4 research outputs found

    Stochastic Analysis and Performance Evaluation of a Complex Thermal Power Plant

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    This paper present the stochastic analysis and performance evaluation of the thermal power plant which serve as an improvement of Vora 2011, by the use of performance evaluation using probabilistic approach. The research study consists mainly three sub-systems namely boiler, super heater and re-heater connected in series configuration with two type of preventive maintenance ie offline and online. The analysis shows that as failure rate increases, the availability decreases and as repair rate increases, the availability of the system increases and vice-versa. Performance matrices shows that Super heater subsystem is the most critical subsystem among the three subsystems in the power generation plant as far as maintenance is concern, as its availability percentage is the least among the three subsystem and boiler subsystem is having the higher percentage of availability with about 99% level. The results of the analysis are found beneficial to the plant management for the availability analysis of the system. Key words: Reliability, Availability, Maintainability

    Impact of wind farms capacity factor and participation in frequency support – reliability analysis

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    Expanded integration of wind energy implies technical confronts to maintain system reliability. Thus, comprehensive reliability models for wind turbines and related features are required. Composite and precise wind farms (WFs) reliability analysis includes wind turbine generator (WTG) detailed models besides wind speed (WS) probabilistic variations considering wake effects. This paper is considered as an extension to the proposed multi-state duration sampling model to asses WTG reliability integrated with a comprehensive representation for WF. The paper investigates the impacts of two WTG frequency support operation algorithms on capacity factors and first hierarchical level indices. LOEE is evaluated using a novel method to emphasis the chronological coordination between load and WS attitudes. System and load points’ reliability indices are estimated at moderate penetration levels of wind energy using a simplified technique. Results insure the feasibility of the composite WTG reliability model and provide reasonable indicators for WFs integration influence

    OPTIMAL REQUIREMENT DETERMINATION FOR PRICING AVAILABILITY-BASED SUSTAINMENT CONTRACTS

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    Sustainment constitutes 70% or more of the total life-cycle cost of many safety-, mission- and infrastructure-critical systems. Prediction and control of the life-cycle cost is an essential part of all sustainment contracts. For many types of systems, availability is the most critical factor in determining the total life-cycle cost of the system. To address this, availability-based contracts have been introduced into the governmental and non-governmental acquisitions space (e.g., energy, defense, transportation, and healthcare).However, the development, implementation, and impact of availability requirements within contracts is not well understood. This dissertation develops a decision support model based on contract theory, formal modeling and stochastic optimization for availability-based contract design. By adoption and extension of the “availability payment” concept introduced for civil infrastructure Public-Private Partnerships (PPPs) and pricing for Performance-Based Logistics (PBL) contracts, this dissertation develops requirements that maximize the outcome of contracts for both parties. Under the civil infrastructure “availability payment” PPP, once the asset is available for use, the private sector begins receiving a periodical payment for the contracted number of years based on meeting performance requirements. This approach has been applied to highways, bridges, etc. The challenge is to determine the most effective requirements, metrics and payment model that protects the public interest, (i.e., does not overpay the private sector) but also minimizes that risk that the asset will become unsupported. This dissertation focuses on availability as the key required outcome for mission-critical systems and provides a methodology for finding the optimum requirements and optimum payment parameters, and introduces new metrics into availability-based contract structures. In a product-service oriented environment, formal modeling of contracts (for both the customer and the contractor) will be necessary for pricing, negotiations, and transparency. Conventional methods for simulating a system through its life cycle do not include the effect of the relationship between the contractor and customer. This dissertation integrates engineering models with the incentive structure using a game theoretic simulation, affine controller design and stochastic optimization. The model has been used to explore the optimum availability assessment window (i.e., the length of time over which availability must be assessed) for an availability-based contract
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