Modeling the Effects of Maintenance on the degradation of a Water-feeding Turbo-pump of a Nuclear Power Plant

International audienceThis work addresses the modelling of the effects of maintenance on the degradation of an electric power plant component. This is done within a modelling framework previously proposed by the authors, of which the distinguishing feature is the characterization of the component living conditions by influencing factors (IFs), i.e. conditioning aspects of the component life that influence its degradation. The original fuzzy logic-based modelling framework includes maintenance as an IF; this requires one to jointly model its effects on the component degradation together with those of the other influencing factors. This may not come natural to the experts who are requested to provide the if-then linguistic rules at the basis of the fuzzy model linking the IFs with the component degradation state. An alternative modelling approach is proposed in this work, which does not consider maintenance as an IF that directly impacts on the degradation but as an external action that affects the state of the other IFs. By way of an example regarding the propagation of a crack in a water-feeding turbo-pump of a nuclear power plant, the approach is shown to properly model the maintenance actions based on information that can be more easily elicited from experts

A new modeling framework of component degradation

International audienceModeling the degradation process of a component is a fundamental issue for maintenance poli-cy definition. In this work, a degradation model based on the concept of component "effective age‟ is pro-posed. The effective age of a component is treated like a physical variable, indicative of its degradation state, and allows to describe the fact that age may evolve faster or slower than chronological time in adverse or fa-vorable working conditions, respectively. Under this concept, the objective of degradation modeling becomes the identification of the relations between the environmental and operating conditions of the component and its effective age. In particular, the proposed degradation modeling paradigm is thought to be applied to the situation, very common in practice, in which the only available information to build the model is that elicited from experts. The proposed modeling framework is applied to a real case study of a medium voltage test net-work

A modelling framework to assess maintenance policy performance in electrical production plants’

A framework to qualitatively assess the performance of maintenance policies in electrical production plants is presented. A Monte Carlo simulation scheme is combined with fuzzy logic for modelling the component degradation. The novelty of the work consists in the modelling of the influence of the actual living conditions on the degradation of the specific component under analysis; this is done by using linguistic fuzzy rules which formalize the expert knowledge on the degradation process. An example of application regarding a water-feeding turbo pump is presented to illustrate the potential of the proposed approach

An hybrid Monte Carlo and Fuzzy Logic method for maintenance modelling

International audienceA framework previously proposed by the authors to qualitatively assess the performance of maintenance policies in electrical production plants is summarized in this work; the distinguishing feature of this framework is the characterization of the living conditions of a component by means of Influencing Factors (IFs), i.e., conditioning aspects of the component life that determine the evolution of the degradation mechanisms affecting the component. Modelling of this evolution is addressed via an hybrid Monte Carlo simulation and fuzzy logic scheme which provides the basis for assessing the performance of a maintenance policy