• Journal of the Korean Institute of Gas
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• v.23 no.5
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• pp.1-7
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• 2019

Although the rupture pressure is evaluated from remaining strength when a flaw is defected to cylinder surface, but the rupture pressure can be not easy to estimate for the composite cylinders. In this study, the area capacity method is developed for the type-3 cylinders that is based on the result applied area capacity method of type-1 cylinders. And the reliability is validated by bursting test with artificial flaw at the cylinder surface. The predicted data of area capacity method and experimental results have very similar tendency. This method and results will be a very important records in field of rupture pressure estimations.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.265-270
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• 1997

Helical gear system is utilized to transmit motion between parallel shafts. The axial thrust loads on the shafts are existed. On each of the support shafts, at least one of the bearings should be able to support the axial loads. The reliability and life analysis are based on the two-parameter Weibull distribution lives of the component gears and bearings. The computer calculates the system lives and dynamic capacities of the components and their system. The system life is defined as the life of the component or the helical gear system at an output torque at which the probability of survival is ninety percent.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2171-2172
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• 2011

Recently, while interests on supply of electric vehicles have increased there still are insufficient charging facilities. As a solution to this matter, using electric power grids that constantly retain about 30~50[%] residual power is being considered. Therefore proposed in this paper railway, is a method to establish a charging infrastructure to utilize railway DC power grids. In addition we designed a high-speed DC charging system, and simulated improvements of the charging structure's charging efficiency according to remaining capacity of batteries.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.423-426
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• 1996

The conditions to be satisfied with SOC(State-of-Charge) indicator installed on the electric vehicle were that it should be used under frequent loading conditions and that it should enable the monitor to adjust to the aging effect. But, the state-of-charge test requires a lengthy stabilization period after discharge cycles and the ampere-hour test requires the knowledge of the battery capacity in terms of amp-hours. However, a monitoring technique combining the state-of-charge test to enable the monitor to adjust to the aging effect with the ampere-hour test to use under frequent loading condition is studied and implemented on a microcontroller-based circuit in this paper. Specially, optical fiber is used to realize hydrometer which is immune to electromagnetic interference and toxic environment and makes it possible to be used in a wide temperature range.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.507-508
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• 2015

본 논문은 독립형 마이크로그리드의 운용을 위한 에너지관리전략(Energy Management Strategy)을 제안한다. 제안한 에너지관리전략은 독립형 마이크로그리드의 안정적인 운영을 위하여 신재생에너지의 발전량과 전체 부하량을 비교한 뒤 에너지저장장치(ESS, Energy Storage System)의 충전 및 방전을 결정한다. 또한 에너지저장장치의 잔존용량(SOC, State of Charge)에 따라 과충전/과방전을 예방하기 위하여 부하 차단, 분산전원의 운전 방식 및 디젤발전기의 발전을 제어하는 형태로 구성된다. 가상의 독립형 마이크로그리드를 구성하고 시뮬레이션을 진행하여 에너지관리전략의 적용 시 성능을 검증한다.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.175-179
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• 2000

A combustion project was completed regarding the development of a high-flow-rate purge burner in cooperation with three city gas companies(Pusan, Taegu, Samchulli). The project, started in May 1991, aimed at purging the line-packed-gas safely and quickly before getting into gas pipe working or relocation. According to the results, the purging noise is less than 80dB due to silencer screen. multi-nozzle and outlet inserted tube employed. In addition, the developed burner shows an increased work efficiency of 40-50% more as compared to the performance of conventional purge equipments. The project result is regarded as the first high-flow-rate purge burner developed within Korea. contributing to shortening purge hours, safe field work and easiness of purge site selection.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.415-416
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• 2014

FCEV(Fuel Cell Electric Vehicle)는 연료전지를 사용하여 차량 구동용 전동기에 필요한 에너지를 공급한다. 연료전지는 부하에 급격한 변화가 발생하였을 시에 과도특성이 나타나고 자동차에 에너지를 공급하는 속도에 영향을 준다. 그러므로 연료전지의 특성상 FCEV에서 배터리는 연료전지와 함께 사용된다. FCEV 및 전기자동차는 배터리의 대용량화를 위해 일반적으로 배터리 셀을 직/병렬로 모듈화하여 사용하는데, 이때 배터리 모듈의 충전 및 방전이 반복될 경우, 각 배터리 잔존용량의 불균형이 나타난다. 본 논문은 연료전지 전기자동차용 전력변환 장치를 이용하여 배터리 셀을 모듈화하여 모듈 별 밸런싱을 수행하는 시스템의 설계와 제어기법을 제안한다. 각각의 배터리 모듈과 연료전지를 연결하는 컨버터 모듈은 독립적으로 제어되어 배터리를 모듈 단위로 균등화시킨다. 이때 연료전지를 입력으로 절연형 컨버터를 병렬로 사용하며, 각각의 배터리 모듈을 균일하게 충전한다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.461-462
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• 2014

This paper proposes parallel operation method of single phase UPS module considering the battery SOC. A master module performs output voltage control and current sharing algorithm considering battery SOC of each UPS modules. The slave modules control output current by current reference from master module. The applied parallel operation method is verified by the PSIM simulation.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.413-414
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• 2012

본 논문에서는 C-rate, 온도, SOC (State-of-Charge, 잔존용량)를 고려하여 NiMH 배터리를 모델링하였고, 시뮬레이션 결과를 배터리 실험 결과와 비교하였다. 제안한 배터리 모델은 1차 테브난 등가회로를 기반으로 구성하였으며 Matlab/Simulink 환경에서 구현하였다. 모델을 구현하기 위한 실험으로는 정전류, 펄스전류 실험을 하여 가변온도와 다양한 C-rate에서 변하는 파라미터를 도출하였고, 도출한 파라미터는 룩업 테이블을 이용하여 배터리 모델에 적용하였다. 제안된 배터리 모델을 짧은 시간동안 불규칙하게 변하는 전류 패턴에 대한 시뮬레이션과 실험 파형을 통하여 배터리 모델의 성능을 검증하였다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2187-2189
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• 2001

The proposed algorithm has produced the rules of relationship between the load voltage, current, discharging electric power and ampere-hours, electric power capacity of battery on the basis of the data. Which were acquired through the battery discharging experiment that is defined by the battery's ambient temperature and various load conditions. Especially, by calculating the parameter of second order polynomial equation relation between the remaining capacity and the electric power, the algorithm is proposed adapting for the discharging pattern. And as the depth of discharging is increasing, the calculation-method of electric power is applied to decrease the accumulated error in the calculation method of capacity accumulation. Also, the proposed algorithm has compensated the temperature considering the capacity change of battery to the temperature.