• Journal of Power Electronics
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• 제15권5호
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• pp.1348-1357
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• 2015

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation andexperimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

• 전력전자학회논문지
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• 제6권4호
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• pp.307-316
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• 2001

본 논문에서는 직류 특성과 절전 모드에서 비절전 모드 변환과 같은 부하 변동 시의 동특성을 동시에 개선할 수 있는 가중치 전압 제어를 적용한 PC 전원용 다중출력 포워드 컨버터를 설계하였다. 기생성분을 포함한 전력회로를 모델링하고 소신호 해석하였으며, 가중치 결정 방법과 전압 보상회로 설계 방법을 제시하였다. SABER 시뮬레이션과 실험을 통해 제안한 방법이 PC 전원의 직류 특성과 동특성을 향상시킴을 입증하였다.

• 한국정보과학회논문지:정보통신
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• 제37권5호
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• pp.403-408
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• 2010

센서 노드는 사막, 도시, 데이터 센터등과 같이 온도의 변화가 심한 환경에 설치될 수 있다. 특히 온도가 증가하게 되면 설정한 파워에 비해 출력되는 파워가 감쇄되기 때문에 RSSI와 같은 링크 품질의 저하를 초래하며, 패킷 손실이 발생될 수 있다. 무선 환경에서 온도의 변화를 보상하기 위한 노드간에 링크 품질의 변화를 파악하고 일련의 피드백 과정을 통하여 전송파워 제어하는 기존의 방법이 있으나, 추가적인 제어 패킷들이 많이 발생하는 문제점이 있다. 본 논문에서는 이러한 온도 변화에 따른 링크품질의 유지를 위하여 T2PC(Temperature-aware Transmission Power Control)를 제안하였다. T2PC는 각 노드에서 자체적으로 얻을 수 있는 온도정보를 이용하여 전송파워를 제어함으로서 감쇄된 랭크 품질을 보상하도록 하였다. 또한 기존의 피드백을 이용한 전송파워 제어 기법보다 적은 컨트롤 패킷으로 패킷 수신율을 향상시켰다.

• 전기학회논문지P
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• 제63권2호
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• pp.89-94
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• 2014

Tidal generation has become one of environmentally friendly new and renewable future sources of energy. The Sihwa Tidal Power Plant in South Korea, which was imported from abroad by turnkey type in 2011, connected to the power system in 2012, and is currently under commercial operation. However, leading companies are reluctant to disclose their technologies associated with the control systems and are not cooperative in technology transfers, making it a high priority to develop core technologies in South Korea. In order to develop a start stop control system for tidal generation, this paper presents the optimal algorithm for decision making and prototype of hardware design. First, control systems in tidal power, such as plant operation control, data interfaces between systems, monitoring and control points of the control system, are analyzed. The software development and PC based emulator processes for optimization algorithm processing are described. Finally, verification of the algorithm implementation, hardware platform for start stop control device, and implementation of prototype control system were discussed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.501-504
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• 2000

In this paper the PC power supply is studied from the point of system stability. The power stage model of a multiple output forward converter with weighted voltage mode control is derived including all the major parasitic components and the small signal model is also derived. Determination of the weighting factors and a design procedure for the loop compensation are presented. Finally the model is verified through the simulation of three output forward converter with SABER.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.580-582
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• 2008

The object of this paper is develope the PC based controlled high voltage power supply and studies 1.2kW(120kV, 10mA) pulse power X-ray generator possible to adapt fluoroscopy of Dental CT X-ray generator and industrial X-ray pulse power equipment. The developed pulse power X-ray generator consisted of mono-block tank include X-ray tube and high voltage X-ray power supply circuit and high voltage control unit with RS232C/422 communication port. The PC control program of pulse power X-ray generator uses LabVIEW, and the size of high voltage transformer and high voltage generator is minimized by high voltage high frequency inverter has 100kHz switching frequency. Also this paper shows result of X-ray tube voltage and tube current correspond to variable load.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2697-2710
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• 2018

Owing to the development of Internet of Things (IoT), the fifth-generation (5G) wireless communication is going to foresee a substantial increase of mobile traffic demand. Energy efficiency and spectral efficiency are the challenges in a 5G network. Non-orthogonal multiple access (NOMA) is a promising technique to increase the system efficiency by adaptive power control (PC) in a 5G network. This paper proposes an efficient PC scheme based on evolutionary game theory (EGT) model for uplink power-domain NOMA system. The proposed PC scheme allows users to adaptively adjusts their transmit power level in order to improve their payoffs or throughput which results in an increase of the system efficiency. In order to separate the user signals, a successive interference cancellation (SIC) receiver installed at the base station (BS) site. The simulation results demonstrate that the proposed EGT-based PC scheme outperforms the traditional game theory-based PC schemes and orthogonal multiple access (OMA) in terms of energy efficiency and spectral efficiency.

• 디지털산업정보학회논문지
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• 제9권3호
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• pp.49-57
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• 2013

Power-saving PC software enables the inexpensive power control, but the installation of the power-saving software in all computers in the organization is not an easy task. Computer users in the organization are usually not cooperative as they do not think the power-saving cost is directly related to themselves. The PC power-saving system provides advantage to driving active participation in which users installs the power saving software by restricting IP address through the power management server. However, the problem with this approach is the security vulnerability to IP spoofing attacks, therefore we need to solve the problem that disrupt the entire network system rather than saving electric power. This paper proposes the security authentication system that can implement the efficiency saving power by providing high security for the members' computer system of the public institutions based on the PC power-saving system. Also, by analyzing it in comparison with other method, it is possible to check that the prospects of safety and efficiency are strengthened.

• Journal of Advanced Marine Engineering and Technology
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• 제35권2호
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• pp.288-294
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• 2011

본 논문에서는 FPGA기반의 SoC보드(Xilinx Virtex-4 ML401 EVM)를 이용한 전력인버터제어시스템을 설계하였다. 선박에 전력시스템을 적용하기 위해서 선박의 최신 통신 프로토콜인 NMEA 2000 표준 프로토콜을 적용하였으며 전력 시스템의 성능을 평가하기 위한 PC기반의 모니터링 프로그램을 제작하였다. 전력 제어시스템은 FPGA기반의 임베디드 SoC보드상에서 이중프로세서(Dualprocessor)형태로 설계하였으며 이중프로세서를 적용함으로써 실시간 제어 감시가 가능하다. 이중프로세서 중 하나는 전력 제어를 위한 PWM신호생성 및 전력 회로내의 주요 전력 파라미터를 센싱 하는 제어용 프로세서로 동작하며(Control processor) 다른 프로세서는 제어프로세서의 각종 전력 센서 파라미터와 제어 파라미터들을 이중포트 램(Dual Port RAM)을 이용하여 정보를 공유하고 외부 NMEA 2000프로토콜 기반의 모니터링 장치와 네트워크 기반의 통신을 수행하는 통신용 프로세서(Communication processor)로 구성된다. 본 논문에서 제작한 전력 제어시스템은 선박내의 분산발전,송배전 및 전압 레귤레이션 시스템에 적용 될 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.362-367
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• 2005

Control network adopted in the national power-plant or manufactory are mostly vendor-dependent products, which have their own special specification, components and individual communication methods. These systems not only raise installation cost, but also bring many difficulties to maintenance and extension. To overcome these problems, this paper introduces a development and application case of a new "PC/Ethernet-based fieldbus" architecture and protocol to be used in mid-level fieldbus. The designed system has a basic idea of "3 Layers fieldbus over Standard-LAN" and implemented on PCs. PC gives user friendly environment. By using an open standard Ethernet in layer 1,2, the system has low cost, wide communication bandwidth and high compatibility. Layer 3 protocol designed for large realtime data communication makes user bypass TCP/IP layer and gives user direct access to the Ethernet. This new protocol eliminates potential collision of Ethernet, and transmits large periodic/non-periodic control data by using long-frame/wide-bandwidth of Ethernet effectively, and offers simple API-Services to the upper layer. Since the system have installed in H-power plant simulator and U-nuclear power plant simulator in Korea, it have been proved to be efficient and stable without any trouble in realtime communication service for full-scope plant simulator that has a lot of control elements.