• Korean Journal of Materials Research
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• v.7 no.11
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• pp.974-980
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• 1997

SiC$_{p}$/AI 합금 복합재료에 있어서 동적 및 정적파괴인성시험을 실시하고 파괴거동에 미치는 부하조건의 영향을 검토하였다. 동적파괴인성시험은 CAI시스템을 이용하여 1.5m/sec의 부하속도로 실시하였고, 정적파괴인성시험은 만능시험기를 이용하여 0.3 mm/min의 부하속도로 실시하였다. 또한 파괴과정을 명확히 해석하기 위하여 동적부하조건에 대해서는 stop block법을, 정적부하조건에 대해서는 복수시험편법을 이용하였다. 균열의 발생 및 성장은 부하조건에 의해 크게 영향을 받으며, 변위량에 대한 균열의 발생은 정적부하조건에서 더 빨리 일어나고, 균열의 성장은 동적부하조건에서 더 급격하다. 또한 부하조건은 파괴의 형태에도 크게 영향을 미치며, 동적부하조건하에서는 정적부하조건하에 비하여 균열이 입자부분(입자의 파단 또는 박리)을통과해 가는 경향이 크고 비교적 많은 편향을 반복해서 진행해 가지 때문에 파괴인성치도 크다.다.

• Journal of Energy Engineering
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• v.4 no.3
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• pp.387-393
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• 1995

본 연구에서는 단기 전력수요예측에 있어서 필요한 데이터의 수와 계산시간을 경감하면서 보다 정확성을 기할 수 있는 앨고리즘의 개발을 위하여 이에 적합한 칼만필터링 앨고리즘을 고찰하였다. 또한 칼만필터 앨고리즘을 토대로 필터의 모형화를 통하여 단기 전력수요를 예측할 수 있는 실시간 동적예측 모형을 구축하고 그 적용 가능성을 시험하였다.

• 연구논문집
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• s.34
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• pp.47-58
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• 2004

Power plants rely on air operated valves for the proper operation of many plant system. Many significant problems arise in vital systems of power plants due to air operated valve failures. This paper deals with the diagnosis technique and data acquisition method of an AOV actuator peformance. We constructed AOV diagnosis system and performed some tests to find out whether an AOV actuator was properly designed.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.6
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• pp.35-41
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• 2007

The rate of loading in motor operated valve(MOV) can be defined as a variation of correlation between the actuator torque and the thrust upon the variation of operating load. This paper contains the analysis of characteristic and the validity of loading rate in the opening stroke of gate type motor operated valve. Also, this paper describes the evaluation result of loading rate for 40 MOVs' opening stroke using newly derived methodology in this study. Author has found a result that loading rate of opening stroke gets a negative value when the differential pressure is higher than 150 psi and this value goes up depending on the amount of the differential pressure.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.2
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• pp.100-105
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• 2011

By adopting HIL(Hardware-in-the-Loop), component characteristics in vehicle environment can be obtained without implementing component in the vehicle. In this paper, when specific motor is adopted as traction motor in hybrid electric vehicle HIL implementation procedures are explained. In order to implement HIL method motor testing. vehicle performance simulator and load characteristic are explained. Vehicle controller used in simulator is directly uploaded in real controller. Especially as a load dynamometer actively controlled motor system is used without connecting conventional mechanical inertia. Motor characteristics are obtained using HIL implementation when test motor is used as a traction motor for parallel hybrid electric vehicle. Proposed method can be used as experimental equipment to educate driving characteristics of hybrid electric vehicle.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.331-334
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• 2010

Operating characteristics of DGT-5 being developed by Doosan Heavy Industries & Construction Co., Ltd. for power generation service was evaluated. Starting behavior was improved by a series of tests to investigate the effect of various fuel schedule and several combination of bleed valve control. The engine showed stable operation without any instability of compressor in the full operating regime covering from start-up to load conditions. If there is a rapid change of load in the condition of synchronization to Grid, the engine can be controlled stably based on the analysis of dynamic responses of the engine to an rapid load change and a sudden load rejection.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.70-71
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• 2013

PV Simulator는 태양광발전용 Power Conditioning System (PCS)을 개발하거나 제품 출하 시 성능을 시험하기 위하여 필요한 장비이다. 본 논문에서는 3상 PWM 컨버터로 안정된 직류전압원을 확보하고, 3대의 DC-DC 컨버터에 의하여 각각의 PV array에 대한 I-V 특성을 독립적으로 모사할 수 있는 구조의 PV Simulator를 제안한다. 제안된 PV Simulator의 동적 성능을 확보하기 위하여는 DC-DC 컨버터에서 요구하는 순간적인 전류 외란에 대하여 강인하고 안정적인 DC전압을 공급해주는 3상 PWM 컨버터의 성능이 요구된다. 본 논문에서는 부하전류의 외란에 대한 3상 PWM 컨버터의 전압응답 특성을 분석하고, 외란에 강인한 제어기를 설계하고 제어게인을 선정한다. 시뮬레이션과 실험을 통하여 제안된 제어기의 성능이 우수함을 검증한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.328-341
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• 2017

In the control actuator system of a launch vehicle based on thrust vectoring, the interaction between electro-mechanical position servo and inertial load are combined with the dynamic characteristics of the flexible vehicle support to generate synthetic resonance. This occurred resonance is fed back to the attitude control system and can influence stability of launch vehicle. In this study, we proposed a simulation model to analyze synthetic resonance of electro-mechanical actuation system for thrust vector control and explained the results of simulation and test using dynamic force feedback control which improves dynamic characteristics of servo actuation system by reducing synthetic resonance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2739-2746
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• 2011

This paper proposes the method for more effectively calculating X/R which is the ratio of equivalent reactance(X) and resistance(R) of the bulk power system and analyses the characteristic of X/R values by applying the proposed method to the real bulk power systems. X/R is used to determine the rating of the relay in the bulk power systems and its value has been accepted to be big enough to ignore the equivalent resistance of the bulk power systems. However, X/R is calculated as a big number when only the upper transformer and transmission line are considered. The correct approach to calculating X/R needs to consider all the parameters including generators, transformers, lines and loads. This paper calculates X/R of the bulk power systems using dynamic models which have been used to analyse the power system stability. The effectiveness of the proposed method is verified by applying it to the test system and X/R values of the real bulk power systems are analyzed. In addition, the dependence of X/R on the closeness of its calculating locations to the generator is verified by using the marginal loss factor which has been used in the electricity market.