• 제목/요약/키워드: Reliability improvement

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배전계통의 신뢰도 향상을 위한 분산형전원의 설치 및 운영 (Placement and Operation of DG System for Reliability Improvement in Distribution Systems)

  • 김규호;이상근;김진오;김태균;전동훈;차승태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 A
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    • pp.348-350
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    • 2004
  • This paper presents the scheme for reliability improvement by dispersed generation system (US) installation and operation in distribution systems. The objective functions such as power losses cost, operation cost of DGS, power buy cost and interruption cost are minimized for reliability improvement. The original objective functions and constraints are transformed into the equivalent multiple objective functions with fuzzy sets to evaluate their imprecise nature. The several indices for reliability evaluation are improved by dispersed generation system installation.

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교환기의 신뢰도에 관한 소고

  • 최태구;이대기
    • ETRI Journal
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    • 제5권4호
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    • pp.30-34
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    • 1983
  • This paper presents some considerations of reliability for switching system, i. e. reliability measures, reliability model and prediction, and reliability improvement. Those are described comprehensively than technologies aspects. Recent trends for switching system reliability are also described so as to aid people interested in this field.

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Study of electric vehicle battery reliability improvement

  • Ismail, A.;Jung, W.;Ariffin, M.F.;Noor, S.A.
    • International Journal of Reliability and Applications
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    • 제12권2호
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    • pp.123-129
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    • 2011
  • Due to restriction of vehicle emissions and high demand for fossil fuels nowadays, car manufacturers around the world are looking into alternative ways in introducing new car model that would vastly captured the market. Thus, Electric Vehicle (EV) has been further developed to take the advantage of the current global issues on price of fossil fuels and impact on the environment. Since car battery plays the crucial role on the overall performance of EV, many researchers have been working on improving the component. This paper focused on the reliability of EV battery which involves recognizing failure types, testing method and life prediction method. By focusing on these elements, the reliability feature being identified and as a result the batteries life will be prolonged.

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Three extended geometric process models for modeling reliability deterioration and improvement

  • Jiang, R.
    • International Journal of Reliability and Applications
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    • 제12권1호
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    • pp.49-60
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    • 2011
  • The geometric process (GP) has been widely used for modeling failure and repair time sequences of repairable systems. The GP is mathematically tractable but restrictive in reliability applications since it actually assumes that the mean function of inter-failure times sequence asymptotically decreases to zero; and the mean function of successive repair times sequence asymptotically increases to infinity. This is generally unrealistic from an engineering perspective. This paper presents three extended GP models for modeling reliability deterioration and improvement (or growth) process. The extensions maintain the advantage of mathematical tractability of GP model. Their usefulness and appropriateness are illustrated with three real-world examples.

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산업용차량 고무마운트 부품에 대한 내구성 및 신뢰성개선 (Durability and Reliability Improvement for the Rubber Mount of Industrial Trucks)

  • 정원
    • 산업경영시스템학회지
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    • 제30권3호
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    • pp.127-134
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    • 2007
  • Predicting fatigue life of rubber components is an important issue in design procedure for industrial trucks to assure the durability and reliability. Main considerations in designing rubber components against fatigue failure are the compounding technology, shape design, and manufacturing process. Among them the rubber compounding technology is one of the most critical factor to determine more than 50% of component's quality. This paper presents how to improve the durability and reliability of industrial rubber mount during its design, development and prototype testing. The data presented illustrates explicitly the prediction of reliability growth in the product development cycle. The application of these techniques is a part of the product assurance function that plays an important role in rubber components reliability improvement.

초전도 한류기 적용시 배전계통의 신뢰도 비용 평가 (Reliability Cost Evaluation of Power Distribution System with Superconducting Fault Current Limiter)

  • 문종필
    • 전기학회논문지P
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    • 제63권4호
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    • pp.266-270
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    • 2014
  • In this paper, the effects of superconducting fault current limiter (SFCL) installed in power distribution system on reliability are evaluated and analyzed. The fault current will be decreased in power distribution system with SFCL because of the increased impedance of SFCL. The decreased fault current will improve the voltage drop of the bus of substation. The voltage drop is an important factor of power distribution system reliability. In this paper, improvement of reliability worth is analyzed when SFCLs are installed at the starting point in power distribution system. First, resistor-type SFCL model is used in PSCAD/EMTDC. Next, typical power distribution system is modeled. Finally, when the SFCLs with impedance 0.5 [${\Omega}$] are installed in feeder, power distribution system reliability is evaluated. Also, the improvement effect of reliability worth including the effect of voltage sag is analyzed using customer interruption cost according to whether or not SFCL is installed.

프로세스 품질 개선과 셋업 절감을 고려한 연속 및 불연속 배송 환경에서의 최적 불완전 품질 재고 모형 (Optimal Imperfect-Quality Inventory Models for Continuous and Discrete Shipping with Process Improvement and Setup Reduction)

  • 김대수;유승호
    • 한국경영과학회지
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    • 제34권1호
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    • pp.11-28
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    • 2009
  • Intelligent investment in setup cost reduction and process reliability improvement is crucial to an emerging integrated lean six sigma practice today. This study examines a cost-minimizing problem of jointly determining production lot size, setup cost reduction, and process reliability improvement decisions for a manufacturer with an imperfect production process. We develop models for previously untapped discrete shipping in a supply chain context as well as continuous shipping and solve them optimally using differential calculus and nonlinear programming. We also conduct analytic and numerical sensitivity analyses to provide various important managerial insights into practices.

무기체계 RAM 목표값 설정 관련 개선방안 고찰 (A Study on the Improvement of RAM Objective Considering Method for Weapon System)

  • 황경환;허장욱
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제17권2호
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    • pp.150-158
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    • 2017
  • Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

CBM기반의 고장 예측 신뢰성 모델 (Failure Prediction Reliability Model based on the Condition-based Maintenance)

  • 김연수;정영배
    • 산업경영시스템학회지
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    • 제22권52호
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    • pp.171-180
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    • 1999
  • Industrial equipment reliability improvement and maintenance is gaining attention as the next great opportunity for manufacturing productivity improvement. Reactive maintenance is expensive because of extensive unplanned downtime and damage to machinery. To avoid such an unplanned machine downtime, it is needed to use proactive maintenance approach by either using historical maintenance data or by sensing machine conditions. This paper discusses failure diagonosis and prediction based on the condition-based maintenance and reliability technique. Thus, by enabling such a framework, it can bring us more efficient planning and execution of maintenance to reduce costs and/or increase profits.

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