Unified two-stage reconfiguration method for resilience enhancement of distribution systems

Fast load restoration based on network reconfiguration is a key step to enhance the resilience of distribution systems (DSs). For DSs equipped with remote-controlled switches (RCSs), the reconfiguration can be completed promptly. However, when the branch is equipped with manual switches only, it cannot be operated immediately, and its post-event state is determined by its pre-event state. Considering these facts, this study proposes a unified two-stage reconfiguration method for the resilience enhancement of DSs. In the pre-event stage, the allocation of RCSs and the reconfiguration of the network are determined to prepare the system for a set of possible fault scenarios caused by upcoming extreme weather. In the post-event stage, network reconfiguration based on the placed RCSs is performed for fast load restoration to minimise the loss of load expectation (LOLE). A new mathematical expression is proposed to ensure the radial operation of DSs with islanded DSs and islanded microgrids. To improve the computational efficiency, the scenario decomposition algorithm is employed to decompose the proposed model into several subproblems, which can be solved in parallel. The results show that the proposed method can significantly reduce the LOLE caused by extreme weather events, thus enhancing the resilience of DSs.