• 한국안전학회지
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• 제33권5호
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• pp.21-27
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• 2018

The purpose of this study is to develop a SOP (Standard Operating Procedure) for a distribution board that can monitor the leakage current of a load distribution line in real time. The developed distribution board was fabricated by applying IEC 61439-1. It consists of the distribution board and an alarm device. The work process for making the distribution board was compliant with the KEMC (Korea Electrical Manufacturers Cooperative) regulations. And the AC distribution board range is 1,000 V. In addition, the voltage in DC is less than 1500 V. The distribution board receives a 3-phases and 4-wires power supply system and can supply power to the load of a maximum of 32 single or three phase distribution circuits. Also, leakage current measured on the power distribution board was used by sensors installed. The SOP of the developed distribution board consists of the installation standards for the short circuit alarm device and sensor, the surge protection device, switches and indication lamps, and other devices. The operation procedure was prepared so that each manufacturing step of the distribution board must be confirmed by the persons in charge of preparation, production, quality control and approval before moving forward to the next step.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.109-110
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• 2014

신재생에너지의 신뢰성 및 효율의 발전과 함께 컴퓨터 및 각종 디지털 부하의 증가로 인하여, 효과적인 DC 에너지 공급 시스템을 위한 연구가 진행되고 있다. 그중 DC 전원의 경우, 아크 발생과 누설전류 검출이 중요한 문제가 된다. 본 연구에서는 반도체 소자를 사용하여 아크가 발생하지 않게 하는 콘센트에, 누설 감지 감도는 8mA, 감지 시간은 120ms 이내의 누설 전류 검출 기능을 보강한 DC 콘센트를 제안한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권8호
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• pp.392-401
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• 2001

This paper presents the single-stage high power factor AC to DC converter operated in active-clamp mode. The proposed converter is added active-clamping circuit to boost-flyback single-stage power factor corrected power supply. The active-clamping circuit limits voltage spikes, recycles the energy trapped in the leakage inductance, and provides a mechanism for achieving soft switching of the electronic switches to reduce the switching loss. The auxiliary switch of active-clamping circuit uses the same control and driver circuit as the main switch to reduce the additional cost and size. To verify the performance of the proposed converter, a 100W converter has been designed. The proposed converter gives good power factor correction, low line current harmonic distortions, and tight output voltage regulation, as used unity power factor.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.623-628
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• 2009

There is an increasing demand for efficient high power/weight auxiliary power supplies for use on high speed traction application. Many new conversion techniques have been proposed to reduce the voltage and current stress of switching components, and the switching losses in the traditional pulse width modulation(PWM) converter. Especially, the phase shift full bridge zero voltage switching PWM techniques are thought most desirable for many applications because this topology permits all switching devices to operate under zero voltage switching(ZVS) by using circuit parasitic components such as leakage inductance of high frequency transformer and power device junction capacitance. The proposed topology is found to have higher efficiency than conventional soft-switching converter. Also it is easily applicable to phase shift full bridge converter by applying an energy recovery snubber consisted of fast recovery diodes and capacitors.

• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.44-48
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• 2013

Niobium oxide($Nb_2O_5$) films were deposited on p-type Si wafers at room temperature using in-line pulsed-DC magnetron sputtering system with various frequencies. The different duty ratios were obtained by varying the frequency of pulsed DC power from 100 to 300 kHz at the fixed reverse time of $1.5{\mu}s$. From the thickness of the sputtered $NbO_x$ films, it was possible to obtain much higher deposition rate in case of pulsed-DC sputtering than RF sputtering. However, the similar leakage currents and structural characteristics were obtained from the metal-insulator-semiconductor(MIS) structure fabricated with the $NbO_x$ films and the x-ray photoelectron spectroscopy(XPS) results in spite of the different deposition rates. From the experimental results, the $NbO_x$ films sputtered by pulsed-DC sputtering are expected to be used in the fabrication process instead of RF sputtering.

• Journal of Power Electronics
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• 제19권6호
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• pp.1366-1379
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• 2019

High-gain DC/DC converters have become one of the key technologies for the grid-connected operation of new energy power generation, and its research provides a significant impetus for the rapid development of new energy power generation. Inspired by the transformer effect and the ripple-suppressed ability of a coupled inductor, a double-coupled inductor high gain DC/DC converter with a ripple absorption circuit is proposed in this paper. By integrating the diode-capacitor voltage multiplying unit into the quadratic Boost converter and assembling the independent inductor into the magnetic core of structure coupled inductors, the adjustable range of the voltage gain can be effectively extended and the limit on duty ratio can be avoided. In addition, the volume of the magnetic element can be reduced. Very small ripples of input current can be obtained by the ripple absorption circuit, which is composed of an auxiliary inductor and a capacitor. The leakage inductance loss can be recovered to the load in a switching period, and the switching-off voltage spikes caused by leakage inductance can be suppressed by absorption in the diode-capacitor voltage multiplying unit. On the basis of the theoretical analysis, the feasibility of the proposed converter is verified by test results obtained by simulations and an experimental prototype.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.326-327
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• 2006

The paper describes the development of arrester for 154kV class power station and substation. The arrester employs silicone insulating materials for Its housing, instead of the conventional porcelain housing. The sealing integrity is related to safe operation of surge arrester, the prime failure reason of porcelain housed arresters is moisture ingress. In this paper, the sealing integrity of polymeric surge arresters for ultra high voltage is investigated with moisture ingress test. The diagnostic techniques are discusses, including watt loss, partial discharge, AC leakage current, 1mA DC voltage and residual voltage.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.225-228
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• 2001

We simulated and analyzed the flicker phenomena in the poly-Si TFT-LCD using PSpice for the development of wide-area and high-quality LCD display We define the electric quantity of flicker in the TFT-LCD, which is the ratio of half frame frequency (30Hz) to DC (0 Hz) frequency. We compared two different types of TFTs, excimer laser annealed (ELA) poly-Si TFT and silicide mediated crystallization (SMC) poly-Si TFT, and found that the ELA and SMC TFTs show different flicker characteristics because of their mobility and leakage current. In addition, we showed that the gate voltage should be chosen carefully at the minimum flicker because of the larger leakage current of poly-Si Tn as compared with a-Si TFT

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.333-336
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• 2003

태양광발전 및 소단위 풍력발전에 사용할 수 있는 변압기 없는 인버터를 설계하였다. 멀티 스위칭 방법에 의한 승압쵸퍼회로와 단상 풀브리지 인버터로 구성하였으며 소형화, 저 비용화를 위하여 변압기 없는 방식으로 설계하였다. 변압기 없는 시스템에서 문제가 될 수 있는 접지누설전류의 저감을 위해서는 스압쵸퍼의 스위칭기법 및 인버터 스위칭 등을 통하여 해결하였다.

• 한국정보통신학회논문지
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• 제8권2호
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• pp.407-412
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• 2004

태양광발전 및 소단위 풍력발전에 사용할 수 있는 변압기 없는 인버터를 설계하였다. 멀티 스위칭 방법에 의한 승압쵸퍼회로와 단상 풀브리지 인버터로 구성하였으며 소형화, 저 비용화를 위하여 변압기 없는 방식으로 설계하였다. 변압기 없는 시스템에서 문제가 될 수 있는 접지누설전류의 저감을 위해서는 승압쵸퍼의 스위칭기법 및 인버터 스위칭 등을 통하여 해결하였다