Study on the Dynamic Identification Method for Key Branch of AC Weak Section and Transient Stability Control Scheme

AC section of oscillation center placed, which is suffered by the large disturbance fault, is the weak link at which the interconnected AC system would be lost synchronization stability and slatted. The key branch is the first branch that lead weak section “tearing”. It is of great significance to identify key branch and to take targeted control measures to improve the transmission capability and immunity of interconnected power grid. Aiming at AC/DC hybrid transmission system, based on the disturbed trajectory difference analysis during the process that stabilization levels continue to deteriorate, the dynamic identification method for the key branch is put forward, and successive instability mechanism of the multi-branch system is revealed. The control measures and the active control sensitivity evaluation indexes of the key branch are proposed. The control strategy for improving stability is proposed based on the sensitivity indictor. The simulation results of actual power network show that the dynamic identification method and the stability control strategy are effective.