• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.121-127
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• 2012

An electric power compensation system for a DC transmission system with an integrated wind turbine generator is proposed. The proposed compensation system consists of a synchronous generator and a duplex reactor. This apparatus is connected to the sending-end circuit of the DC transmission system. A set of steady-state equations of the system is first derived. Then, the effect of the duplex reactor, which can eliminate the sending-end grid current distortion due to commutation of the converter, is explored. The relationships among power at the sending-end circuit are also revealed. It is shown that fluctuations in the sending-end grid power due to changes in wind velocities are compensated with the proposed system. Finally, the effects of the sending-end grid conditions on the steady-state characteristics of the system are studied.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.134-140
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• 2013

This paper proposes a new design of rotor shape of Interior Permanent Magnet Synchronous Motor (IPMSM) used for agricultural electric vehicle (AEV). The distribution of the residual magnetic flux density at the air gap is modified by rotor surface shape and V-type magnet angle. As a result, cogging torque and physical characteristic have been improved, and back electromotive force (back-EMF) of the suggested model has been improved to be closest to sine wave form compared to initial model. The validity of the proposed rotor shape optimization is confirmed by the manufactured IPM rotor core and measured the performance of the cogging torque.

• 디지털콘텐츠학회 논문지
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• 제4권2호
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• pp.139-146
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• 2003

본 논문은 ERA(Error Recovery Agent)의 설계와 구축을 설명한다. ERA는 멀티미디어 원격 교육 시스템에서 소프트웨어 오류를 감지, 공유, 복구하기에 적합한 시스템이다. 이 시스템은 ED, ES, ER로 구성되어 있다. ED는 훅킹 기법으로 오류를 감지한다. ES는 멀티미디어 원격 교육 시스템에서 오류를 공유하는 에이전트이다. ER은 오류를 복구하는 에이전트이다. 본 논문에서는 멀티미디어 공동 작업 환경에서 하나의 오류 응용을 미디어로 취급하고 복구하는 방법을 제안한다.

• 한국컴퓨터정보학회논문지
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• 제21권6호
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• pp.1-7
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• 2016

An uninterruptible power supply (UPS) allows small companies and domestic users to cope with power outages; but existing designs lack flexibility of control and require expensive battery maintenance, with a cost proportional to the outage compensation time. We combine a compact synchronous generator with a battery, with 10% of the capacity that would otherwise be required, to obtain a UPS with reduced maintenance costs for the same performance. Any UPS must respond immediately to a power loss, and our uninterruptible generator supply (UGS) is therefore built around real-time scheduling of its internal operations; this also makes it suitable for integration into the industrial gateway. The UGS is based on a real-time operating system, with an integrated wireless module providing connectivity to a web server, for monitoring and management, which can be performed remotely on a mobile device.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.781-784
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• 1993

Most linguistic models of processes or plants known are essentially static, that is, time is not a parameter in describing the behavior of the object's model. In this paper we show two models for synchronous finite state machines (FSM) based on fuzzy logic, namely the Crisp-State-Fuzzy-Output (CSFO FSM) and Fuzzy-State-Fuzzy Output (FSFO FSM). As a result of the introduction of the FSM models, the improved architectures for fuzzy logic controller have been defined. These architectures featuring pipelined intelligent fuzzy controller are discussed in terms of dimensionality of the model. VLSI integrated circuit implementation issues of the fuzzy logic controller are also considered. The presented approach can be utilized for fuzzy controller hardware accelerators intended to work in the real-time environment.

• 대한전기학회논문지:전력기술부문A
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• 제48권5호
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• pp.524-530
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• 1999

This paper describes performance analysis techniques for SSSC using computer simulations with EMPT and experiments with a hardware scaled-model. A switching-level simulation model with EMTP was developed for the SSSC connected in series with the transmission line. The increase of transmission capability and dynamic performance was analyzed with the simulation model. The simulation results were reverified by experimental works with a hardware scaled-model. The developed analysis techniques can be used for designing and evaluating actual system of SSSC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
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• pp.134-137
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• 2007

LMTT(Linear Motor-based Transfer Technology) 시스템은 항만 컨테이너 이송장치의 자동화 시템으로 기술적 포화상태에 이른 AGV (Automated Guided Vehicle)의 대체 수단으로 제안되었다. 본 논문에서는 PMLSM (Permanent Magnetic Linear Synchronous Motor)을 기본 구조로 한 LMTT에서 발생할 수 있는 레일과 차체간의 인척력 변화와 다양한 부하 중량에 대한 시스템 내부 변수의 변동에 적응할 수 있는 제어기 설계에 초점을 두었다. 그렇게 됨으로써 제어시 큰 방해요소로 작용하는 마찰력에 의한 백래쉬 및 데드존을 최소화하여 속응성 및 정밀도를 향상시키고자 하였다.

• 한국정보통신학회논문지
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• 제1권2호
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• pp.193-197
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• 1997

In this paper, we propose a new PN chip clock generator which employs two synchronous counters to achieve precise phase control of chip clock. In a CDMA code acquisition and tracking system, the PN chip clock is required to operate highly reliable without any glitch even under harsh environment condition such as temperature and voltage fluctu-aliens. The digital implementation of the proposed PN chip clock generator imparts it with much desired reliability. Since the proposed chip clock generator can be easily controlled into one of the states: free running, phase advance, and delay state, it can be applied to data processing as well as code synchronization. We have done FPGA implementation of the proposed logic and have verified its satisfactory operation up to 50 MHz.

• 전력전자학회논문지
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• 제7권1호
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• pp.91-100
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• 2002

본 논문에서는 매입형 영구자석 동기전동기의 전자기 토크의 맥동저감에 관하여 기술하였다. 일반적으로 토크 맥동은 전동기의 진동과 소음을 유발하는 중요한 원인이 된다. 제안된 방법에서는 비정현적인 역기전력을 가진 IPMSM에서 토크 맥동을 저감하기 위해 단위전류당 최대토크 제어를 할 수 있는 최적의 전류 형상을 고려하여 도출하였다. 그리고 이를 전동기에 인가했을 때 토크 맥동이 개선될 수 있음을 시뮬레이션과 실험을 통해서 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1319-1321
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• 2004

This paper presents a model and simulation for the korean type multi-propulsion system consisting of a gas turbine driven synchronous alternator coupled to a rectifier and dc-to-dc converter. The simulation modules include turbine system, alternator and rectifier, dc-to-dc converter, power management module. A modular, system level simulation of the propulsion system prototype is presented in order to confirm stability for loads with uncertain input impedances and uncertain control loop speeds.