Stability Issues of Smart Grid Transmission Line Switching

This paper investigates the stability issues that might arise when incorporating transmission line switching into smart grid planning and operation. To demonstrate the feasibility of line switching, we use scenarios and dynamic simulations to demonstrate system security margin and online stability issues. Results show that proper line switching can resolve system emergency and boost system security margin, even though less transmission lines are used. Also it reveals that small signal instability can be triggered by line switching. It is necessary to apply sophisticated voltage controls and power system stabilizers (PSS) to avoid triggering rotor angle and voltage small signal instability for full benefits of line switching.