀중하게 이용된다. 그러나 이러한 유량자료를 확보하는 데는 많은 시간과 경비 등이 요구되기 때문에 주요 수위의 유량측정자료로 수위-유량관계 곡선식(Stage-Discharge Curve)을 개발하여 유량자료를 환산하고 있다. 따라서 수위-유량관계 곡선식의 신뢰도는 유량자료의 품질에 절대적인 영향을 미치는 요인으로 작용된다. 수문학을 연구하는 많은 학자들은 고품질의 유량자료를 생산하여 신뢰성 있는 곡선식을 개발하고자 유량측정 방법과 기준, 장비개량 등에 관한 연구를 수행하고 있다. 측정하고자 하는 기기별 측정 성과에 대한 연구 자료가 거의 없이 국내에 보급된 다양한 유속측정기기를 사용하여 유량자료를 생산하여 활용하고 있다. 본 연구에서는 규격화된 콘크리트 수로에 일정한 유량을 흘려보내고 다양한 측정기기를 이용하여 유속을 측정하였다. 그리고 이 측정성과를 이용하여 유량을 산정하고 비교분석하였다. 실험을 위해서 국내에서 일반적으로 사용되고 있는 측정기기로 마그네틱유속계(Electromagnetic Current Meter), 휴대용유량계(Flow Meter), 프라이스유속계(USGS Type AA Current Meter), 갈수기용유속계(USGS Pygmy Meter)등의 장비를 사용하였으며, 동일한 조건에서 유량을 얻음으로 측정 기기가 제시하는 유량을 알 수 있었다. 비교검토에 적용하고자 측정한 수심으로는 0.25m, 0.30m, 0.35m, 0.40m의 4개 Case로 진행이 되었으며, 측정방법으로는 도섭법(Wading Measurement)에 의하거나 케이블웨이(Cableway), 교량법(Bridge Measurement), 보트법(Boat Measurement)등이 있으나, 신뢰성과 정확도를 높이기 위해 도섭법으로 수면에서 0.6d 지점의 유량측정방법(1점법)을 적용하였다. USGS Type AA Current Meter, USGS Pygmy Meter는 유속측정기기의 검교정을 받았으므로 다른 실험유속측정치의 비교를 위한 기준값으로 사용하였다. 따라서 국내에서 널리 사용되는 측정기기(Electromagnetic Current meter, Flow Meter, USGS Type AA Current Meter, USGS Pygmy Meter)별 검토 결과 프라이스유속계를 기준으로 마그네틱유속계는 ${\pm}$10% 이상, 갈수기용 유속계 및 휴대용 유량계는 ${\pm}$5% 미만의 차이가 있음을 확인할 수 있었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.45-51
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• 2008

HID(High Intensity Discharge) search lamp for shipment requires a high open circuit and output current compare than vehicle. This paper presents a soft-start open circuit voltage and constant current sequence control method for 2.5[kW] HID search lamp. The proposed method controls the opal circuit voltage and discharge current of HID lamp according to ignition signal with a simple 8-bit micro-processor and PWM device. For the stable control of lamp, micro-processor checks the output voltage and current. And the checked signals are compared with ignition signal and changes the control mode for stable operation. An ignition signal and micro-processor change the control mode from open circuit voltage contort to constant current control. The proposed control scheme is verified from experimental tests of 2.5[kW] HID search lamp for shipment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.169-172
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• 2004

We present the basic properties of a superconducting current limiting fuse (SCLF) based on YBCO/Au films. The SCLFs consists of YBCO stripes covered with Au layers for current shunt. Under the source voltage of 100 $V_{rms}$, the longer the duration time of fault current was, the shorter its discharge time was. The duration time of fault current and its discharge time were reduced by increased voltages in the range of 200 - 300 $V_{rms}$. We thought that this was because the quench propagation was limited by local melting generated with higher voltage.

• Membrane Journal
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• v.22 no.3
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• pp.208-215
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• 2012

Gel polymer electrolyte membranes were prepared from blends of polyvinyl alcohol (PVA) and poly (acrylic acid) (PAA), by solution-cast technique. The PAA content in the blend varied from 30 to 80 wt%. With the gel polymer electrolyte membranes, Zn air batteries were fabricated. The gel polymer electrolyte membranes were characterized by means of stress-strain test, impedance test. The Zn air batteries were tested by current interrupt method and galvanostatic discharge method. The tensile strength and tensile modulus decreased with increasing PAA content in the gel polymer electrolyte membrane. On the other hand, the ionic conductivity increased with increasing PAA content. The effect of ionic conductivity trend of the gel polymer electrolyte membrane in the Zn air battery was confirmed through current interrupt method and galvanostatic discharge method experiments. The battery with higher PAA content gel polymer electrolyte membrane showed lower IR drop and higher discharge capacity.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.69-75
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• 2013

To increase the efficiency of the photovoltaic, almost photovoltaic appliances are controlled by Maximum Power Point Tracking(MPPT). Existing most of the PV MPPT techniques have used power which multiplies sensed output current and voltage of the solar cell. However, these algorithms are unnecessarily complicated and too expensive for small and compact system. The other hand, the proposed MPPT technique is only one sensing of the MPPT converter's output current, so there is no need to insert another sensors of battery side. Therefore, this algorithm is simpler compared to the traditional approach and is suitable for low power solar system. Further, the novel proper charge/discharge algorithm for the battery with PV MPPT is developed. In this algorithm, there is CC battery charge mode and load discharge mode of the PV cell & battery dual. Also we design current control to regulate allowable current during the battery charging. The proposed algorithm will be applicable to battery included solar cell applications like solar lantern and solar remote control car. Finally, the proposed method has been verified with computer simulation.

• Journal of Biosystems Engineering
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• v.22 no.3
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• pp.303-310
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• 1997

Motivated by the need fir developing the new method of weed control in place of chemical weedicide, this paper aims at making good use of electricity against environmental pollution. Compared with chemical weedicide, the electric method of weed control is functionally more versatile, effectively more rapid, and lower in terms of cost. In particular, this method will contribute to environmental protection. In detail the electrical weed control system which is the simple circuit for generating the electric current of high voltage is comprised of step-up transformer which rectifies the current and the capacitor which stores the energy. The effectiveness of electrical weed control system is evaluated by germination rate and control of Dgitaria Sangvinalis(Galinsoga ciliate). As a result, the electrical weed control system(high voltage spark discharge) can kill weeds effectively