• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.733-736
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• 2009

전력선 통신은 별도의 통신선로가 필요 없어 저렴한 설치비용과 설치가 용이하고 접근이 간편해 다양한 응용시장 하부 네트워크가 가능하나 제한된 전송 데이터와 통신 장애 요소인 높은 부하 간섭과 잡음 문제가 있으며 무선 센서 네트워크는 기반 시설이 불필요하고 센서 노드들 간의 자체적 네트워크 구축이 가능하여 짧은 시간에 구현이 가능하나 QoS의 향상을 위한 능동적 센싱과 불필요한 정보전송으로 인한 전력소모의 증가로 인해 센서 노드의 수명 단축 문제로 저전력 설계와 개선된 프로토콜의 필요성이 언급되고 연구되고 있다. 본 연구에서는 전력선 통신과 무선 센서 네트워크의 문제를 상호 보완하고 장점은 더하여 연동 통합제어 시스템을 구축함으로써 두 기술의 시너지 효과를 이용해 보다 제약이 없고 원활한 네트워크 환경구축을 위해 개선된 제어 네트워크를 구조적으로 접근해보려 한다. 하니웰 사의 하이브리드 센서 네트워크를 비교 분석하고 네트워크 티밍(Teaming)을 제안하며 제안된 전력선 통신과 무선 센서 네트워크의 연동 통합제어 시스템(Linkage Intergration Control System)의 성능 향상의 정도를 시물레이션을 통해 새롭게 제안한 방식의 네트워크 및 개선안이 기존의 네트워크보다 서비스 지연이 줄어들고 성능 향상이 있었음을 확인하려 한다.

• 한국인터넷방송통신학회논문지
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• 제20권4호
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• pp.195-200
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• 2020

화석연료 고갈과 환경오염에 관한 관심이 고조되면서 국내에서 운행되고 있는 철도차량이 디젤 차량에서 전기 차량으로 전환이 확대되면서 진행되고 있다. 전기 차량의 전환의 한 예로 적용되고 있는 태양광발전 시스템은 무한정하고 무공해 하며 대기오염, 소음, 발열, 진동 등과 같은 위해요소들을 발생시키지 않고 에너지 생산이 가능하며, 연료 수송, 발전설비에 대한 유지보수가 거의 필요하지 않은 장점이 있다. 그러나 전력생산량이 지역별 일사량에 의존하고, 약 25㎡/kWp 발전량으로 에너지밀도가 낮아 큰 설치 면적이 필요하며, 설치장소가 제한적인 문제점을 가지고 있다. 이러한 문제점을 고려하여 철도 분야에서도 연료전지를 적용한 연구들이 많이 증가하고 있다. 특히 연료전지 발전시스템 철도 급전계통 연계방안은 태양광 및 풍력과는 다르게 철도차량에 전력을 공급해주는 급전계통에 연계해야 한다. 따라서 철도차량과 밀접한 관계를 가지는 시스템 토폴로지 (topology)에 따라 연계방식은 크게 달라질 수 있으므로 본 논문에서는 시스템 토폴로지에 따른 연계분석과 관련된 시뮬레이션 모델링을 통한 타당성을 연구하고자 한다.

• 한국콘텐츠학회논문지
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• 제11권12호
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• pp.317-325
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• 2011

본 연구의 목적은 소아마비, 하지 근력약화 등의 장애인이 사용하는 잠금형 보조기무릎관절을 대체하기 위하여, 4절 연쇄 방식의 입각기조절형 보조기무릎관절을 개발하는 것이다. 본 연구에서 개발한 4절 연쇄 보조기무릎관절은 기존의 입각기조절형 보조기무릎관절과 달리, 기하학적으로 잠금상태가 제어되어 전기제어 부품 등이 필요하지 않으며 부피를 최소화하였다. 평가를 위하여, 소아마비로 진단받고 잠금형 보조기무릎관절을 사용해온 소아마비자가 대상자로 참여하였다. 대상자의 걸음걸이를 3차원으로 분석한 결과, 4절 연쇄 보조기무릎관절을 착용했을 때 입각기 동안 무릎관절의 신전이 유지되고 유각기 동안 무릎관절이 굴곡되며 자연스러운 걸음걸이를 보여주었다.

• 전기학회논문지
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• 제60권5호
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• pp.913-920
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• 2011

Distribution systems for operating the various systems should be operated organically. Distribution systems for organic operations extend the functionality of the system and system integration for the extension is doing. However, in systems integration for each unique non-standard definition of linkage and exchange systems are used. Non-standard definition of a unique linkage and exchange systems in the maintenance and expansion will result in many negative results. To solve these problems, the system and the exchange of information about the links between systems should define standards. IEC (International Electrotechnical Commission) power to solve these problems in the field of the Common Information Model (Common Information Model, CIM) standard (IEC61970, IEC61968) is defined as the transmission and distribution system integration and standardization for the exchange of information. In this paper, standardized system for building CIM-based distribution automation system should describe the process of building. In addition, the process of establishing a common information model needed (CIM) defined and associated services for a defined set of models is proposed in the standardization process.

• 전기학회논문지P
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• 제58권3호
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• pp.276-284
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• 2009

In this paper, we develop the image transfer remote maintenance monitoring system for hand held device which can compensate defects of human mistake. The human mistakes always happen when the worker communicate information each other to check and maintenance the equipment of the power plant under bad circumstance such as small place and long distance in power plant. A worker couldn't converse with other when in noisy place like Power plant. So, we make some hand device for handy size and able to converse in noisy place. The developed system can have improvement of productivity through increasing plant operation time. And developed system is composed of advanced H/W(hard ware) system and S/W(soft ware)system. The H/W system consist of media server unit, communication equipment with hand held device, portable camera, mike and head set. The advanced s/w system consist of data base system, client pc(personal computer) real time monitoring system which has server GUI(graphic user interface) program, wireless monitoring program and wire ethernet communication program. The client GUI program is composed of total solution program as pc camera program, and phonetic conversation program etc.. We analyzed the required items and investigated applicable part in the image transfer remote maintenance monitoring system with hand held device. Also we investigated linkage of communication protocol for developed prototype, developed software tool of two-way communication and realtime recording skill of voice with image. We confirmed the efficiency by the field test in preventive maintenance of plant power.

• 한국물환경학회지
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• 제27권2호
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• pp.147-158
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• 2011

This study analyzed the linkage characteristics between road runoff and the nearest streams in mountain regions using a discriminant analysis. The road-to-stream linkage is an important characteristic to evaluate whether the contaminant on road surface is transported directly into the nearby channel system. This study evaluated a total of 51 drainage outlets of mountain roads near the Soyanggang Dam. The linkage between road and stream, slope and width of road, and other information necessary for the discriminant analysis have been collected by in situ investigation and by analyzing the Digital Elevation Model. Finally, as independent variables in the discriminant analysis, the contributing road representing the road characteristics (similar to the runoff from the road drainage outlet) and the distance and slope of the connecting channel between road and nearest stream were selected. Among these three, the distance was found to have the highest discriminant power, the contributing road the lowest. Using the discriminant function derived, 40 out of 51 cases (78.4%) were correctly discriminated and the remaining 11 cases (21.6%) were wrongly discriminated. Reasons of wrongly discriminated cases were mainly due to change in drainage outlet direction, excessive runoff, change in road-to-stream path, etc. This result also indicates that the road-to-stream linkage can be introduced or prohibited by exactly the same way.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1614-1622
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• 2014

A novel equivalent flux sliding-mode observer (SMO) is proposed for dual three-phase interior permanent magnet synchronous motor (DT-IPMSM) drive system in this paper. The DT-IPMSM has two sets of Y-connected stator three-phase windings spatially shifted by 30 electrical degrees. In this method, the sensorless drive system employs a flux SMO with soft phase-locked loop method for rotor speed and position estimation, not only are low-pass filter and phase compensation module eliminated, but also estimation accuracy is improved. Meanwhile, to get the regulator parameters of current control, the inner current loop is realized using a decoupling and diagonal internal model control algorithm. Experiment results of 2MW-level DT-IPMSM drives system show that the proposed method has good dynamic and static performances.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.17-20
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• 1996

An adaptive current control scheme of a permanent magnet (PM) synchronous motor with the simultaneous estimation of the magnitude of the flux linkage and stator resistance is proposed. The adaptive parameter estimation is achieved by a model reference adaptive system (MRAS) technique. The adaptive laws are derived by the Popov's hyperstability theory and the positivity concept. The predictive control scheme is employed for the current controller with the estimated parameters. The robustness of the proposed current control scheme is compared with the conventional one through the computer simulations.

• 전력전자학회논문지
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• 제25권3호
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• pp.219-226
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• 2020

Given the change in the energy market, large energy storage systems (ESS) is rapidly entering the market. In this rapid spread, fire accidents are becoming an issue. This study attempts to approach the fire from the system point of view to analyze the problems caused by bonding from different perspectives. Moreover, to conduct this study, the fabrication of real objects is dangerous, which needs to be verified through simulation. In this study, we approach the cause of fire that occurs in large-capacity ESS from the system perspective. We focus on determining the effects of cell balancing performed on the BMS after charging. Thus, we analyze the cell balancing behavior and the linkage risks to the various stacks. The study also explores why no fire occurs during 70% operation.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권7호
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• pp.364-369
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• 2002

In this paper, 3-D magnetostatic finite element simulation of a rotux type Low-Tc superconducing (LTS) superconducting power supply, finite element method, cryogenic system, superconducting foil by generated magnetic flux from the rotating pole. The magnetic flux density on the superconducting foil caused by two exciters is therefore sufficiently greater than its critical magnetic flux density and it is an essential point in LTS power supply design. To establish the sufficient flux path of this machine, ferromagnetic materials is used in this power supply. When ferromagnetic materials is used at extremely low temperature, its characteristic of magnetization differs to that at room temperature. For this reason, special consideration is needed in the magnetic analysis of cryogenic systems. When the excitation current is 10A, the normal spot appears on superconducting foil. The results of this analysis are calculated and compared with the experimental results. The linkage flux due to the excitation current of 10, 20, 30, 40 and 50A are respectively $1.30{\times}10-4$, $2.67{\times}10-4$, $5.08{\times}10-4$ and $6.15{\times}10-4Wb$.