Evaluating Resilience of Electricity Distribution Networks via A Modification of Generalized Benders Decomposition Method

Abstract

This paper presents a computational approach to evaluate resilience of electricity Distribution Networks (DNs) to cyber-physical failures. In our model, we consider an attacker who targets multiple DN components to maximize the loss of the DN operator. We consider two types of operator response: (i) Coordinated emergency response; (ii) Uncoordinated autonomous disconnects, which may lead to cascading failures. To evaluate resilience under response (i), we solve a Bilevel Mixed-Integer Second-Order Cone Program which is computationally challenging due to mixed-binary variables in the inner problem and non-convex constraints. Our approach is based on Generalized Benders Decomposition method, that achieves a reasonable tradeoff between computational time and solution accuracy. Our approach involves modifying the Benders cut based on structural insights on power flow over radial DNs. We evaluate DN resilience under response (ii) by sequentially computing autonomous component disconnects due to operating bound violations caused by the initial attack and the potential cascading failures. Our approach helps estimate the gain in resilience under response(i), relative to (ii).