ABSTRACT
Power grid vulnerability is a key issue with large blackouts, causing power disruption for millions
of people. The complexity of power grid, together with excessive number of components, makes it
difficult to be modeled. Currently, researchers use complex networks to model and study the performance
of power grids. In fact, power grids can be modeled into a complex network by making
use of ring network topology, with substations and transmission lines denoted as nodes and edges,
respectively. In this paper, three protection schemes are proposed and their effectiveness in protecting
the power network under high and low-load attacks is studied. The proposed schemes,
namely, Cascaded Load Cut-off (CLC), Cascaded Load Overflow (CLO) and Adaptive-Cascaded Load
Overflow (A-CLO), improve the robustness of the power grids, i.e., decrease the value of critical tolerance.
Simulation results show that CLC and CLO protection schemes are more effective in improving
the robustness of networks than the A-CLO protection scheme. However, the CLC protection
scheme is effective only at the expense that certain percentage of the network will have no
power supply. Thus, results show that the CLO protection scheme dominates the other protection
schemes, CLC and A-CLO, in terms of the robustness of the network, improved with the precise
amount of load cut-off determined.