Research Of Damping Coupling Relation Between LFO And SSO Of Power System

It is usual that LFO (low frequency oscillation) happens in modern power system. Although PSS(Power System Stabilizer) can suppress LFO very well, it may have ill effect on SSO(Subsynchronous Oscillation). With the consideration of possible coupling relation between LFO and SSO, models of LFO, simple model with decomposed shaft and unify model of LFO and SSO are analyzed using small disturbance approach. The conclusion of damping conservation is deduced. In addition, the influence of PSS and TCSC is analyzed to system damping. Calculation and analysis are performed to real examples using eigenvalue approach by altering system conditions and controller characters. The conclusion provides academic bases to restrain LFO and SSO and is significant to the security and stability of power system.