On Grid Partitioning in AC Optimal Power Flow

The AC optimal power flow problem is known to be highly non-convex and scale very poorly with respect to the number of lines and buses. One possible solution is to subdivide and parallelize the problem through distributed optimization. However, the question of how to optimally partition a power grid for use in distributed optimization remains open in the literature. To this end, we compare the graph partitioners KaFFPa and METIS as well as two spectral clustering methods to the standard IEEE 9, 14, 30, 39, 57, 118, 300 bus models. The distributed algorithm ALADIN is used to solve the partitioned OPF problems. For larger grids, KaFFPa yields the best results on average.