Real-time transient instability detection based on perturbed voltage trajectories

With the application of phasor measurement unit, the response-based security and stability technology has become a hot topic. In this paper, an engineering transient instability detection method is presented on the basis of the perturbed voltage trajectories. Proceeding from the vulnerable buses of power system, a time-domain perturbed voltage integral is utilized to represent the desynchronization of incoherent generator groups and to assess the real-time transient stability of the system. Different from methods that based on angle trajectories, the proposed method can be applied to incomplete wide-area measurements and adapt to multiswing stability analysis without computing the center of inertia. The proposed approach is robust and has good practical feasibility. It improves the existing work in terms of monitoring scheme and threshold value setting. The proposed method is tested on the IEEE 39-bus system and the China Southern Power Grid. Simulation results show that the proposed method is reliable and can be applied to modern interconnected power systems.