• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1967-1977
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• 2014

In this paper, for the development of a safe and reliable DC home appliance suitable for DC home power supply system, we classified a number of inherent problems with help of the comparative analysis of existing AC and new DC home appliance. Several new technical problems of DC home appliances are mainly linked to the DC transient state. Among them, this paper concentrates on start-up inrush current problem, uni-polarity problem, and heavy DC load control problem. And to address these problems, we herein present an implementation of robust safety circuits for DC home appliances. Specifically, we investigate several multi-circuit countermeasures and select the best among them through comparative evaluation, based on theoretical, simulational, and experimental results.

• 전력전자학회논문지
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• 제18권5호
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• pp.413-421
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• 2013

This paper proposes residential hybrid distribution system that can supply AC power and DC power to AC load and DC load at the same time. This hybrid distribution system consists of three parts: bidirectional inverter, step-up converter and step-down converter. Also that is used to supply voltage to home application is classified of AC load and DC load as load characteristics. The performance of proposed hybrid distribution system is validated through the hardware implementation and the experimental results.

• 전력전자학회논문지
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• 제12권2호
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• pp.174-182
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• 2007

신재생에너지 중에서 태양광 에너지가 중요 에너지원으로서 각광받고 있고 적용이 증대되고 있다. 특히, 미래에는 하이브리드 태양광 발전 시스템이 독립 분산 전원 시스템으로 널리 사용될 것으로 예상되고 있다. 본 논문에서는 DC전력을 기계적인 접촉에 의해 전달하는 것보다는 마그네틱 커플링에 의해 비접촉으로 에너지를 전달 할 수 있는 무접점전원장치를 사용한 직류수용가 서비스 태양광발전시스템을 제안하였다. 제안 적용된 무접점 전원장치는 무접점 변압기와 Half-bridge LLC 공진컨버터, 영 전압 스위칭 Boost컨버터로 구성되어 있다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.104-107
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contact-less power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.483-491
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• 2012

It is expected that, in the future, DC power service will be widely used for photovoltaic home power generation systems, since DC consuming devices are ever increasing. Instead of using multiple converters to convert DC to AC and then AC to DC, the power service could solely be based on DC. This would eliminate the need for converters, reducing the cost, complexity, and possibly increasing the efficiency. However, configuration of direct DC power service with mechanical contacts can cause spark voltage or an electric shock when the switch is turned on and off. To solve these problems, in this paper, a contactless power supply for a DC power service that can transfer electric power produced by photovoltaics to the home electric system using magnetic coupling instead of mechanical contacts has been proposed. The proposed system consists of a ZVS boost converter, a half-bridge LLC resonant converter, and a contactless transformer. This proposed contactless system eliminates the use of DC switches. To reduce the stress and loss of the boost converter switching devices, a lossless snubber with coupled inductor is applied. In this paper, a switching frequency control technique using the contactless voltage sensing circuit is also proposed and implemented for the output voltage control instead of using additional power regulators. Finally, a prototype consisted of 150W boost converter has been designed and built to demonstrate the feasibility of the proposed contactless photovoltaic DC power service. Experimental results show that 74~83% overall system efficiency is obtained for the 10W~80W load.

• 한국산업융합학회 논문집
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• 제20권4호
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• pp.275-284
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• 2017

As the high-level of the industrial and information age, the electricity become the indispensable element in the daily life including OA, FA, and computer, electric home appliances, and etc. In particular, The continuous use of the high capacity power supply system by applying a Switching Mode Power Supply(SMPS) according to the increase of the secondary side output terminal of the power load of the refrigerator of the home appliance or automation of the plant is pressed. The purpose using the way with this kind of high-capacity altogether is to supply the output voltage and output current regardless of the input voltage or to the external environmental conditions of the secondary-side load fluctuation. In this paper, a combination of a Buck Converter with Boost Converter by making a constant current source to control the inductor current and maintain stable power supply side operating characteristics, when load variations. While maintaining the same characteristics as conventional Buck Converter, and offer a DC-DC Converter system with the new switch pattern having a wide output range capable of operating in Buck-Boost Converter. In addition, after theoretical analysis, we carry out simulations and experiments to verify the validity and performance comparing with a conventional DC-to-DC converter.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.51-57
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• 2012

This paper provides a safety guideline for DC supplied home appliances through the comparative analysis of existing safety guideline for AC supplied home appliances. For this purpose, a predictive DC home appliance model is suggested and in special international safety standards of AC appliances are also analyzed. Moreover, a DC distribution system is built to verify the validity of the proposed safety guideline. The detailed analyzing process is explained with help of informative experimental results.

• 한국산업융합학회 논문집
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• 제25권4_1호
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• pp.493-504
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• 2022

Recently, as interest in eco-friendliness grows, the supply of hybrid electric vehicles and pure electric vehicles (EVs) for improving fuel efficiency of automobiles is rapidly expanding. The average daily energy consumption of electric vehicles is less than 20 [%] of the total ESS capacity of the vehicle, and research on additional functions using the ESS of the vehicle is urgently needed to expand the supply of electric vehicles. V2H(Vehicle to Home), like V2G(Vehicle to Grid), includes the concept of cooperating with system stabilization using ESS of electric vehicles. In addition, it includes various operations that can realize home welfare, such as uninterrupted power supply in case of power outage at home, and power supply for home DC devices. Therefore, in order to expand the supply of eco-friendly electric vehicles, it is urgently required to develop a V2H system with various functions that can realize home welfare. In this paper, we propose a V2H system with a CLLC resonant converter and a non-isolated step-up converter that can solve different impedance and resonant frequencies depending on the power transfer direction. The proposed V2H system is 6 [kVA] applicable to 150-450 [V], the voltage range that can use the ESS voltage for electric vehicles, and is designed with a capacity that can handle instantaneous electricity use at home. In addition, in order to verify the feasibility, an experiment by Psim simulation and prototype production was performed.

• 한국인터넷방송통신학회논문지
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• 제14권5호
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• pp.111-115
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• 2014

전력선 통신은 전기를 사용할 수 있는 어느 곳에서든지 데이터 전송 네트워크를 구축하기 위해 사용할 수 있다. 이러한 종류의 통신 시스템은 스마트 그리드와 홈 네트워크를 포함한 다양한 적용 분야에서 네트워크 구축을 위한 기반으로 제공된다. 반면에 전력선 통신은 다양한 종류의 간섭과 잡음에 취약하다. 또한 네트워크에 연결된 전기적 부하의 양과 종류에 따라 전력선 통신 채널의 특성이 지속적으로 변화한다. 특히 일상생활에서 스마트 기기의 폭발적인 증가에 의한 직류전원 공급장치의 사용이 증가함에 따라 전력선 통신 채널의 간섭 영향이 증가한다. 본 논문에서는 실험을 통하여 직류전원 공급장치의 동작에 따른 전력선 통신 채널의 영향과 데이터 전송 성능을 분석한다.

• 한국전자파학회논문지
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• 제16권2호
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• pp.189-193
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• 2005

본 논문은 MB-OFDM UWB 시스템에 적용할 수 있는 직접 변환 방식용 하향 주파수 변환기 구조를 제안한다. 제안하는 주파수 변환기 구조는 $3\~5\;GHz$ 광대역 입력 매칭을 하기 위해 일반적으로 CMOS로 구성된 트랜스컨덕턴스 회로를 사용하지 않고, 저항을 사용하였다. 하향 주파수 변환기는 $0.18\;{\mu}m$ CMOS 공정으로 구현하였으며, 측정 결과 3개의 UWB 채널에 대하여 최소 +3 dB의 주파수 변환 이득과 각각 3 dB 이하의 게인 평탄도를 보이며, 1.8 V dc Power supply에서 0.89 mA를 소비한다.