title: Assessing Short-Term Voltage Stability of Electric Power Systems by a Hierarchical Intelligent System.
abstract: In the smart grid paradigm, growing integration of large-scale intermittent renewable energies has introduced significant uncertainties to the operations of an electric power system. This makes real-time dynamic security assessment (DSA) a necessity to enable enhanced situational-awareness against the risk of blackouts. Conventional DSA methods are mainly based on the time-domain simulation, which are insufficiently fast and knowledge-poor. In recent years, the intelligent system (IS) strategy has been identified as a promising approach to facilitate real-time DSA. While previous works mainly concentrate on the rotor angle stability, this paper focuses on another yet increasingly important dynamic insecurity phenomenon-the short-term voltage instability, which involves fast and complex load dynamics. The problem is modeled as a classification subproblem for transient voltage collapse and a prediction subproblem for unacceptable dynamic voltage deviation. A hierarchical IS is developed to address the two subproblems sequentially. The IS is based on ensemble learning of random-weights neural networks and is implemented in an offline training, a real-time application, and an online updating pattern. The simulation results on the New England 39-bus system verify its superiority in both learning speed and accuracy over some state-of-the-art learning algorithms.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Junhua
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhao Yang
authors.initials: ZY
authors.lastname: Dong
authors.forename: Dianhui
authors.initials: D
authors.lastname: Wang
authors.forename: Hongming
authors.initials: H
authors.lastname: Yang
authors.forename: Kit Po
authors.initials: KP
authors.lastname: Wong