Automatic Layout of One-Line Diagrams for Large Transmission Systems Based on Graph Partitioning

One-line diagrams are widely used in power system applications, but their automatic layout remains a challenge. Currently, most approaches are dedicated to solving the layout of small-scale power transmission systems to produce aesthetically pleasing one-line diagrams. To extend them to large-scale systems, this paper proposes an integrated framework for the automatic layout of one-line diagrams based on graph partitioning. Graph partitioning allows a large graph to be divided into multiple subgraphs, and the layout for each subgraph is optimized using mixed-integer linear programming (MILP). These optimized subgraphs are then reassembled into a large graph using the subgraph assembly algorithm and the tie-line routing strategy. The case studies demonstrate that the proposed framework can efficiently generate one-line diagrams that satisfy aesthetic criteria. The output layout can preserve the relative position of nodes as in the original layout, which significantly improves its readability. Moreover, the time consumption of the proposed framework is acceptable for practical use.