Security Region Analysis of Sub/Super-Synchronous Oscillations in Wind Power Systems

The integration of wind power has caused severe sub/super-synchronous oscillations (SSOs) in today's power systems. To analyze the stability of SSO under different operating conditions, it is of great significance to construct its security region (SR). This paper first proposes the concept of SR for SSOs based on the impedance network model (INM). Then the frequency characteristics of the aggregated impedance is used to judge the oscillatory stability and the boundary of SR is built via seeking critical stable operating points. Finally, the proposed method is illustrated by constructing the SR of a practical wind power system that experienced actual SSOs. Its effectiveness is verified with electromagnetic simulations.