Abstract:Based on the IEEE118 system, a weighted power grid with electrical characteristics and a power grid with only topological structure are constructed respectively. Secondly, a non-linear load capacity model is proposed, which is used to simulate the cascading failure through random attacks. The results show that the threshold of the capacity parameter of the weighted power grid is smaller than that of the unweighted power grid, and more resistant to cascading failure. Finally, through deliberate attacks, it is found that the robustness of weighted power grid is more stronger to cascading faults against power attacks than unweighted power grids against degree attacks. But the betweenness attacks of weighted power grid are similar to those of unweighted power grids, and it is less robust to cascading failure; The reason is that the high- betweenness nodes are transformer nodes in the IEEE118 system, which is very important for the transmission of the power grid, and its protection needs to be strengthened in the actual power grid.