Analyzing dynamic performance of power systems over parameter space using normal forms of vector fields - Part II: Comparison of the system structure

This is part II of a two-part paper dealing with dynamic performance of pow er systems over the parameter space. The companion paper (part I) proposes an approach to identify unfavorable operating regions by searching for reso nance and near-resonance, The results show that near-resonance among critic al inertial modes and control modes may contribute to the unsatisfactory be havior of the system. In this paper, the effect of strong nonlinear modal i nteractions on machine states is quantified. A new index is derived to meas ure the relative severity of the near-resonance, The linear and nonlinear c haracteristics of the system are separated and correlated to the transient stability of the system.