• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.215-216
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• 2005

To decrease and remove of much noises that is detected in PD (partial discharge) measuring test. we forced on detection of those. We made W-LC filter for measuring PD. which adapted that to field test. We tested after design laboratory circumstances like field line. and then the phase change properties of detected signal in UHF sensor were measured by Lemke Probe and oscilloscope (TDS-3054. Tektronix). Eventually we checked decrement of noises from experimental result. Also from experimental result at the joint box of 22.9[kV] distribution line. we obtained reasonable data which enable noises to decrease. Hereafter those results will be adapted at ultra-high voltage for trouble prevention and on-line cable watch. diagnosis of those.

• 조명전기설비학회논문지
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• 제22권1호
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• pp.157-164
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• 2008

본 논문에서는 모의 GIS 내부에 도전성 파티클을 놓아둠으로써 전하의 축적과 전계의 집중이 용이하도록 하여 부분방전을 모의하였다. 이때 부분방전 발생과 진전에 따른 방사전자파를 스펙트럼 분석기와 EMI.EMC 측정용 안테나($30{\sim}2000[MHz]$)를 사용하여 측정 분석하였다. 모의 GIS 내부에 도전성 파티클 존재에 따른 부분방전의 검출과 방진전전 과정의 판단을 위한 절연진단의 방법으로써 본 논문에서 제안한 측정 주파수의 대역의 분리와 데이터 측정과 분석법을 이용하면 부분방전의 검출과 방전과정의 판단이 가능함을 확인하였다.

• 조명전기설비학회논문지
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• 제29권10호
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• pp.97-103
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• 2015

This paper presents the characteristics of partial discharge and radiated electromagnetic waves in the existence of a poor contact for the insulation diagnosis of eco-friendly power equipment. AC surface discharge experiment was conducted to simulate the poor contact between a hive voltage electrode (anode) and a solid insulator in $N_2/O_2$ mixture gas under a non-uniform field. The partial discharge voltage to be measured at 0.3MPa increased with the increase of the poor contact gap and was saturated with the gap. In addition to the partial discharge characteristics, it was verified that the defect of the poor contact can be diagnosed using the radiated electromagnetic waves due to the partial discharge, which measured by a biconical EMC antenna and a spectrum analyzer.

• 전기학회논문지
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• 제65권8호
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• pp.1436-1441
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• 2016

Currently, partial discharge diagnosis in the field of prevention applied technology and diagnostic equipment is a possible strong limit to remove the noise generated by external or internal I still have one unreliable diagnosis. This technology is the noise removal from signal the time lag analysis algorithms technique is applied by a fundamental. Increasing the reliability in terms of technology spectrum frequence of analysis method for by applying the acquisition through the position of the frequency content and sources of traffic lights partial discharge of the acquisition of signal analysis to judge whether a way diagnosis the environment of the scene, and conditions. Partial discharge signal and make the discharge while building blocks were found through the Analysis. Spectrum frequence of Analysis and wide discharge part, to be more precise, in line with the various functions, including the analysis technique band. Diagnosis and comes up with advanced technology that can detect the presence of a position. This method is portable single device developed for maintenance and mobility and ease and convenience of getting caught by discharge of the pattern analysis and position detection method suitable for a new diagnosis will suggest.

• 대한관절경학회지
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• 제4권1호
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• pp.71-75
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• 2000

목적 : 내측 반월상 연골의 양동이형 파열에 대한 기존의 보편적인 치료법인 전방 도달법을 이용한 관절경적 부분 절제술에 비해 보다 우수한 후내측 도달법을 이용한 관절경적 부분 절세술을 소개하고자 한다. 방법 : 슬관절의 관절경적 기본 검사 후 파열된 반월상 연골의 정복을 시행한 수, 관절경을 후내측 구획에 위치시킨 후, 관절경적 시야 하에서 후내측 도달법을 개설하여 관절경을 삽입하여 이 구역을 재관찰하며, 관절경적 부분 절제술을 시행한다. 결론 : 내측 반월상 연골의 양동이형 파열에 대한 기존의 전방 도달법을 이용한 관절경적 부분 절제술은 내측 반월상 연골의 후각 부착 부위에 대한 시야확보가 부족하여 정확한 부분 절제술이 될 수 없고, 후각부에 동반된 다른 유형의 파열이나 내측 대퇴 내과 후면의 관절 손상 등을 관찰할 수 없고, 술 중 후방 십자인대에 손상을 줄 수가 있으며, 내측 대퇴골과의 체중부하 부위에 인위적인 관절 연골 손상을 줄 수가 있다. 후내측 도달법을 이용한 내측 반월상 연골의 양동이형 파열에 대한 관절경적 부분 절제술은 우수한 방법이라 생각된다.

• 한국작물학회지
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• 제52권3호
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• pp.259-263
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• 2007

최근 맥류 파종기의 잦은 강우로 파종이 늦어지는 경우가 많은데 기존의 파종방법으로는 습한 포장에서의 파종이 쉽지 않아 만파의 유인 중 하나가 되고 있다. 이에 따라 과습 상태의 토양에서도 논에서 맥류의 파종이 가능한 새로운 파종 법의 개발이 필요하다. '99년에 벼 파종용으로 개발된 부분 경운 건답 직파기를 이용하여 논에서 맥류를 파종할 때의 생육 및 수량에 대해 $2001{\sim}2003$년에 걸쳐 시험하였다. 가. 배수 후 $1{\sim}3$일, 즉 토양수분이 각각 50% 이상, 40%, $27{\sim}30%$를 보이는 토양에서 휴립 광산파와 세조파의 경우는 정상적인 파종이 불가능하였으나 부분경운 파종기를 사용하여 파종한 경우 토양수분 40%(배수 후 2일)만 되어도 정상적인 작업이 이루어져 파종이 가능하였고 초기 생육도 양호하였다. 반면 세조파종법과 휴립광산파는 토양수분 40%에서 뿐만 아니라 토양수분이 27%로 낮아져도 작업기주변에 흙이 범벅이 되어 종자가 흙과 함께 쓸려가 제 위치에 종자가 놓이지 못하였다. 이로 인해 파종법사이의 보리 입모 차이가 확연하였다. 나, 토양수분 함량 30-40%(배수후 2일)에 파종된 부분 경운파종구의 생육을 세조파종구와 비교해 볼 때 부분경운 파종기 구의 입모수가 충분히 확보되었고 이로 인해 수수도 충분히 확보되어 같은 수분함량에서 파종된 휴립광산파와 세조파에 비해 높은 수량을 보였다. 벼를 위해 개발된 부분경운파종법은 토양 과습시 보리의 파종작업에 유리한 점이 많아 농가에 보급되어 벼, 보리 모두에 이용 가능할 것으로 판단되었다. 다. 부분경운파종기에 부착된 배토기의 배수로 폭이 14cm로 좁고 깊이도 일반배토기에 비해 얕아 배수로 역할을 제대로 하지 못하였으므로 파종 후 과습이 계속될 경우에는 추가적인 배수로 보완 또는 작성 작업이 필요하며 잡초도 일반 포장에 비해 많이 발생할 우려가 있음이 보고되고 있어 적기에 잡초방제를 해야 할 것이다.

• 한국자기공명학회논문지
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• 제24권3호
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• pp.66-69
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• 2020

In ultra-low field magnetic resonance imaging (ULF-MRI), the strength of a static magnetic field can be comparable to that of gradient field. On that occasion, the gradient field is accompanied by concomitant gradient field, which yields distortion and blurring artifacts on MR images. Here, we focused on the distortion artifact and derived the equations capable of correcting it. Its usefulness was confirmed through the corrections in both simulated and experimental images. This solution will be effective for acquiring more accurate images in low and/or ultra-low magnetic fields.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권10호
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• pp.492-499
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• 2002

This paper presents the method for an estimation of discharge current waveform in short gap discharge by radiated electromagnetic fields. The method of current waveform estimation is to use the one antenna method (single field method) with a measured electric or magnetic field at given field point by a time domain antenna. In order to verify the availability of the estimation theory, the discharge current waveform estimation was performed by one antenna methods using the measured electric fields of Wilson & Ma and compared with experiments. In addition diagnosis technique for power equipments is able to prevent from large accidents by finding signs of tile accidents before they happen. From the results of the estimation of discharge current, we have a possibility for the application of insulation diagnosis technique for power equipments using S$F_6$ gas. From this point of view, this paper simulated discharge progress and partial discharge by using needle-plan electrodes system in S$F_6$, studied the distribution of frequency spectrum of the radiated electromagnetic waves using a biconical antenna and a spectrum analyzer. From the experimental results of this study, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting Partial discharge and estimating discharge progress in S$F_6$ could be Possible.

• Transactions on Electrical and Electronic Materials
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• 제3권3호
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• pp.34-38
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• 2002

In this paper, efficiency estimation of toxicity fee fire resistance cable experiments was measured smoke density of toxicity free fire resistance polyolefin insulation material and electric field dependence of tree shape in low density polyethylene (LDPE). One of the most serious causes of failure in high-voltage cables, can be an electrical discharge across an internal gab or void in the insulating material. Treeing due to partial discharge is one of the main causes of breakdown in the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation and research of the fire resistance character has become important. First, we have studied on electric field dependence of tree shape in LDPE about treeing phenomena occurring on the high electrical field. Second, the measurement method is the attenuation quantity of irradiation by smoke accumulating with in a closed chamber due to non-flaming heat decomposition and flaming combustion. A main cause of fire-growth and generating toxic gas when, it bums, should be dealt with great care in life. safety design. The fire gases were occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC, which has high content of carbon in chemical compound.

• Advances in Energy Research
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• 제1권2호
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• pp.97-106
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• 2013

This study designs and tests a photovoltaic system with distributed maximum power point tracking (DMPPT) methodology using a field programmable gate array (FPGA) controller. Each solar panel in the distributed PV system is equipped with a newly designed DC/DC converter and the panel's voltage output is regulated by a FPGA controller using PI control. Power from each solar panel on the system is optimized by another controller where the quadratic maximization MPPT algorithm is used to ensure the panel's output power is always maximized. Experiments are carried out at atmospheric insolation with partial shading conditions using 4 amorphous silicon thin film solar panels of 2 different grades fabricated by Chi-Mei Energy. It is found that distributed MPPT requires only 100ms to find the maximum power point of the system. Compared with the traditional centralized PV (CPV) system, the distributed PV (DPV) system harvests more than 4% of solar energy in atmospheric weather condition, and 22% in average under 19% partial shading of one solar panel in the system. Test results for a 1.84 kW rated system composed by 8 poly-Si PV panels using another DC/DC converter design also confirm that the proposed system can be easily implemented into a larger PV power system. Additionally, the use of NI sbRIO-9642 FPGA-based controller is capable of controlling over 16 sets of PV modules, and a number of controllers can cooperate via the network if needed.