• Electronics and Telecommunications Trends
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• v.12 no.4 s.46
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• pp.52-69
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• 1997

정보 고속화(Information Super-Highway)를 위하여 요구되는 매우 많은 양의 데이터를 전송하기 위해 제안된 한 해결책이 ATM(비동기 전송 모드)으로, ATM은 데이터를 전송하는데 우수한 방법이 되지만 사무실이나 가정의 모든 디바이스를 연결하기에는 가격이 너무 비싸다. 이에 가격이 저렴할뿐만 아니라 ATM 네트워크와 홈 네트워크 사이에 중개 역할을 하기에 ATM 과 충분히 유사한 패킷 구조를 가지고 있어 ATM을 위한 상호 보완적인 디바이스 접속 기술이 될 수 있는 IEEE 1394 고성능 직렬 버스가 컴퓨터와 전문가 및 일반인용 전자 제품을 위한 디지털 데이터의 전송에 대변혁을 일으키고 있다. 본 고에서는 확장성이 있는 구조 및 유연한 peer-to-peer 토폴로지에 의해 컴퓨터와 하드 드라이버로부터 디지털 오디오 및 비디오 하드웨어에 이르기까지 각 디바이스들을 연결하는 이상적인 디지털 접속 기술로 부상하고 있는 IEEE 1394 고속 직렬 버스의 특징과 기술 동향을 고찰함으로써 향후 이 분야의 기술 개발에 활용하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.600-606
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• 1992

The series connection of power switching semiconductor elements is essential when a high voltage converter is made, so researches are being conducted to further develop this technology. In the series connection of power switching semiconductor elements, the main problem is that simultaneous conduction at turn-on and simultaneous blocking at turn-off together with voltage balancing are unattainable because of the difference of their switching characteristics. In this paper a novel series connection algorithm is proposed, which can implement not only the synchronization of the points of turn-on and turn-off time but the dynamic voltage balancing in spite of the difference of each switching characteristics. The proposed method is that the compensated control signal is attained from the voltage feedback signal and applied to the series-connected power transistors independently. Computer simulation and experimental results verify its validity.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1075-1077
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• 2003

본 논문에서는 직렬주입변압기가 없는 다중브리지 형태의 새로운 UPFC를 제안하고 그 특성을 분석한 내용에 대해 기술하고 있다. 송전계통에 적용 가능한 UPFC의 새로운 토폴로지를 제안하고 상세모델을 통하여 계통의 전력조류제어 및 파도상태시의 동특성을 시뮬레이션 한다. 1기무한모선 전력계통인 138kV 송전선로에 UPFC가 연결되어 있는 것으로 가정하여 제안하는 시스템의 동특성을 EMTDC 시뮬레이션으로 분석하였다. 제안하는 시스템은 직렬주입변압기가 없이 직접 선로에 연결하는 것이 가능하다. H-브리지 인버터의 수를 증가시킴으로써 동작전압을 유연하게 높일 수 있다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.443-444
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• 2015

본 논문에서 제안된 충 방전기는 입 출력 절연을 통하여 안전성 향상하였고 3개의 변압기를 1차 측은 직렬로 연결하여 변압기에 권선비를 줄임으로써 충 방전기의 소형 및 경량화를 성취하였고 2차 측을 병렬 연결하여 스위칭 소자에 걸리는 전류 스트레스를 감소 시켰으며 컨버터 절연부에 직렬 공진형 Soft Switching 방식을 적용하여 높은 스위칭 주파수에서도 충 방전기에 고효율화가 가능함을 검증하였다. 본 논문에서 제안하는 내용은 PSIM를 이용한 시뮬레이션 결과로 그 타당성을 입증하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1482-1483
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• 2007

SI-Thyristor는 스위칭 특성상, turn on시에는 전압구동 특성을 지니며, turn off시에는 전류구동 특성과 전압구동 특성을 지니고 있기 때문에, 그 두가지 특성을 명확히 하여 스위칭 특성을 구분 짓는 것이 어렵다. 본 논문은 SI-Thristor-정전유도용량 사이리스터-의 펄스파워 어플리케이션으로 고안된 게이트 드라이버를 이용하여 직렬연결 특성을 측정했으며, 펄스파워 어플리케이션으로서의 SI-Thrysitor의 스위칭 특성과 그에 적합한 게이트 드라이버의 개선점과 특성에 대하여 기술되어 있다.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.443-452
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• 2002

A new phase shift full bridge (PSFB) converter with serially connected two transformers for telecommunication equipments of several hundred watts is proposed. The main features of the proposed converter are a wide input voltage range, an easiness to meet the requirement for zero voltage switching (ZVS) condition at a light load, and a small output voltage ripple. Furthermore, the serially connected two transformers can replace both a main transformer and an output inductor since the two transformers act as not only a main transformer but an output inductor by turns. Therefore, there is no need to use an output inductor, then the proposed converter features high power density. A mode analysis, design equations through a large signal modeling, and experimental results are presented to verify the validity of the proposed converter.

• The Journal of the Acoustical Society of Korea
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• v.26 no.6
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• pp.269-275
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• 2007

Pervasive Multi-channel audio systems are being realized due to advances in digital technology. This paper proposes an efficient system that serially connects individual speakers with bidirectional digital communication capability by means of SoC design. In particular, each speaker can identify the bit stream assigned to the speaker and convert it into analog audio. Furthermore, the speaker can self-diagnose the speaker functionality by utilizing the designed capability to measure frequencies of various square wave test signals. The proposed system running on 200MHz clock yielded restoration of analog output signal with latency of only $500{\mu}s$ compared to directly driving the speakers in a traditional way.

• The Journal of the Acoustical Society of Korea
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• v.24 no.7
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• pp.387-394
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• 2005

In this paper, we propose a new transmission technique of audio signals for the serial connection of the speakers of multiple-channel audio systems. Analog audio signals from a multi-channel audio system are converted into digital signals with signal processing steps and transferred to each speaker through a serial line. The signal processing steps contain data compression and packet generation in association with audio signal characteristics. Each speaker gets its corresponding digital audio signals from the transmitted packets and converts the signals into analog audio signals to make sounds with the speaker All the proposed functions in this paper are modeled in VHDL. implemented with FPGA chips, and tested for actual multi-channel audio systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.8
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• pp.329-333
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• 2006

We investigated the quench characteristics of a flux-lock type superconducting fault current limiter (SFCL) depending on the number of the serial connection between the superconducting elements at the subtractive polarity winding of a transformer. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting elements in series. The operation of the flux-lock type SFCL can be divided into the subtractive and the additive polarity windings depending on the winding directions between the primary and secondary coils. In this paper, the analyses of voltage, current, and resistance of superconducting elements in serial connection were performed to increase the power capacity of flux-lock type SFCL. The power burden was reduced through the simultaneous quenching between the superconducting elements. This enabled the flux-lock type SFCL to be easy to increase the capacity of power system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.26-30
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• 2008

The simulation and experiment for the fault current limiting characteristics of the superconducting fault current limiter (SFCL) using the magnetic coupling of series connected two coils were performed. The magnetic fluxes generated from two coils were canceled out during a normal time. However, the resistance generation of high-Tc superconducting (HTSC) element after a fault occurrence allows the magnetic fluxes of two coils and contributes to the fault current limiting operation. Through the computer simulation and the current limiting experiment for this SFCL, the operational current and the limiting impedance of the SFCL could be confirmed to be improved by adjusting the inductance ratio of two coils.