Synchrophasor-Based Monitoring of Critical Generator Buses for Transient Stability

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 the current practice of monitoring the power transfer limit on a given interface, this paper proposes a real-time synchrophasor method to monitor the stability margin using generator phase angle differences and alert operators of the potential risk to the system at the steady state operation. This is accomplished by developing an algorithm to directly correlate the phase angle separation of critical generator bus pairs to power transfer on major interfaces. These critical generator bus pairs are selected systematically through transient stability simulation. The Eastern North American power system is used as a platform to illustrate the utility of the proposed method.