Toward Look-ahead Line Switching for Enhancing Static Voltage Stability

In this paper, a look-ahead contingency-constrained line switching problem (CCLS) is presented to enhance static voltage stability of look-ahead (say 30 minutes) base case, as well as a credible set of contingency cases. The aim of the proposed problem is to find an optimal network topology by switching out a transmission line which can maximize load margin of lookahead base case while ensuring load margins of a credible set of contingency cases to an acceptable level. And the `new' network topology after switching out the solution line cannot lead to new critical contingencies and voltage and thermal violation for post-switching look-ahead base case. In order to solve the proposed problem in online environment, we develop a sub-problem-based methodology to identify a `best' switching line solution and enable tractable computation. The numerical results on IEEE 118-bus power system verify the effectiveness of the proposed methodology.