• The Magazine of the IEIE
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• v.20 no.9
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• pp.82-89
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• 1993

새로운 개념의 인버터로서 종래의 인버터의 직류부에 공진회로를 설치하여 직류와 교류를 공진 DC 링크로 접속하는 방식이다. 공진동작으로 링크부의 전압이 명이되는 것을 이용하여 인버터의 PSD를 ZVSAT킨다. (PSD = Power Switching Device)전압공진형은 ZVS가 가능하나 어느 정도의 전류를 OFF할 필요가 있기 때문에 비교적 TURN OFF의 속도가 빠른 MOSFET, SIT, IGBT등의 PSD를 이용하여 수십 kHz의 스위칭 을 한다. 여기에 대하여 전류공진형은 ZCS(Zero Current State)가 가능하게 되고 OFF하는 전류도 작게되기 때문에 TURN OFF가 늦은 BJT와 GTO. IGBT 싸이리스터 등의 TURN OFF 시간이 꾀 짧은 것들을 이용하여 수십 kHz의 스위칭이 가능하게 된다. 이들 PSD는 대용량화에 적합하여 대용량 전력변환기에의 적용이 시도되고 있다. 여기에서는 이들 인버터에 관하여 기본적인 동작원리와 제어방식을 중심으로 설명한다. 또한 공진형 방식의 결점인 전압과 전류의 피크치를 저감하는 전압 Clamp식에 관하여도 기술한다.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1281-1283
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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 saying result compared to the other systems due to elimination of 60Hz transformer.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.60-68
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• 2010

Recently, Power Conditioning System (PCS) tends to require more compact, higher efficiency and power density with better performance. A novel topology consisted of LLC resonant inverter and Low Frequency (LF) cyclo-converter for connecting to utility line is able to meet these requirements. The technical operating analysis is described and 1kW prototype is tested and verified the performances through connecting the 110Vac 60Hz utility line. Efficient results are described.

• Proceedings of the KIEE Conference
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• 2001.04a
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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.

• Electronics and Telecommunications Trends
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• v.27 no.6
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• pp.104-113
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• 2012

2012년 6월 30일자로 방송통신위원회에서는 10~60GHz 대역의 고정업무용 주파수 지정에 관한 입안 예고를 공고한 바 있다. 본고에서는 이 입안 예고의 배경이 되는 고정업무에 관한 국제 표준화 기구인 ITU-R(International Telecommunication Union-Radio Sector) 연구반의 표준화 동향에 대해 소개하고, 고주파 대역, 고정업무 시스템의 국내외 기술개발 동향을 소개한다. 또한, 국내외 고주파 대역 이용 현황을 국내 현황과 비교하고, 이를 통해 입안 예고된 고정업무용 주파수 지정의 개정 방안에 대해 간략히 소개하여, 향후 국내 전파통신망의 미래상을 전망할 수 있도록 한다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1050-1052
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• 2000

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.

• Journal of the Korean Solar Energy Society
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• v.22 no.3
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• pp.11-20
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• 2002

This paper proposed a MPPT(Maximum Power Point Tracking) control algorithm for PV(Photovoltaic) array based on a modified constant voltage control MPPT algorithm at low insolation. This method which combined a reference voltage control and a constant voltage control algorithm. In contrast to the typical conventional MPPT algorithm, the proposed method have been obtained high efficiency and good performance in all insolation intensity. The proposed algorithm is verified through simulation and experiment.

• 전기의세계
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• v.45 no.7
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• pp.39-44
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• 1996

전력변환 시스템의 고성능화를 위해서는 스윗칭 주파수를 고주파수로 하는 것이 필요하다. 그러나 PWM방식에서는 반도체 소자를 강제적으로 스윗칭시키기 때문에 고주파 스윗칭을 행하면 EMI, EMC 문제를 무시할 수 없게 되고 스윗칭 손실은 스윗칭 주파수와 함께 증가한다. 이 문제를 해결하기 위해 1986년에 미국 위스콘신대학에서 당초 인공위성 등에 탑재하는 직류전원으로서 직류/직류 컨버터의 공진 스위치였던 회로구성을 3상 직류링크 전압형 인버터에 전개하여 소프트 스윗칭이 가능하게 되는 교류전원용의 전압형 인버터를 발표하였다. 또한 그 당시에 또 다른 공진형 회로구성인 교류링크 인버터도 발표되었다[3-5]. 이러한 배경으로 이하에서는 PWM 전력변환기의 소개를 시작으로 고주파수화의 필요성 및 그로 인해 파생되는 문제점을 고찰하고, 공진형 전력변환 시스템의 필요성에 대하여 논한 뒤 각종의 공진형 변환기에 대하여 간략하게 설명하고자 한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.3
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• pp.244-252
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• 2002

In this paper, do link ripple currents for three-phase ac/dc/ac PWM converters feeding adjustable speed ac machine drives are analysed in a frequency domain. The expression of the harmonic currents is developed by using switching functions of the converter and exponential courier series expansion. The effect of the displacement angle between the switching Periods of line-side converters and motor-side inverters on the dc link ripple currents is Investigated. Also, the influence of asynchronization of PWM is observed. The result of analysis is compared with frequency spectrum which results from PSIM simulation. The proposed analysis technique is useful to understand the principles of P% and to derive an equivalent model of the dc link capacitors in a high frequency range.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.100-106
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• 2005

Generally, high frequency switching DC-DC converter that DC power supply for discharge lamp drive to generate ultraviolet rays(UV) is acted by hard switching mode is used. Therefore in this paper, wish to mix first existent first-side status phase shift PWM DC-DC converter and posing secondary-side status phase shift PWM DC-DC converter by high frequency link DC-DC converter that use soft switching circuit technology and develop DC power supply for discharge lamp drive. DC power supply driving Discharge lamp proposed describe validity through simulation and an experiment.