Assessment of Robustness of Power Systems from the Perspective of Complex Networks

In this paper, we study the robustness assessment of power systems. Since the power grid is an electrical network by nature, it can be fully and accurately described by circuit laws. Based on Kirchhoff´s laws and the properties of network elements, we propose a complex network model that generates power flow information given the electricity consumption and generation information. It has been widely known that large scale blackouts are results of a series of cascading failures triggered by the malfunctioning of specific critical components. Power systems can be more robust if there are fewer such critical components or the network configuration is suitably designed. The percentage of unserved nodes (PUN) caused by a failed component and the percentage of non-critical links (PNL) that will not cause severe damage are used to provide quantitative indication of a power system´s robustness. We study the IEEE 118 Bus, Northern European Grid and other practical power systems. Simulation results show that small-world connection of the grid can significantly degrade a power system´s robustness.