Resilience of Electricity Distribution Networks - Part II: Leveraging Microgrids

Advances in microgrids powered by Distributed Energy Resources (DERs) make them an attractive response capability for improving the resilience of electricity distribution networks (DNs). This paper presents an approach to evaluate the value of implementing a timely response using microgrid operations and DER dispatch in the aftermath of a disruption event, involving strategic compromise of multiple DN components. Firstly, we extend the resiliency assessment framework in [1] and develop a sequential (bilevel) model of attacker-operator interactions on a radial DN with one or more microgrids. Particularly, the operator response includes microgrid operations under various islanding configurations (regimes), and single- or multi-master operation of DERs in providing grid-forming services as well as frequency and voltage regulation. Secondly, we introduce a restoration problem in which the operator gradually reconnects the disrupted components over multiple periods to restore the nominal performance of the DN. The first problem, formulated as a bilevel mixed-integer problem, is solved using a Benders decomposition method. The second problem, formulated as a multi-period mixed-integer problem, can be solved using a greedy algorithm. Our results illustrate the benefit of using microgrids in reducing the operator's losses, both immediately after the disruption event and during the restoration process.