Tools for improving resilience of electric distribution systems with networked microgrids

In the electrical grid, the distribution system is the most vulnerable to severe weather events. Well-placed and coordinated upgrades, such as the combination of microgrids, system hardening and additional line redundancy, can greatly reduce the number of electrical outages during extreme events. Indeed, it has been suggested that resilience is one of the primary benefits of networked microgrids. We formulate a resilient distribution grid design problem as a two-stage stochastic program and make use of decomposition-based heuristic algorithms to scale to problems of practical size. We demonstrate the feasibility of a resilient distribution design tool on a model of an actual distribution network. We vary the study parameters, i.e., the capital cost of microgrid generation relative to system hardening and target system resilience metrics, and find regions in this parametric space corresponding to different distribution system architectures, such as individual microgrids, hardened networks, and a transition region that suggests the benefits of microgrids networked via hardened circuit segments.