A mathematical framework for reliability-centered maintenance in microgrids

In this paper, the central principles of reliability-centered maintenance (RCM) and corresponding mathematical concepts for its implementation in microgrids are discussed. A systematic framework is suggested that exploits the fundamentals of multiattribute decision making to (i) evaluate the important features and failure attributes and (ii) effectively identify the microgrid critical components with their failure rates dynamically assessed at various time intervals. Lagrange multipliers of a budget-constrained optimization formulation are suggested to be used to determine the desired values of system reliability indicators. The failure rates of critical components are efficiently determined over time through an exponential model that is empirically obtained via extracted condition scores of critical failure causes at multiple inspection times. A time-varying benefit-to-cost ratio mechanism is designed via which the useful lifetime of critical components and the system economic benefits increase through timely maintenance in microgrids where an improved reliability performance can be realized. Finally, the proposed model is implemented in a real-world scenario on a microgrid that is a part of the Tehran power distribution network. Extensive numerical results demonstrate the applicability and effectiveness of the suggested RCM model in microgrids.