Group-Based Line Switching for Enhancing Contingency-Constrained Static Voltage Stability

A look-ahead contingency-constrained line switching problem is presented to enhance the static voltage stability of a look-ahead (say 30 minutes) base case, respecting a set of credible contingencies. This problem seeks to identify the `best' network topology by switching out transmission lines to maximize the load margin of a look-ahead base case while ensuring the load margins of a set of credible contingencies are acceptable. Moreover, the voltage and thermal limitations are respected in the post-switching look-ahead base case. To solve the problem in an online environment, a group-based method is developed to reduce the complexity of the contingency constraints and enable tractable computation. Extensive numerical results on the IEEE 118-bus and the 1648-bus power systems examine the effectiveness of the proposed methodology.