  Power flow calculation in EMS is required to accommodate a large and complex
power system. To achieve a faster than real-time calculation, a graph based
power flow calculation is proposed in this paper. Graph database and graph
computing advantages in power system calculations are presented. A linear
solver for power flow application is formulated and decomposed in nodal
parallelism and hierarchical parallelism to fully utilize graph parallel
computing capability. Comparison of the algorithm with traditional sequential
programs shows significant benefits on computation efficiency. Case studies on
practical large-scale systems provide supporting evidence that the new
algorithm is promising for online computing for EMS.

Signal Processing;Distributed, Parallel, and Cluster Computing;Systems and Control