Research On Static Structural Vulnerability Of Power System Based On Generalized Tellegen’s Theorem

The safe and reliable operation of power system relates to the national security andeconomic prosperity, along with the expansion of the electric power grid’s scale, the powersystem is becoming more and more complicated, and the structural vulnerability whichreflects the essential characteristics of the power grid becomes more prominent. Effectivevulnerability assessment index and method is the key to study the electric power grid’svulnerability. To assess the structural vulnerability of power system has certain theoreticalsignificance and practical value.The study of this thesis is based on the concept of the structural vulnerability of powersystem. A in-depth analysis of the characteristics and the factors which affect the structuralvulnerability of power system, and a detailed description of the principles, the evaluatingmetrics and the evaluation methods which are used to assess the structural vulnerability ofpower system. Measures for structural vulnerability analysis are imperfect. The topologicalstructure model of power system is simple and abstract, and the proposed topological metricsfail to capture the electrical properties of power grid. The existing study on the structuralvulnerability of power system is based on a hypothesis that some kind of fault occurs in thepower grid, but there is few study considering the factor that load variation can be passed onto the change of structure of power grid quietly. The study of this thesis is based ongeneralized Tellegen’s theorem, considering the influence of load variation to the structuralvulnerability.This thesis proposes a method considering the influence of load variation to thestructural vulnerability. When the phenomenon of Virtual-short, Virtual-cut off happens inpower system, we establish the topological structure model after being weighted of powersystem, applying the law of power redistribution. This thesis proposes the concept of staticstructural vulnerability, using the method of fuzzy clustering to put forward a metric forassessing static structural vulnerability of power system.The proposed method is tested on the IEEE14-bus and IEEE30-bus test system on theplatform of MATLAB. The simulation results verify the effectiveness and practicability of themetric. And the results show that considering the influence of load variation to the structuralvulnerability is a effective method.