Monitoring power system transient stability using synchrophasor data

Many interconnected power systems are constructed to meet the ever increasing electric power transfer demand. A disturbance anywhere in such an interconnected system will directly influence the power transfer capability of major transfer interfaces, as well as the transient stability of the system. Instead of monitoring the power transfer limit on a given interface, we propose a real-time synchrophasor measurement-based method to monitor the dynamic stability margin of the power system. This is accomplished by directly correlating the phase angle separation and voltage sag of critical buses to power transfer increase on the interface. The Eastern North American power system is used as a platform to illustrate the utility of the proposed method.