Application of Emergency-Single Machine Equivalent method for cascading outages

Controlled islanding has been widely proposed as a last resort action to prevent blackouts from spreading when usual methods fail in the three-defence-line scheme. In view of global blackouts, these happened largely due to cascading outages, which could lead to transient instability and system collapse. Therefore, transient stability assessment is an important issue for islanding. In order to tackle this issue, Emergency-Single Machine Equivalent (E-SIME) method uses real-time information provided by phasor measurement units to predict transient status of power system and takes corresponding emergency control before imminent transient instability. This paper demonstrates the application of E-SIME in cascading line trips to give decision support for implementation of controlled islanding scheme in terms of transient stability.