Bi-level service restoration strategy for active distribution system considering different types of energy supply sources

With increasing power consumption and the number of active units, such as distributed generators (DGs), energy storage systems (ESSs), and transportable ESSs (TESSs), in the distribution system, the requirements for the operability of the power system restoration service increase as well. In this study, the authors propose a new bi-level optimisation strategy for service restoration (SR) to minimise the final cost of the restoration process and to re-energise the maximum number of customers. The proposed method considers different power resupply methodologies, such as topology reconfiguration-based restoration, islanding operation of DG, and the application of TESS for SR, along with their optimal combination, to minimise the financial costs. The primary level comprises a reconfiguration approach and a genetic algorithm to optimise the islanding partition of an active distribution system; the second level consists of the fuzzy logic procedure to set up the combination of energy resources. In addition, this study considers the objective problem formulation as a combination of different subtasks, which represent the financial costs of various components during the restoration process. Case studies are conducted on a modified IEEE 39-bus distribution network, where the validity and effectiveness of the proposed strategy are demonstrated.