Abstract: A failure cascading model for power systemes is proposed,in which energy dissipation and capability expansion are considered.Simulations are performed on both regular grids and scale-free networks.Self-organized critical phenomenon is observed in both cases.It means that energy dissipation and capability expansion are important factors in self-organized critical status.In addition,it shows that the maximum size of cascading failures in scale-free networks is much larger than that in regular networks.

Key words: self-organized criticality, cascading failure, power system