Critical infrastructure identification in microgrid system via reliability evaluation

The microgrid system (MS) is composed of several infrastructures, including energy sources, converters, and feeders. Due to the increasing complexity and climate change, assessing grid reliability and identifying critical infrastructure have become critical issues for the operator. Accordingly, a reliability-based framework for identifying the critical infrastructure within the MS is proposed in this study. Grid reliability serves as a performance metric to measure the supply capability of the MS, which is defined as the possibility that the demand of the user can be met. Considering that infrastructures in the MS may operate at multiple state levels due to failures or maintenance, the power rating of these infrastructures should be viewed as multistate. Network analysis is employed in this study, a practical approach that considers the multistate power rating in the MS by constructing a stochastic microgrid network (SMN). Based on calculated grid reliability, the infrastructure importance analysis is introduced to systematically assess the impact of a complete failure of each infrastructure on grid reliability. An illustrative example is provided to demonstrate the feasibility of the proposed framework, assisting the operator in evaluating SMN grid reliability and identifying the critical infrastructure that significantly impacts SMN performance.