• 한국농공학회지
• /
• 제37권E호
• /
• pp.1-9
• /
• 1995

It is shown that two step power transformation is more efficient for the normalization of frequency distribution with the coefficient of skewness of zero in comparison with others including SMEMAX and power transformations. It is confirmed that the design low flows calculated using power and two step power transformations used in this study are generally nearer to the observed data as compared with those of SMEMAX transformation at all return periods in the applied watersheds of the Kum, Naktong and Yongsan rivers in Korea.

• Journal of Power Electronics
• /
• 제11권5호
• /
• pp.734-742
• /
• 2011

In this paper a robust method is presented for the combined design of STATCOM and Power System Stabilizer (PSS) controllers in order to enhance the damping of the low frequency oscillations in power systems. The combined design problems among PSS and STATCOM internal ac and dc voltage controllers has been taken into consideration. The equations that describe the proposed system have been linearized and a Fuzzy Logic Controller (FLC) has been designed for the PSS. Then, the Particle Swarm Optimization technique (PSO) which has a strong ability to find the most optimistic results is employed to search for the optimal STATCOM controller parameters. The proposed controllers are evaluated on a single machine infinite bus power system with the STATCOM installed in the midpoint of the transmission line. The results analysis reveals that the combined design has an excellent capability in damping a power system's low frequency oscillations, and that it greatly enhances the dynamic stability of power systems. Moreover, a system performance analysis under different operating conditions and some performance indices studies show the effectiveness of the combined design.

• Nuclear Engineering and Technology
• /
• 제55권5호
• /
• pp.1901-1910
• /
• 2023

The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved.

• 에너지공학
• /
• 제25권1호
• /
• pp.108-112
• /
• 2016

본 연구에서는 국내 원전 산업의 데이터 기반 설계기법 전환을 위하여 관련 문헌을 조사하고 데이터 기반 설계기술에 대한 개념을 정립하였다. 또한 국내외 원전 산업 기술동향 분석을 통해 데이터 기반 설계통합시스템 Framework 개발 및 관련 주요기능을 도출하였다. 국내 원전 건설 시 최신 설계통합시스템 적용에 따라 이를 활용하는 제작사, 시공사 및 발주자의 업무수행 방식 또한 전면적인 전환을 위한 원전 건설단계별 업무프로세스 개선방향을 도출하였다. 이는 기자재 3D 모델 통합, 3D CAD 모델생성, 시공검토 Simulation 등 모델기반 현장설계 수행이 가능하며, 현장설계에서 발생하는 모든 설계도면 및 관련 정보가 데이터 기반 3D CAD 시스템으로 통합관리가 가능하여 이를 운영단계에 이관하여 O&M 단계에서 데이터 기반 운영체계가 가능함에 따라 발전소 안전 운영에 향상이 기대된다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.480-484
• /
• 2000

The pole placement technique for control design of the current mode controlled DC-DC switchmode power converter is proposed. It is compared with conventional transfer function analysis. Using the pole placement technique control design automation algorithm, by computer-based tool is presented. Control design example with large signal simulation is shown.

• 항공우주시스템공학회지
• /
• 제8권1호
• /
• pp.42-47
• /
• 2014

The role of Electrical Power Subsystem (EPS) is to generate a power and distribute it to the electrical devices for the system operation. For on-orbit operation of cube satellite, it is also necessary to supply power to on-board mission devices as commercial satellite does. Recently, commercial EPS products dedicated for the cube satellite application has been developed and widely used for the power subsystem design. In this paper, a permanent magnet attitude stabilization method without external power has been introduced because it has advantage from power consumption point of view and the EPS design of cube satellite by applying the commercial EPS products has been introduced and investigated. This paper also deals with the specification of the commercial EPS products for the beginner of the cube satellite design.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
• /
• pp.15-17
• /
• 2013

In the design of combined cycle power plants, the design parameters considered mainly could be changed and added for performance evaluation with change on the design objective and method. Therefore, the design criteria considering the different objectives and type of power plant were needed. Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants with demand on generation of power and heat and carbon capture system from high pressure flue gas have been performed to establish criteria for optimization of power plants.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1756-1758
• /
• 2005

This paper deals with the power conversion and design of permanent magnet generator for wind power applications. This paper derives analytical solutions for open-circuit field, armature reaction field, torque, back-emf, inductance and resistance of permanent magnet generators for wind power applications. And then, by presenting the variation of torque according to design parameters and by applying restrict conditions to it, we determine proper design parameter appropriate to rated power and speed. Finally, this paper also presents power conversion system resonable in wind power applications.

• KEPCO Journal on Electric Power and Energy
• /
• 제5권3호
• /
• pp.181-188
• /
• 2019

본 연구에서는 발전시스템의 설계 입출력변수들을 Heat & Mass balance 계산 solver 및 최적화 알고리즘과 연계하고 반복계산 과정을 자동화함으로써 기술 및 경제적 측면을 고려한 최적의 발전시스템 Heat & Mass balance 설계를 도출하는 최적설계 자동화 기법을 개발하였다. 그리고 이에 대한 효과를 분석하기 위하여 발전소 형식별 10종에 대하여 최적설계 기법을 적용한 결과, NPV 및 IRR에 대한 개선 효과를 기대할 수 있었다.

• Journal of Biosystems Engineering
• /
• 제22권2호
• /
• pp.105-116
• /
• 1997

Using the design variables and conditions reported in the rut part of this paper, an analysis and optimum design of the tractor-rotary power driveline were carried out. The optimum design method involved 1 variable, 2 variable and multiple variable analysis performed as requested in the design process. In order to evaluate the effects of the design variables on the power transmission performance a sensitivity analysis were also conducted. the results indicated that the length and link point of the upper link, the upper hitch point of the implement master and the location of the implement input connection affect most significantly the driveline performance. The optimum design improved the performance of an exampled tractor-rotary driveline by 93% in terms of cosine ratio.