• 제목/요약/키워드: Probabilistic Evaluation

검색결과 553건 처리시간 0.032초

차체 구조물의 확률론적 피로수명 평가 연구 (Probabilistic Fatigue Life Evaluation for a Car Body Structure)

  • 구병춘;서정원;김재훈
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.150-155
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    • 2002
  • En case of the fatigue life evaluation of rolling stock structures, mainly deterministic fatigue life evaluation has been carried out. But most of the parameters influencing on the fatigue life have a probabilistic distribution such as normal, log-normal, Weibull, etc. Therefore, to take probabilistic factors into fatigue life evaluation, probabilistic methods are being applied to the fatigue life evaluation of rolling stock. In this paper, probabilistic S-N analysis and methods using limit state functions are introduced. And some results of fatigue life evaluation obtained with these methods for rolling stock structures are shown.

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전압안정도를 고려한 확률론적 도달전력 산정에 관한 연구 (Probabilistic Arrival Power Evaluation considering Voltage Stability)

  • 문승필;장병훈;이재걸;최재석
    • 전기학회논문지
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    • 제59권8호
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    • pp.1366-1373
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    • 2010
  • Purpose of the electric power system planning and operation is to supply the electric energy to customers continuously and economically. With the mutual exclusive laws of nature between reliability and economic, finding the meeting point is very important but not easy. Commonly the probabilistic reliability indices of the electric power systems are represented with negatively. And the effectiveness of FACTS on the probabilistic reliability could not be reflected with common methods. In this paper, a method to evaluate the probabilistic arrival power at each load point is presented. With this new proposed method, probabilistic reserve margin at load points can be calculated and which can be used with positive reliability index also. Using the P-V analysis, the voltage stability is considered in reliability evaluation. It is expected that the proposed method will be useful expecially in reliability evaluation of electric power system which has voltage restriction.

신뢰도지수 및 몬데카를로 시뮬레이션을 이용한 원전 감육배관의 확률론적 손상역학 평가 (Probabilistic Damage Mechanics Assessment of Wall-Thinned Nuclear Piping Using Reliability Method and Monte-Carlo Simulation)

  • 이상민;윤강옥;장윤석;최재붕;김영진
    • 대한기계학회논문집A
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    • 제29권8호
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    • pp.1102-1108
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    • 2005
  • The integrity of nuclear piping systems has to be maintained sufficiently all the times during operation. In order to maintain the integrity, reliable assessment procedures including fracture mechanics analysis, etc, are required. Up to now, the integrity assessment has been performed using conventional deterministic approach even though there are lots of uncertainties to hinder a rational evaluation. In this respect, probabilistic approach is considered as an appropriate method for piping system evaluation. The objectives of this paper are to develop a probabilistic assessment program using reliability index and simulation technique and to estimate the damage probability of wall-thinned pipes in secondary systems. The probabilistic assessment program consists of three evaluation modules which are first order reliability method, second order reliability method and Monte Carlo simulation method. The developed program has been applied to evaluate damage probabilities of wall-thinned pipes subjected to internal pressure, global bending moment and combined loading. The sensitivity analysis results as well as prototypal evaluation results showed a promising applicability of the probabilistic integrity assessment program.

확률론적 파괴역학 기법을 이용한 압력관의 파손확률 평가 (Failure Probability Evaluation of Pressure Tube using the Probabilistic Fracture Mechanics)

  • 손종동;오동준
    • 한국안전학회지
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    • 제22권4호
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    • pp.7-12
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    • 2007
  • In order to evaluate the integrity of Zr-2.5Nb pressure tubes, probabilistic fracture mechanics(PFM) approach was employed. Failure assessment diagram(FAD), plastic collapses, and critical crack lengths(CCL) were used for evaluating the failure probability as failure criteria. The Kr-FAD as failure assessment diagram was used because fracture of pressure tubes occurred in brittle manner due to hydrogen embrittlement of material by deuterium fluence. The probabilistic integrity evaluation observed AECL procedures and used fracture toughness parameters of EPRI and recently announced theory. In conclusion, the probabilistic approach using the Kr-FAD made it possible to determine major failure criterion in the pressure tube integrity evaluation.

TRELSS를 이용한 전력계통의 확률론적 신뢰도 평가 VI - 송전망 확충계획시 응용에 관한 사례연구 - (Probabilistic Reliability Evaluation of Power System using TRELSS VI - Case Study on Transmission Line Planning -)

  • 김형철;트란트룽틴;최재석;전동훈;추진부;허연;한경남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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    • pp.78-82
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    • 2004
  • This paper suggests the power system reliability evaluation fur transmission lines planning in composite power systems. In recent the importance and necessity of some studies on reliability evaluation of grid comes from the recent black-out accidents occurred in the world. Since probabilistic criterion can reflect recognize the probabilistic nature of system components, the application of probabilistic criterion has received a lot of attention. This paper introduces features and operation modes of the Transmission Reliability Evaluation fur Large-Scale Systems(TRELSS) Version 6.2, a program made in EPRI, for assessing reliability indices of composite power system. The characteristics of the TRELSS program are illustrated by the case studies using the KEPCO system.

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순간정전을 고려한 배전계통에서의 신뢰도 평가-몬테카를로 방식의 적용 (Reliability Evaluation of Power Distribution Systems Considering the Momentary Interruptions-Application of Monte Carlo Method)

  • Sang-Yun Yun;Jae-Chul Kim
    • 대한전기학회논문지:전력기술부문A
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    • 제52권1호
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    • pp.9-16
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    • 2003
  • In this paper, we propose a reliability evaluation method considering the momentary interruptions of power distribution systems. The results of research are concentrated on two parts. One is the analytic and probabilistic reliability evaluation of power distribution system considering the momentary interruptions and the other is the reliability cost evaluation that unifies the cost of sustained and momentary interruptions. This proposed reliability cost evaluation methodology is also divided into the analytic and probabilistic approach and the time sequential Monte Carlo method is used for the probabilistic method. The proposed methods are tested using the modified RBTS (Roy Billinton Test System) form and historical reliability data of KEPCO (Korea Electric Power Corporation) system. Through the case studies, it is verified that the proposed reliability evaluation and its cost/worth assessment methodologies can be applied to the actual reliability studies.

Probabilistic seismic assessment of structures considering soil uncertainties

  • Hamidpour, Sara;Soltani, Masoud;Shabdin, Mojtaba
    • Earthquakes and Structures
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    • 제12권2호
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    • pp.165-175
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    • 2017
  • This paper studies soil properties uncertainty and its implementation in the seismic response evaluation of structures. For this, response sensitivity of two 4- and 12-story RC shear walls to the soil properties uncertainty by considering soil structure interaction (SSI) effects is investigated. Beam on Nonlinear Winkler Foundation (BNWF) model is used for shallow foundation modeling and the uncertainty of soil properties is expanded to the foundation stiffness and strength parameters variability. Monte Carlo (MC) simulation technique is employed for probabilistic evaluations. By investigating the probabilistic evaluation results it's observed that as the soil and foundation become stiffer, the soil uncertainty is found to be less important in influencing the response variability. On the other hand, the soil uncertainty becomes more important as the foundation-structure system is expected to experience nonlinear behavior to more sever degree. Since full This paper studies soil properties uncertainty and its implementation in the seismic response evaluation of structures. For this, response sensitivity of two 4- and 12-story RC shear walls to the soil properties uncertainty by considering soil structure interaction (SSI) effects is investigated. Beam on Nonlinear Winkler Foundation (BNWF) model is used for shallow foundation modeling and the uncertainty of soil properties is expanded to the foundation stiffness and strength parameters variability. Monte Carlo (MC) simulation technique is employed for probabilistic evaluations. By investigating the probabilistic evaluation results it's observed that as the soil and foundation become stiffer, the soil uncertainty is found to be less important in influencing the response variability. On the other hand, the soil uncertainty becomes more important as the foundation-structure system is expected to experience nonlinear behavior to more sever degree. Since full probabilistic analysis methods like MC commonly are very time consuming, the feasibility of simple approximate methods' application including First Order Second Moment (FOSM) method and ASCE41 proposed approach for the soil uncertainty considerations is investigated. By comparing the results of the approximate methods with the results obtained from MC, it's observed that the results of both FOSM and ASCE41 methods are in good agreement with the results of MC simulation technique and they show acceptable accuracy in predicting the response variability.

TRELSS를 이용한 우리나라 전력계통의 확률론적 신뢰도 평가에 관한 연구 (A Study on Probabilistic Reliability Evaluation of KEPCO System using TRELSS)

  • 전동훈;최재석;김건중
    • 대한전기학회논문지:전력기술부문A
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    • 제55권11호
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    • pp.453-462
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    • 2006
  • This paper evaluates the reliability of KEPCO system using TRELSS, which is a probabilistic reliability evaluation program for large-scaled power system. In order to reflect the characteristic of KEPCO system, the sensitivity of reliability indices such as LOLP, EDLC, EENS and Energy Curtailment for variations of TRELSS parameter and input data was analyzed. Additionally, probabilistic reliability of KEPCO system reflecting sensitivity analysis results was systematically evaluated and simulated. Finally, maximum acceptable FOR of KEPCO system to satisfy reliability criterion, which meet in process of establishing the basic plan for long-term electricity supply and demand is suggested.

한전 765kV 송전선로 확충계획의 확률론적 신뢰도 평가 (Probabilistic Reliability Evaluation for 765kV Transmission Lines of KEPCO Grid Expansion Planning)

  • 트란트룽틴;권중지;최재석;전동훈;한경남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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    • pp.237-239
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    • 2005
  • The importance and necessity conducting studies on grid reliability evaluation have been increasingly important in recent years due to the number of black-out events occurring through in the world. Quantity evaluation of transmission system reliability is very important in a competitive electricity environment. The reason is that the successful operation of electric power under a deregulated electricity market depends on transmission system reliability management. Also in Korea it takes places. This paper presents the probabilistic reliability evaluation for 765KV transmission lines of KEPCO grid expansion planning. The Transmission Reliability Evaluation for large-Scale Systems (TRElSS) Version 6.2, a software package developed by Electric Power Research Institute (EPRI) is utilized in determining the improved probabilistic reliability indices of (KEPCO) system.

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전압 크기의 품질 및 전력수요 변동모델을 고려한 배전계통의 통합적인 신뢰도 및 비용 평가 (Unified Reliability and Its Cost Evaluation in Power Distribution Systems Considering the Voltage Magnitude Quality and Demand Varying Load Model)

  • Yun, Sang-Yun
    • 대한전기학회논문지:전력기술부문A
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    • 제52권12호
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    • pp.705-712
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    • 2003
  • In this paper, we propose new unified methodologies of reliability and its cost evaluation in power distribution systems. The unified method means that the proposed reliability approaches consider both conventional evaluation factor, i.e. sustained interruptions and additional ones, i.e. momentary interruptions and voltage sags. Because the three voltage quality phenomena generally originate from the outages on distribution systems, the basic and additional reliability indices are summarized considering the fault clearing mechanism. The proposed unified method is divided into the reliability evaluation for calculating the reliability indices and reliability cost evaluation for assessing the damage of customer. The analytic and probabilistic methodologies are presented for each unified reliability and its cost evaluation. The time sequential Monte Carlo technique is used for the probabilistic method. The proposed DVL(Demand Varying Load) model is added to the reliability cost evaluation substituting the average load model. The proposed methods are tested using the modified RBTS(Roy Billinton Test System) form and historical reliability data of KEPCO(Korea Electric Power Corporation) system. The daily load profile of the each customer type in domestic are gathered for the DVL model. Through the case studies, it is verified that the proposed methods can be effectively applied to the distribution systems for more detail reliability assessment than conventional approaches.