• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.7-11
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• 2017

This paper describes a design concept of NPC1 power stack for 1500VDC megawatt level solar inverter. This stack uses three latest half-bridge IGBT modules with highest power density and operation junction temperature, which enable realization of power level beyond 1MW without paralleling. Critical design concept on loop inductance is explained. Dynamic characteristics are verified by double-pulse test. Thermal characteristics and output power limits are verified by thermal test. Temperature-sensitive component on PCB as output power constraint is identified. Different PCB repositioning solutions are tested to give the overall output power thermal derating curves, which enable output power of 1.15MW at $T_A=55^{\circ}C$ with $15^{\circ}C$ thermal margin. The power stack characteristic and performance change under different thermal environment is further analyzed.

• 항공우주시스템공학회지
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• 제12권1호
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• pp.57-67
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• 2018

APD (Antenna Pointing Driver)는 차세대 중형위성에 탑재되는 위성 데이터 전송용 2축 짐벌식 X-밴드 안테나를 구동하기 위한 전장품이다. 전장품에 탑재된 EEE (Electrical, Electronic and Electromechanical) 소자의 열소산은 소자의 효율과 수명, 신뢰도에 직접적으로 영향을 미치게 되며, 종국에는 소자 자체의 파손으로 위성 전체 시스템의 실패를 초래할 수 있다. 임무기간동안 전장품의 신뢰성을 보장하기 위해 EEE 소자의 접합온도는 중요한 설계요소가 되며, 허용범위 내에서 확보되어야 한다. 따라서 사전에 소자의 감쇄비를 고려한 열해석이 반드시 수행되어야하며, 이를 위해 적절한 열해석모델을 구축하여야한다. 본 논문에서는 APD의 온도 요구조건 만족여부를 확인하기 위해 열설계 및 열해석을 수행하였으며, 이와 더불어 각 모델링 기법에 따른 열해석모델의 유효성을 비교, 분석하였다.

• 전력전자학회논문지
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• 제4권2호
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• pp.122-127
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• 1999

본 논문에서는 3마력의 컴프레샤 모터를 갖는 대용량의 인버터 에어컨의 원가절감과 성능향상을 위해서 병렬구동방식을 사용한 역률제어회로를 제안하였다. 역률개선 LC필터를 제거하고 출력캐패시터와 인버터 스위치의 정격축소를 통해서 재료비를 줄이기 위해서 적절한 설계절차를 제시하였다. 이렇게 결정된 소자를 사용하여 6[kW] 소지전력을 갖는 프로토형 회로를 구성하고 제안된 회로의 동작을 확인하기 위해서 실험을 하였다.

• 한국항공운항학회지
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• 제18권4호
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• pp.38-43
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• 2010

A continuing challenge in the aviation industry is how to safely keep aircraft in service longer with limited maintenance budgets. Therefore, all the advanced countries in aircraft technologies put great efforts in prediction of failure rate in parts and system, but in the domestic aircraft industry is lack of theoretical and experimental research. Prediction of failure rate provides a rational basis for design decisions such as the choice of part quality levels and derating factors to be applied. For these reasons, analytic prediction of failure rate is essential process in developing aircraft structure. In this paper, a procedure for prediction of failure rate for aircraft structural parts is presented. Cargo door kinematic parts are taken to illustrate the process, in which the failure rate for Hook part is computed by using Monte Carlo Simulation along with Response Surface Model, and system failure rate is obtained afterwards.

• 한국압력기기공학회 논문집
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• 제19권1호
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• pp.27-35
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• 2023

Pressure tubes are the main components of PHWR core and serve as the pressure boundary of the primary heat transport system. However, because pressure tubes have changed their geometrical dimensions under the severe operating conditions of high temperature, high pressure and neutron irradiation according to the increase of operation time, all dimensional changes should be predicted to ensure that dimensions remain within the allowable design ranges during the operation. Among the deformations, the diameter expansion due to creep leads to the increase of bypass flow which may not contribute to the fuel cooling, the decrease of critical channel power and finally the deration of the power to maintain the operational safety margin. This study is focused on the modeling of the expansion of the pressure tube diameter based on the operating conditions and measured diameter data. The pressure tube diameter expansion was modeled using the neutron flux and temperature distributions of each fuel channel and each fuel bundle as well as the measured diameter data. Although the basic concept of the current modeling approach is simple, the diameter prediction results using the developed methodology showed very good agreement with the real data, compared to the existing methodology.