System separation mechanism in the neighbourhood of a relevant type-n UEP using the normal form of vector fields

Using the real nonlinear transformation in the normal form technique, the system trajectory in the neighbourhood of an equilibrium point can be observed in the decoupled modal space. This approach has been extended to study the mechanism of power system separation in the vicinity of a relevant type-n unstable equilibrium point (UEP) after a specific disturbance. Computer results from the 17-generator IEEE system show clearly that the effective unstable modes of a relevant type-n UEP and the corresponding modal characteristics play a significant role in the system separation