• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.892-895
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• 2011

SoC(System-On-Chip)을 테스트 하는 동안 소모하는 전력소모는 SoC내의 IP 코어가 증가됨에 따라 매우 중요한 요소가 되었다. 본 논문에서는 Scan Latch Reordering과 Clock Gating 기법을 적용하여 scan-in 전력소모를 줄이는 알고리즘을 제안한다. Scan vector들의 해밍거리를 최소로 하는 새로운 Scan Latch Reordering을 적용하였으며 Gated scan 셀을 사용하여 저전력을 구현하였다. ISCAS 89 벤치마크 회로에 적용하여 실험한 결과 모든 회로에 대하여 향상된 전력소모를 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.700-702
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• 2005

The most electrical apparatus should be able to withstand short-time current and peak current during a specified short time until circuit breakers have interrupted fault current. It defines the short-time withstand ability of electric a apparatus to be remain for a time interval under high fault current conditions. It is specified by both dynamic ability and thermal capability. KERI(Korea Electrotechlology Research Institute) recently constructed the new short-time current and low voltage short circuit testing facilities. This paper shows short- circuit calculation of transformer and describes high current measuring system, and evaluate the result of short-time withstand test used in $3{\phi}$ 90MVA short-time current testing facilities.

• 비파괴검사학회지
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• 제24권4호
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• pp.371-377
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• 2004

원자력 발전소의 터빈에서 운전 연수 증가에 따라 pin finger형 블레이드 루트부에 균열이 발생하는 문제점이 발생되었다. 블레이드 루트부에 대한 비파괴검사는 매 계획 예방 정비기간 동안 수동 초음파 검사를 통하여 수행되어 왔으나, 검사의 신뢰성을 확보하기 위해 해당 설비에 대한 자동 초음파 검사 기술 개발의 필요성이 대두되었으며, 이에 따라 자동 초음파 검사 장비 및 검사 기술을 개발하였다. 개발된 검사 장비의 적용성을 확인하기 위해 계획 예방 정비 기간 중 저압터빈 2, 3단 블레이드 루트부에 대한 자동 초음파 검사를 수행하고, 다양한 형태의 터빈 검사에 확대 적용 가능성을 확인하였다.

• 전기학회논문지
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• 제64권1호
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• pp.196-200
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• 2015

The switching noise in the power electronics of the power conversion equipment (Power Conditioning System) for large energy storage devices are generated. Since the burst-level transient noise from being generated in the power system at a higher power change process influences the control circuit of the low voltage driver circuit. Noise may cause the malfunction of the control device even if no dielectric breakdown leads to a control circuit. To overcome this, this paper proposes the installation of an additional nano-surge protection device on the power supply DC output circuit of the battery management unit.

• 전력전자학회논문지
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• 제17권5호
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• pp.431-437
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• 2012

PV simulators are essential equipment for testing power conditioning systems (PCS) which are one of an important part in PV generator systems, for testing before shipment. High dynamic PV simulator is required since MPPT(Maximum Power Point Tracking) test procedure has been established by EN50530 regulation recently. Most high quality PV simulator prevailed in the market is linear type which however has low efficiency. This paper proposes design guide lines for the power stage and LCL type filter cooperating with a switching mode PV simulator that shows high efficiency and very low power consumption. Proposed theory is verified by experiment.

• 한국산업융합학회 논문집
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• 제25권3호
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• pp.379-386
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• 2022

The goal of this research is to verify a performance test system for a low speed, high torque, and harsh reducer at low cost. The reducer rotates a cooling fan with a diameter of 10 meters, in a high temperature (50℃) cooling tower in a geothermal power plant. It requires about 500 kgf·m torque and 47.75 kW power to rotate the fan at a maximum power condition. An expensive dynamometer is commonly used for performance test of a motor or a reducer. In this paper, a low cost system is developed using a hydraulic pump as a load unit to generate torque instead of a dynamometer. We accurately calculated the required power, the flow meter, and the pressure of the pump, and selected to design and optimize the system at minimal cost. The system also applied another reverse reducer and a gearbox to increase the rotational speed and to reduce the torque from the low speed and high torque target reducer. This allows low-cost systems to be built using inexpensive components. The developed system was able to successfully measure the high torque and the low rotational speed of the target reducer at high temperature.

• 비파괴검사학회지
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• 제26권4호
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• pp.231-238
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• 2006

위상 배열 초음파 기법을 이용한 국내 표준형 윈전 저압 터빈의 디스크 검사에 대하여 연구하였다. 이를 위하여 디스크 mockup을 제작하고 결함을 가공하였으며 결함에 대한 검출과 길이 측정 방법에 따른 결과를 고찰하였다. 깊이 측정에서 릴은 결함은 AATT(absolute arrival time technique)방법 혹은 RATT (relative arrival time technique)방법을 사용하여 깊이를 측정할 수 있었으나, 조기에 발견하여야 할 깊이가 깊지 않은 결함은 이와 같은 방법으로 깊이를 측정할 수 없었다. 이 경우 결함 신호가 나타나는 각도 범위를 이용하여 결함 깊이를 측정하였으며 유용한 도구임을 확인하였다.

• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.16-22
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• 2010

Cast austenitic stainless steel(CASS) is used in the primary cooling piping system of nuclear power plant for it's relative low cost, corrosion resistance and easy of welding. However, the coarse-grain structure of cast austenitic stainless steel can strongly affect the inspectability of ultrasonic testing. The major problems encountered during inspection are beam skewing, high attenuation and high background noise of CASS component. So far, the best inspection performance involving CASS components have been achieved using low frequency TRL(Transmitter/Receiver side-by-side L wave) angle beam probe. But TRL technique could not detect shallow defect and it contains an uncertainty for sizing capability. Currently, most of researchers are studying to overcome these challenge issue. In this study, low-frequency phased array TRL technique used to detect and sizing the flaws in CF8A cast austenitic stainless steel.As conclusion, we could detect and size not only axial flaw but also circumferential flaw using low frequency phased array technique.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2310-2312
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• 2004

In Korea Electric Power Corporation (or KEPCO), several Demand-Side Management (or DSM) program have been carried out to effectively meet electric power demand at least costs by modifying customers electricity use patterns. As one of them, KEPCO applies low-priced night thermal-storage power service for heat appliances to facilitate efficient use of power facilities by shifting relatively high daytime demands to night hours to build loads during the off-peak periods. In the market of heat-storage type water-heater, electric water-heater has been mostly used, but it has low energy efficiency and needs high capacity electric equipments. So in order to replace these electric water heaters, 15 HP air-source heat pump water heater is developed in Korea Electric Research Institute (or KEPRI). This paper shows that measurement system for performance testing of heat pump water heater is established and heating capacity and performance is analyzed and measured for out-door environmental change.

• ETRI Journal
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• 제30권3호
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• pp.412-420
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• 2008

A new scan partition architecture to reduce both the average and peak power dissipation during scan testing is proposed for low-power embedded systems. In scan-based testing, due to the extremely high switching activity during the scan shift operation, the power consumption increases considerably. In addition, the reduced correlation between consecutive test patterns may increase the power consumed during the capture cycle. In the proposed architecture, only a subset of scan cells is loaded with test stimulus and captured with test responses by freezing the remaining scan cells according to the spectrum of unspecified bits in the test cubes. To optimize the proposed process, a novel graph-based heuristic to partition the scan chain into several segments and a technique to increase the number of don't cares in the given test set have been developed. Experimental results on large ISCAS89 benchmark circuits show that the proposed technique, compared to the traditional full scan scheme, can reduce both the average switching activities and the average peak switching activities by 92.37% and 41.21%, respectively.