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.