Transmission Network Expansion Planning Considering Disjoint Control

Splitting is an important measure to deal with power grid out-of-step oscillation. The system out-of-step cross-section is mainly distributed on the line called weak connection. Reducing the number of weak connection lines can optimize the system partition, rationally configure the splitting device, reduce the search time and solution set of the splitting cross-section, and enhance the effectiveness of the splitting control. Based on slow coherence theory, an improved method for identifying and screening weak connection lines is proposed. The ratio of the number of weak connection lines to the number of all lines is defined as the weak connection coefficient. A bi-level programming model of transmission network considering the splitting control is established with the minimum weak connection coefficient as the optimization objective. A hybrid algorithm based on Boruvka algorithm and particle swarm optimization with adaptive mutation and inertia weight is used to solve the above two-level model in an example of an 18-node IEEE Graver system and a practical power grid in East China. The fault simulation results in PSD- BPA show that the weak connection screening method and transmission network planning model are effective. © 2020, Power System Technology Press. All right reserved.