• 전기전자학회논문지
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• 제18권4호
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• pp.586-592
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• 2014

본 논문에서는 DT-CMOS(Dynamic Threshold voltage Complementary MOSFET) 스위칭 소자를 사용한 DC-DC Buck 컨버터를 제안하였다. 높은 효율을 얻기 위하여 PWM 제어방식을 사용하였으며, 낮은 온 저항을 갖는 DT-CMOS 스위치 소자를 설계하여 도통 손실을 감소시켰다. 제안한 Buck 컨버터는 밴드갭 기준 전압 회로, 삼각파 발생기, 오차 증폭기, 비교기, 보상 회로, PWM 제어 블록으로 구성되어 있다. 삼각파 발생기는 전원전압(3.3V)부터 접지까지 출력 진폭의 범위를 갖는 1.2MHz의 주파수를 생성하며, 비교기는 2단 증폭기로 설계되었다. 그리고 오차 증폭기는 70dB의 이득과 $64^{\circ}$의 위상여유를 갖도록 설계하였다. 또한 제안한 Buck 컨버터는 current-mode PWM 제어회로와 낮은 온 저항을 갖는 스위치를 사용하여 100mA의 출력 전류에서 최대 95%의 효율을 구현하였으며, 1mA 이하의 대기모드에도 높은 효율을 구현하기 위하여 LDO 레귤레이터를 설계하였으며, 또한 2개의 IC 보호 회로를 내장하여 신뢰성을 확보하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.11-12
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• 2009

In this paper, we propose a high voltage driver IC(HVIC) for LCD and PDP TV power supply. The proposed circuit is included novel a shoot-through protection and a pulse generation circuit for the high voltage driver IC. The proposed circuit has lower variation of dead time and pulse-width about a variation of a process and a supply voltage than a conventional circuit. Especially, the proposed circuit has more excellent pulse-width matching of set and reset signals than the conventional circuit. Also the proposed pulse generation circuit prevent from fault operations using a logic gate. Dead time and pulse-width of the proposed circuit are typical 250 ns, and its variation is maximum 170 ns(68 %) about a variation of a process and a supply voltage. The proposed circuit is designed using $1\;{\mu}m$ 650 V BCD process parameter, and a simulation is carried out using Spectre.

• 한국전기전자재료학회논문지
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• 제22권10호
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• pp.801-807
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• 2009

In this paper, we propose a novel shoot-through protection circuit and pulse generator for half-bridge driver IC. We designed a robust half-bridge driver IC over a variation of processes and power supplies. The proposed circuit is composed a delay circuit using a beta-multiplier reference. The proposed circuit has a lower variation rate of dead time and pulse-width over variation of processes and supply voltages than the conventional circuit. Especially, the proposed circuit has more excellent pulse-width matching of set and reset signals than the conventional circuit. Also, the proposed pulse generator is prevented from fault operations using a logic gate. Dead time and pulse-width of the proposed circuit are typical 250 ns, respectively. The variation ratio is 68%(170 ns) of maximum over variation of processes and supply voltages. The proposed circuit is designed using $1\;{\mu}m$ 650 V BCD (Bipolar, CMOS, DMOS) process parameter, and the simulations are carried out using Spectre simulator of Cadence corporation.

• 한국항행학회논문지
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• 제16권2호
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• pp.360-366
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• 2012

공항과 같은 산업 설비에 사용되는 분전반에서는 주 개폐기로 배선용 차단기가 사용이 되고 있으며, 분기 개폐기는 누전 차단기가 사용되어 인체 보호 및 누전 화재 보호 기능을 수행하고 있을 뿐만 아니라, 과전류 보호, 단락 보호 겸용 기능을 포함하여 사용되어 지고 있다. 특히 공항용 분전반의 경우 사용자의 급증과 함께 급속한 첨단화와 기기의 대용량화, 다양화, 전원용량의 증대 등으로 공항의 안정적인 전원 공급을 위하여 사고에 대한 보호 증대가 필요하게 되었고, 분기 누전 차단기의 다량 사용에 의한 2열 배열의 접속 방법 등으로 분전반을 제작하여 설치 면적에 대한 이슈가 부각되어 차단기의 슬림화가 주요한 문제로 자리 잡고 있다. 본 논문에서는 이를 위하여 아크 소호 기구부의 설계, 접점이 운동 방향 변경을 고려하여 기구부를 설계하고, 누전 검출 회로의 소형화 및 역 접속 시에도 안적적인 동작이 가능하도록 설계하였으며, 이를 검증하기 위하여 단락 시험을 실시함으로써 성능 검증을 하였고, 사고 전류에 대한 보호 기능의 강화와, 차단기의 슬림화, 역접속시에서 누전 동작이 가능한 차단기를 개발함으로써 급속히 커져가는 공항용 분전반에서 발생하는 공간 사용의 문제점을 해결하는데 도움을 주고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.786-789
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• 2002

The behaviour of contactors protected by arcs under short-circuit currents is analysed using a simple model to represent the electric circuit and the contactor. In most cases, the protection of contactors against short-circuit currents is entrusted to fuses. Fuses are suitable for preventing excessive damage to the contactor, or parts of the contactor, under short-circuit conditions. In particular, they are capable of limiting the thermal and electrodynamic stresses which can lead to arcing or welding together of the contacts of a contactor. This paper is the Dynamic Motion Analysis of a Moving Contact by Electromagnetic Repulsion Force in Molded Case Circuit Breaker(MCCB)

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.36-37
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• 2016

The main cause of electrical fires are caused due to short circuit and open circuit. This is generates an instantaneous electric arc or spark accompanied with such electric faults. These arcs generate a pressed wire, contact badness, and a weakness in the wire coating etc.. This research proposes a protection circuit to prevent open-phase accident due to contact failure of electromagnetic contactor, tracking arc fault, open-phase within the three-phase electrical control panel which is the most commonly applied in the industry. The proposed circuit also alarms and cuts off of power system when electrical faults occurs. In addition, the proposed circuit is validated by various electric accident simulator.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.704-711
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• 2000

This study is carried out using a circuit model approach. First, the self and shunt impedances of all the conductors in the rail system and the mutual impedances between different conductors are computed. Then, a circuit representing the both rail systems at interfaces including the rails, feeders, protection wires, contact wires, ground wires is built. Auto-transformers in the system are also represented in the circuit model. The circuit model is then 1]recessed using a circuit solver based on a double-elimination method. Several different scenarios are analyzed, including the load conditions and a few fault conditions with different fault locations. The effect of the buried ground wires is also analyzed by comparing the results with and without the presence of the ground wires. The analysis procedure presented in the paper demonstrated an accurate way of computing fault current distribution and EMC at interfaces between both systems. The results presented in the paper can be used as a reference for estimating interference levels in similar rail systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.916-917
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• 2008

In this paper, Switching damage of switches that is used to proposed power conversion system is reduced by soft switching way. dissipation by part resonance and my resonance stress for resonance of resonance circuit are decreased. Is acted by conversion system high effectiveness. Have following characteristic. Design snubber circuit that is used by switch protection in existent hard work rate Topology by resonant circuit for sogt switching, circuit structure was simple and control system is easy. Also, Can generate free output voltage by multi level Tuesday of output that use individuation Power Cell's Phase Shift PWM, and Low-end switching frequency the harmonic is few.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.930-931
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• 2008

This study is on the development of a low cost inverter module with Power Factor Correction(PFC) circuit which satisfies the international harmonic current standard such as IEC61000-3-2. In this study, the performances of the PFC circuit applying a new control method are simulated and verified by Matlab/Simulink. Also, the inverter module with the designed PFC circuit is implemented and the experimental results for the module are presented. Finally, through an analysis for the results of the simulation and the experiment, the merits obtainable by applying the PFC circuit when designing an inverter module are discussed and presented.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권11호
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• pp.550-556
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• 2001

The computerized cardiac analysis system, which acquires and analyzes the electrical activation signal propagating along the surface of the heart, is indispensible equipment for the open heart surgery and electrical cardiac study. In this paper, the design requirement and the electrical circuit analysis are performed to construct the multi-channel cardiac activation pre-amplifier necessary for a signal conditioning circuit. The general 64 channel configuration is expanded into 128 channels to enhance the spatial resolution on the mapped surface of the heart. The 128 channels pre-amplifier consists of input circuit, differential amplifier, right leg driven circuit and isolation part. It has distinct features; high voltage protection, leakage current limitation, isolation and the maximization of common mode rejection ratio with respect to the half-cell potential difference due to different electrode materials. The final pre-amplifier circuit is assembled with 8 boards, each of which composing of 16 channels.