Microgrid Maintenance Strategies for Optimal Reliability and Cost

Abstract

A physics-based microgrid model has been developed in Simulink with various sources and loads driven by stochastic inputs. Central controls are used to drive down costs while maintaining a reasonable level of reliability. The microgrid is treated as a repairable system where power sources are repaired after failure. We consider the effectiveness of the repair. Repairable systems theory allows us to model repair assumptions such as “good as new” or “as good as old” for example using a renewal process approach. At some point during the operation of the microgrid, some of its subsystems reach their useful life and need to be replaced. This study looks at the trade-off between microgrid reliability and the cost of repair, replacement and operation. The proposed approach can be used to define optimal maintenance strategies. Using repair theory, different repair/maintenance approaches are compared and shown to provide different operational costs and system reliability. An approach is provided to determine an optimal maintenance/repair strategy.