Improving the resilience of active distribution networks by optimal charging/discharging management of electric vehicles in parking lots

In the event of a severe incident with a high impact and low probability of occurrence, distribution networks may be separated from upstream networks and several feeders may be disconnected simultaneously within the distribution networks. In such circumstances, to maximize the resilience of the distribution networks and to prevent long-term global outages, they are reconfigured and islanded to allow restoring the loads as much as possible. On the other hand, because of the increasing penetration of electric vehicles in today's advanced societies for environmental reasons and fossil fuel prices, charging and discharging management of plug-in electric vehicles (PEVs) into parking lots can have a significant impact on improving the resilience of distribution networks. Technically, electric vehicles can be connected to the electrical grid in two modes of charging or grid-to-vehicle (G2V) mode as an electrical load and discharging or vehicle-to-grid (V2G) mode as energy storage units. Therefore, this paper proposes a mixed integer linear stochastic programming model to improve the resilience of distribution networks equipped with distributed generation (DG) resources. The proposed model optimizes the distribution network reconfiguration with the aim of maximizing load restoration criteria by using optimal charging and discharging planning of PEVs in parking lots. In the proposed model, the master and slave DGs in each island and the charging and discharge planning of PEVs are optimally determined considering the movement of PEVs between parking lots and the formation and boundaries of the islands. To present a realistic model, the uncertainty of the generation capacity of renewable wind resources is also taken into account. The proposed model has been implemented and validated by applying several concurrent faults on a 118-bus distribution network in GAMS software. The results show the positive impact of PEVs parking lots on improving the resilience and increasing the load recovery of the distribution network.