• 디지털산업정보학회논문지
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• 제14권1호
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• pp.15-25
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• 2018

ISO/IEC 15118 is a standard for communications and services for electric vehicle charging infrastructure. Although this standard deals only with data communication between an electric vehicle and a charge station, communication with the outside is essential for establishing an authentication system for vehicle certification and V2G service for electric power transmission. In this study, it was designed to verify the information of electric car charging infrastructure in electric power system through communication link between ISO/IEC 15118 electric vehicle model and IEC 61850 standard MMS protocol. This is demonstrated in the field so that the electric vehicle communication data is linked with the micro grid management system. This could be used as an element technology in other distributed power sources as well as electric cars in the future.

• 전력전자학회논문지
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• 제21권2호
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• pp.144-149
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• 2016

This paper presents a power control method of high-speed single-phase BLDC motor. Most electric appliances require a power factor corrector (PFC) to mitigate grid current harmonics. However, the reactive components and power semiconductors in the PFC increase system cost and dimension. In this paper, a new motor drive system for a high-speed single-phase BLDC motor is proposed, which can decrease grid current harmonics without PFC by directly manipulating motor power and eliminating bulky electrolytic dc-link capacitor. Given that the proposed motor power control method does not require motor current controller, no current sensor is necessary. Moreover, the proposed algorithms can be easily implemented using a low-cost micro-controller. The effectiveness of the proposed power control method is verified by experiments.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.469-470
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• 2007

• Journal of Welding and Joining
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• 제21권3호
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• pp.92-98
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• 2003

This paper describes the numerical prediction of the thermal fatigue life of a $\mu$BGA(Micro Ball Grid Array) solder joint. Finite element analysis(FEA) was employed to simulate thermal cycling loading for solder joint reliability. Strain values, along with the result of mechanical fatigue tests for solder alloys were then used to predict the solder joint fatigue life using the Coffin-Manson equation. The results show that Sn-3.5mass%Ag solder had the longest thermal fatigue life in low cycle fatigue. Also a practical correlation for the prediction of the thermal fatigue life was suggested by using the dimensionless variable ${\gamma}$, which was possible to use several lead free solder alloys for prediction of thermal fatigue life. Furthermore, when the contact angle of the ball and chip has 50 degrees, solder joint has longest fatigue life.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.484-485
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• 2008

A micro-grid (MG) is a new concept to aggregate distributed generations (DGs) and loads in a small area. The difference between MG and DG is that MG can supply power to loads even in islanding conditions. The magnitude of the fault current depending on interconnection between the MG and utility and the number of DGs in the MG. Therefore, the setting value of the OCR must be changed depending on operating conditions of the MG. This paper proposes the over-current relay considering operating conditions of the MG. In the proposed algorithm, the supervisory control and data acquisition decides the operating conditions of the MG and sends the proper setting values to each OCR. The performance of the algorithm was investigated in the case of the various operating conditions.

• 마이크로전자및패키징학회지
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• 제8권3호
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• pp.1-9
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• 2001

본 논문에서는 마이크로 납볼 격자 배열 ($\mu$BGA)패키지의 검사 알고리듬을 제안하였다. 이 알고리듬의 개발은 납볼 배열의 미세 크기 때문에 사람의 사각으로는 결함을 식별하기 어려운 점에 기인하였다. 특히, 여기에서 보인 자동 시각 $\mu$BGA 검사 알고리듬은 소위 말하는 이차원 오차뿐만 아니라 볼의 높이 오차까지 검사할 수 있다. 검사 알고리듬은 특수하게 제작된 청색 조명 하에서 이차원 $\mu$BGA 영상을 사용하고 회전 불변 알고리듬으로 영상을 처리하였다. 그리고 2개의 카메라를 사용하여 높이 오차를 검출할 수 있었다 모의실험결과, 제안한 알고리듬이 기존 방법에 비하여 괄목할 만큼 납볼 결함을 검출할 수 있음을 보였다.

• 한국정보통신학회논문지
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• 제25권10호
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• pp.1381-1390
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• 2021

지능형 전력망은 제어시스템, 전력망, 수용가로 구성되는 세 가지의 광범위한 보안 영역을 다루는 대표적인 4차 산업혁명 시대의 융합 신기술이다. 융합 신기술인 만큼 향후 국가의 기술발전과 성장동력, 경제성 등에 많은 긍정적인 영향을 미칠 수 있지만, 만약의 보안사고 발생 시에는 막대한 피해가 예상되기 때문에 에너지 관련 기관은 최신의 각종 보안 사고들을 예측하고 대응할 수 있는 다양한 보안대책들이 마련되어야 한다. 본 논문에서는 국내외 스마트그리드 현황과 보안표준 동향, 그리고 취약점 및 위협을 살펴보고, 앞으로의 스마트그리드 보안기술 전망에 대해 고찰해 보고자 한다.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.121-126
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• 2016

Hydraulic performance of a micro-bubble pump has been analyzed by numerical simulation and experimental measurements. Flow recirculation apparatus between the pump inlet and outlet reserviors has been adopted to measure pump performance according to flow conditions sequentially. To analyze three-dimensional flow field in the micro-bubble pump, general analysis code, CFX, is employed. SST turbulence model is employed to estimate the eddy viscosity and compared the pump performance to k-${\varepsilon}$ model. Unstructured grids are used to represent a composite grid system including blade, casing and inlet casing. It is found that the numerical model used in the present study is effective to evaluate the pump performance. From the numerical simulation, low velocity region due to pressure loss is decreased where pump efficiency has maximum value. Detailed flow field inside the micro-bubble pump is also analyzed and compared.

• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.901-909
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• 2016

Unprecedented attention is being given to Smart Grid, Micro Grid and Internet of Things (IoT) in the Republic of Korea recently but such systems' effect is not well experienced by the market since they require additional and costly reforms for the existing household electrical system where adaptive communication platforms are needed. As such platforms, both wireless and wire communication technologies are being considered at the moment. Usually, they include WiFi, Zigbee technologies and the latter, LAN technology. However, communication speed decline due to signal attenuation and interference during wireless communications are considered to be the major problem and the extra works involving time and costs for the LAN system construction can be another demerit. Therefore, in this paper, we have introduced a Power Line Communication-based Smart Outlet System Expandable at Home to complement these disadvantages. Proposed IoT system involves Power Line Communication (PLC) technology which is essential to constructing a Smart Grid.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.105-110
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for grid-connected operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of Power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in grid-connected operation mode of a DG system. The control strategies for grid connected operation mode of DG system is also presented.