Nested BBDF Partitioning Algorithm in Power System Parallel Computation

Network partitioning giving rise to the bordered block diagonal form (BBDF) admittance matrix is an effective approach in the field of power system parallel computation. A graph partitioning algorithm based on geographic information of power system was presented for the purpose of transforming the coefficient matrix of equations into nested BBDF (NBBDF),via edge cut set in a hierarchical way. Without destroying BBDF graphs' good performance in each layer,distributed storage of power grid data is adopted in this algorithm,which has little time overheads. In order to decrease fill-ins in the computation,it is necessary to renumber those nested borders produced by this algorithm through sparse technique. The proposed algorithm is quite competent for large scale power system parallel computation for the reason of less communications load and possible superlinearity phenomena in the case of large scale power system,demonstrated by those experimental results from parallel power flow calculation after a NBBDF partitioning which had been applied to the grid.