Multi-mode oscillation damping of power systems by a single UPFC

This paper investigates the feasibility of multi-mode oscillation damping by using a single UPFC (unified power flow controller). The UPFC can fulfil multiple control functions by implementing multiple controllers. Supplementary damping control can be superimposed on any normal control function to perform the task of damping control. Hence technically it is applicable for a single UPFC to damp multi-mode power system oscillations, as multiple damping controllers can be superimposed on the single UPFC. The controllability index is calculated to determine which channels of the UPFC can be superimposed with damping controllers efficiently. Then the parameters of damping controllers are optimized by using the artificial fish school algorithm. Finally simulation result shows that the damping controllers designed can effectively suppress the multi-mode oscillations.