Parallel power system restoration planning at distribution level considering uncertainty of renewable generation

The growing share of renewable energy sources (RES) in the grid introduces many challenges for the grid restoration process due to its volatile and intermittent nature. Thus, network operators tended to exclude RES from their restoration planning, leading to unutilized generation potential. This work proposes a two-step restoration algorithm with a focus on inclusion of RES to facilitate the restoration process. The first step involves the formation of electrically isolated islands each with at least one black-start (BS) unit to conduct parallel restoration and speed up overall grid recovery. The predefinition of suitable sections allows switching actions to enable the desired sections during the short time after blackout, which the battery capacities in the substations allow. The second step involves parallel restoration of the defined sub-systems based on optimal restoration paths identified using the modified k-shortest path algorithm to ensure redundancy and minimal restoration times. Lastly, the re-synchronization of sub-systems prepares the network for seamless reconnection with the upstream grid. The proposed approach is implemented and tested on IEEE 34-bus distribution system.