Day-Ahead Voltage Stability-Constrained Network Topology Optimization with Limited Number of Actions

A day-ahead voltage stability-constrained network topology optimization (DVNTO) problem is proposed to ensure the enough hourly voltage stability margin of power systems under a minimal number of switching and splitting operations, as well as ensure the engineering operation requirements of power systems. The AC continuation power flow and the uncertainties from renewables and loads are incorporated in the problem formulation. The network topology is optimized by both line switching and bus-bar splitting in this paper. The proposed DVNTO problem is a stochastic, large-scale, nonlinear integer programming problem, which is solved by a proposed three-stage solution method. A dynamic-based partition strategy is presented to partition the hours into several periods according to the hourly voltage magnitude drop between the power flow point and the bifurcation point, rather than the net load, in order to obtain the minimal amount of operations necessary to change the network topology for the upcoming 24-hour horizon. To address the challenges posed by the uncertain renewables and loads, a novel problem-specified scenarios construction process is proposed to generate all the possible scenarios and reduce the scenarios. Finally, the effectiveness of the proposed three-stage method, the dynamic-based partition method, and the robustness of the proposed method under heavy loading condition are evaluated on IEEE 118-bus and 3120-bus power systems.