• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.99-103
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• 2003

Recently, a fuel cell with low voltage and high current of electronic output characteristics is remarkable for new generation system. It needs both a dc-dc boost converter and do-ac inverter to be used in domestic power. Therefore, this paper presents do-dc boost converter with ZVS for fuel cell generation system This topology has several advantages, which are ZVS characteristics of all of main and auxiliary switches, reduction of reactor component size because of high frequency switching, and low rated voltage stress of the switches. In this paper, theoretical analysis, operation principle, and design procedures are presented. And simulation results from Pspice are presented to validate the theoretical analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.504-505
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• 2010

본 논문에서는 양방향 스위치를 가지는 기존의 5-레벨 인버터를 직렬 결합하여 보다 많은 출력 전압 레벨을 형성할 수 있는 멀티레벨 인버터 구조를 제안한다. 제안된 회로는 동일한 출력 전압 레벨 형성시 기존의 Cascaded H-bridge cell 방식보다 사용하는 스위칭 소자를 줄일 수 있어 시스템 크기, 비용, 전력 손실을 저감시킬 수 있는 장점을 가진다. 제안된 회로는 입력 전압원의 크기를 5의 배수로 구성함으로서 보다 많은 수의 레벨을 생성시킬 수 있는 특징을 가진다. 본 논문에서는 두 대의 5-레벨 인버터를 직렬 결합함으로써 25-레벨의 출력전압을 생성시킬 수 있는 인버터에 대한 특성을 분석하고 시뮬레이션과 실험을 통해 타당성을 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.467-469
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier, four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2163-2165
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• 1998

This paper presents an adaptive control scheme of a ballast for HID lamp for an automotive headlight. A flyback converter is used for the voltage step-up and for the control. A full bridge inverter is used as a ballast topology. The proposed control method is an adaptive output power control with a charge control. The developed ballast satisfies the requirement of a fast warm up characteristics and operating stability for an automotive application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2027-2029
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• 1998

We have developed a compact high frequency switch mode converter (HFSMC) power supply with DC 50 kV output voltage and 10 kW output power. Since the inverter circuit uses 25 kHz rescharging scheme, the current is flowing with t kHz. For the efficient output voltage transform performed a simple design process using the transformer principle and the commercial specification. For the DC 50 kV output, we employed 7 pa windings of secondary coils for the series stac connection of the output with full-bridge rectifi In this paper the design detail and the test re the high frequency transformer together with HFSMC power supply are presented.

• 전기학회논문지
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• 제56권11호
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• pp.1947-1954
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• 2007

This paper describes the development of a high-performance single-phase line-interactive Dynamic voltage Restorer, which is composed of an H-bridge inverter and super-capacitors. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with 3kVA prototype. The developed system can compensates the input voltage sag and interruption within 2ms, in which the maximum allowable duration of voltage interruption is 1.5 seconds. It can be effectively used to compensate the voltage interruption in the sensitive load, such as computer, communication equipment, automation equipment, and medical equipment. The developed system has a simple structure to be easily implemented with commercially available components and to be highly reliable in operation.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.316-325
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• 2013

Multilevel inverters produce a staircase output voltage from DC voltage sources. Requiring great number of semiconductor switches is main disadvantage of multilevel inverters. The multilevel inverters can be divided in two groups: symmetric and asymmetric converters. The asymmetric multilevel inverters provide a large number of output steps without increasing the number of DC voltage sources and components. In this paper, a novel topology for multilevel converters is proposed using cascaded sub-multilevel Cells. This sub-multilevel converters can produce five levels of voltage. Four algorithms for determining the DC voltage sources magnitudes have been presented. Finally, in order to verify the theoretical issues, simulation is presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.105-107
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• 2018

This paper presents a new hybrid multilevel converter topology, which consists of a combination of the series connected switched capacitor units with boost ability, and an H-bridge with T-type bidirectional switches. The proposed converter boosts the input voltage without any bulky inductors, and has the small number of components, which can make the size and cost of a power converter greatly reduced. The output filter size and harmonics are also reduced by the high quality multilevel output. In addition, there is no need for complicated methods to balance the capacitor voltage. Simulation and experimental results with a nine-level converter system are presented to validate the proposed topology and modulation method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.534-535
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• 2013

본 논문은 당사에서 개발한 5Mvar급 STATCOM(static synchronous compensator)의 제어 시스템에 대해 기술한다. 제작된 5Mvar급 STATCOM은 한 상당 12대의 HBI(H-Bridge Inverter)로 구성이 가능하도록 25-Level로 제작되었다. 제안된 제어시스템은 DSP(digital signal processor)를 이용하였으며, 하나의 Main Controller와 다수의 Cell Controller, FPGA 보드 등으로 구성되어 있다. Controller 간의 상호 정보를 교환하기 위해 eCAN 통신을 이용하였고, HBI의 스위칭을 위한 보드는 각각에 연결되어 있으며, Cell Controller보드와는 절연을 위해 광신호로 연결하였다. 본 논문에서는 개발한 제어시스템의 신뢰성을 검증하기 위한 실험을 진행하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.536-537
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• 2013

전기로와 같은 고압, 대용량의 산업응용분야에서 전원 안정화를 목적으로 하는 변동부하에 의해 발생되는 정상분 및 역상분의 무효전력을 보상하기 위한 고성능의 STATCOM의 개발이 요구되었다. 본 논문에서는 POSCO ICT에서 개발한 22.9kV 5MVA STATCOM(static synchronous compensator)에 대해 기술하였다. 개발된 STATCOM은 다단 멀티레벨 컨버터(Cascaded Multilevel Converter) 방식으로 Delta 구성하였으며, 각상당 12개의 H-Bridge Inverter가 직렬로 구성되어 25 레벨의 전압을 출력한다.