• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.619-621
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• 1996

This paper presents the study on the development of the power factor correction convener with ZVT Boost converter, which is better than the conventional PWM Boost converter to increase the switching frequency for high density and lower stress of switch. A simple DC and small signal model for the power factor correction converter with constant switching frequency is derived. The guide line for design of controller is summarized.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.432-435
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• 1997

This Paper proposes a novel sinusoidal converter which improves input power factor and input current waveform without any complicated switching modulation such as a pulse width modulation or a complicated feed-back control. It is composed of a full bridge diode, a pair of capacitors, a pair of inductors and a pair of switching devices. The configuration and control strategy are both simple however, the sinusoidal converter effectively reduces reactive power and hamonics included in a input line current. Excellent behavior of the proposed converter is verified by theoretical analysis and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.391-393
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• 2008

This paper is analysed by switching overvoltage on operating reclosing in 154 [kV] combined transmission systems. Combined transmission systems are modeled by EMTP/ATPDraw program. It is fault condition that simulate high resistance earth fault. The simulation is carried out considering variation of parameters such as resistance value of fault point and rate of underground line.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.342-345
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• 1999

This paper describes a current regulated PWM boost type rectifier based on modified trapezoidal PWM. Each switch of a converter has no switching for one third period of a fundamental line current. Therefore, the switching loss of the proposed scheme is less than that of the hysteresis current controller. Operating principle is described and controller. Operating principle is described and simulations and experiments are carried out.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.337-341
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• 1989

This theory has fast response and low overshoot by transforming its structure and this system may have new character which did not appear in this system. The VSS system transform its structure by switching logic. Then, the state trajectory is to sliding along the switching line to the phase-plane orgin. The phase trajectory is known as the sliding mode of this controller. This paper performed position control in the theory and analysised the change in variable loads.

• 조명전기설비학회논문지
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• 제23권10호
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• pp.29-35
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• 2009

본 논문에서는 두 가지 전압을 이용하여 직류 전력선을 이용한 양방향 다중직렬통신 드라이버의 구현과 이를 위한 소형화 회로 설계에 대하여 다룬다. 다중접속통신은 호스트에 고유의 ID를 갖는 여러 개의 클라이언트와 패킷에 의한 데이터 전송을 행한다. 양방향 통신을 위하여 호스트에서 데이터 1/0이 전송될 경우, 각 경우에 24[V]/12[V]전원을 선택하며 클라이언트가 데이터를 전송할 때, 호스트는 통신선로의 전압을 감지하여 전송하는 데이터에 따라, 24[V]/12[V]전원을 선택한다. 이러한 기능을 구현하는 소형 드라이버 회로를 설계, 제작하여 호스트와 클라이언트의 직렬 통신 포트에 접속하였으며, 하나의 호스트와 여러 개의 클라이언트로 네트워크을 구현하고 실험에 의하여 직류 전력선을 이용한 양방향 직렬통신의 기능을 확인하였다.

• Journal of Power Electronics
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• 제16권3호
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• pp.1087-1096
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• 2016

This paper reports an investigation conducted on two diagnostic methods based on the switching voltage pattern of IGBT open-circuit faults in voltage-source inverters (VSIs). One method was based on the bridge arm pole voltage, and the other was based on bridge arm line voltage. With an additional simple circuit, these two diagnostic methods detected and effectively identified single and multiple open-circuit faults of inverter IGBTs. A comparison of the times for the diagnosis and anti-interference features between these two methods is presented. The diagnostic time of both methods was less than 280ns in the best case. The diagnostic time for the method based on the bridge arm pole voltage was less than that of the method based on the bridge arm line voltage and was 1/2 of the fundamental period in the worst case. An experimental study was carried out to show the effectiveness of and the differences between these two methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.125-128
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• 2006

This paper presents a novel type soft switching PWM power frequency AC-AC converter using bidirectional active switches or single phase utility frequency AC-high frequency AC matrix converter. This converter can directly convert utility frequency AC (UFAC, 50Hz/60Hz) power to high frequency AC (HFAC) power ranging more than 20kHz up to 100kHz. A novel soft switching PWM prototype of high frequency multi-resonant PWM controlled UFAC-HFAC matrix converter using antiparallel one-chip reverse blocking IGBTs manufactured by IXYS corp. is based on the soft switching resonance with asymmetrical duty cycle PWM strategy. This single phase UFAC-HFAC matrix converter has some remarkable features as electrolytic capacitor DC busline linkless topology, unity power factor correction and sine-wave line current shaping, simple configuration with minimum circuit components, high efficiency and downsizing. This series load resonant UFAC-HFAC matrix converter, incorporating bidirectional active power switches is developed and implemented for high efficiency consumer induction heated food cooking appliances in home uses and business-uses. Its operating performances as soft switching operating ranges and high frequency effective power regulation characteristics are illustrated and discussed on the basis of simulation and experimental results.

• 조명전기설비학회논문지
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• 제27권5호
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• pp.74-80
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• 2013

This paper presents the transient behavior of the switching surge voltages generated by interruption of DC ground fault currents flowing through metal flexible conduits. All fault circuits consist of line parameters such as resistance, inductance, capacitance and conductance. The use of nonmagnetic metal conduits should be taken into account in order to reduce the inductance of battery charger distribution circuits. The frequency-dependent circuit parameters of metal flexible conduits were measured. The switching surge voltages generated at the ground fault circuit consisted of steel-galvanized alloy and aluminium conduits were investigated. As a result, the impedances of metal flexible conduits are significantly increased over the range of the frequency above 10 kHz and the switching surge voltages generated along aluminium flexible conduit are lower than those along steel-galvanized alloy conduit when DC fault current is interrupted.

• 한국컴퓨터정보학회논문지
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• 제10권3호
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• pp.339-344
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• 2005

현재 오프라인 신용카드 가맹점에서의 신용카드 결제 시에 사용되는 결제 시스템은 신용카드 결제 단말기, 결제 중계 서비스를 하는 VAN사 그리고 신용카드사로 구성되어 있다. 신용카드사 장애 시에는 결제 중계 서비스 VAN사가 승인 대행을 하여 처리하나, 결제 중계 서비스 VAN사 장애 시에는 신용카드 결제 서비스가 원활하게 이루어지지 않는다. 본 논문은 신용카드 결제 단말기에 결제 중계 서비스를 하는 VAN사의 장애 시에 Switching Agent를 이용하여 또 다른 서비스 VAN사에서 결제 중계 서비스를 할 수 있도록 하는 신용카드 결제 시스템을 제안하였다.