Abstract:
With the expansion of power grid, the consequences caused by blackouts are more serious. Black start is an effective measure to restart the paralyzed power grid, and the grid reconfiguration is an important part of the black start process. In order to improve the black-start efficiency of power system after blackout and make full use of the advantages of distributed system as black start power in the process of grid restoration, a grid reconfiguration strategy of black start based on niches collaborative interconnection is proposed in this paper. Firstly, with the help of Kruskal algorithm in graph theory, the restoration grid is abstracted based on the node and branch weight. The main goal is the shortest recovery time and the black-start grid reconfiguration optimized model is constructed. Secondly, an improved niche genetic algorithm is proposed to solve the model under the action of double mechanisms of squeezing and pre-selection. On this basis, a recovery strategy of serial-parallel cooperation is introduced to achieve niche collaborative interconnection. The optimal adjustment of the grid reconfiguration process is achieved through the above solving process. Finally, the IEEE 39 simulation results are evaluated with the indices of recovery time, voltage offset and active power loss by comparing with the pre-improvement method. It is concluded that the proposed method can effectively improve the reconfiguration speed and ensure the stability of collaborative interconnection. Meanwhile, the validity and feasibility of the proposed model are verified by the local power grid in Zhenjiang, Jiangsu Province.