Tractable Transmission Topology Control Using Sensitivity Analysis

The standard economic generation dispatch (ED) minimizes generation costs subject to transmission constraints, where the status of each line, i.e., open or closed, is fixed. Recent research shows that, by optimally dispatching the network topology along with generation resources, significant congestion costs may be avoided. Optimal topology control, i.e., appropriate changes of transmission-line status, for real-sized power networks requires the solution of a computationally intractable mixed-integer linear program; however, it appears that much of the cost savings may be attained by changing the status of just a few lines. This paper proposes tractable transmission topology control policies, which employ sensitivity information readily available from the ED to select candidate lines to change status while maintaining system connectivity. Implementation on the IEEE 118-bus test system found that our best performing policy captured an average of 96% of the potential cost savings. Moreover, the limited computational effort required suggests that these policies could be employed in real-system operations.