Transient Stability Improvement by Generator Tripping and Real-Time Instability Prediction Based on Local Measurements

Special protection systems based on generator tripping are implemented to protect power systems against the loss of synchronism following extreme contingency events. Such a countermeasure is particularly effective when the circuit breakers of the tripped generators are opened soon after the fault is cleared. This paper presents the new method that enables quick real-time predictions of transient instability and the number of generators that must be tripped. The proposed method uses only local measurements and is based on the quick prediction of the magnitude of the power-angle characteristic. The proposed method has been validated by simulation tests performed for a large-scale real power system and detailed models of power system elements.