Fault recovery method of DC distribution network considering EV charging and discharging and SOP network reconfiguration
Yongqiang Kang, Gang Lü, Meng Chen, Xinglong Li, Shuaibing Li
Abstract
In the post-disaster fault recovery scenario, the decentralized scaled electric vehicles (EV) have considerable discharging potential, coupled with photovoltaic energy storage power supply equipment, which can effectively underpin the re-establishment of power supply for crucial loads within the DC distribution network and cut down power outage losses. This paper puts forward a fault recovery approach for the DC distribution network, which is founded on the charging and discharging of EV as well as the network reconfiguration of soft open points (SOP). To begin with, by leveraging the vehicle-to-grid interaction characteristics of EV, the power model for EV charging and discharging and the discharging response model are formulated. Further considering the regulation of SOP on power flow distribution and the connectivity characteristics of the main network, an SOP model suitable for DC distribution network is established. Next, the island partition model is developed, aiming to optimize the priority restoration of important loads. Based on this, a two - tier fault recovery model is built, taking into account the distribution network system loss, the total voltage deviation, and the income of EV users. The upper-layer model is resolved using the multi-objective particle swarm optimization algorithm to ascertain the optimal discharging power for each discharging station. The lower-layer model is solved by the simulated annealing algorithm to decide the optimal access location for the SOP network reconstruction, so as to obtain the optimal fault recovery scheme. Finally, by taking the modified IEEE 33-node DC distribution network as a case study, the proposed fault recovery method is analyzed and validated. The results show that in the fault recovery process of the DC distribution network with a scaled presence of EV, this approach is capable of not merely satisfying the power-supply restoration of crucial loads, but also guaranteeing the optimal performance in terms of system network loss, total voltage deviation, and the enhancement of EV users' income.