Static Switching Security in Multi-Period Transmission Switching

Transmission switching can improve the economic benefits of a power system through changing its topology during operations. However, the switching operation itself represents a step change in power systems, which is, to some extent, similar to a contingency that can bring disturbances into systems. This paper proposes a new model for multi-period, static-security-constrained transmission switching. Because the power flow on the network will be redistributed instantaneously after the switching operations, the new model involves using disjunctive programming, which considers two sets of power flow equations under possibly different topologies before/after switching. Each switchable transmission element is modeled into four actions or disjunctions. An action transition diagram coupling of four actions in different hours is used to represent feasible paths of instantaneous changes in the element status. Disjunctive formulations are transformed into mixed-integer programming problems. We compare the difference of the previous transmission switching model and the proposed one by using several numerical tests and verify the effectiveness of our solution methodology in the six-bus and RTS-96 systems.