Graph space
What it does
Graph Space removes the diagram layout and the geography. It shows the network as a graph: nodes and edges. This is what the network is, electrically. A force-directed layout sets the positions. The structure comes from the connections, not from where a person drew a symbol.
This view makes problems visible that are difficult to see on a diagram:
- Topological islands. An island is a group of connected elements with no path to the rest of the network. Each island moves apart from the others on the screen. Phasor puts a label on each island. An island with no source is the most frequent reason why a power flow does not converge.
- Radial structure. A correct radial feeder becomes a tree shape. If a feeder does not become a tree, the feeder contains a loop.
- Parallel paths that you did not intend. A closed switch that must be open makes a cycle in the graph. You see the cycle directly. You do not trace crossing lines by eye.
- Depth from the source. The number of switching stages between a load and its supply.
How to use it
- Open Graph Space next to the diagram. The two views share the selection. When you click a node, Phasor highlights the same element on the SLD.
- Check the number of islands. A healthy network with one supply has one island. If there are more islands, the panel names each island and lists its elements.
- Trace a path. Select a bus. Trace the path back to its source. You see each switch and each transformer on the path.
- Look for cycles. Phasor marks each loop. For each loop, decide: is this loop intended (for example, a ring main), or is it a switch that is closed in the model by mistake?
- Make corrections in the SLD editor. Graph Space is a read-only view of the topology. You change the model on the SLD. The graph updates immediately.
Inputs and outputs
Inputs
| Input | Notes |
|---|---|
| Network topology | The buses and branches from the model. |
| Switch states | An open switch removes an edge. This is what makes islands. |
| Source designation | The nodes that are supply points. Phasor uses them for the island and depth analysis. |
Outputs
| Output | Notes |
|---|---|
| Islands | The count, the members of each island, and whether each island contains a source. |
| Cycles | Each loop in the connected graph. |
| Path traces | The sequence of elements from a node to its source. |
| Depth | The number of switching stages between each load and its supply. |
| Degree | The number of branches that meet at each node. |
Notes
A solver cannot solve an island that has no source. A power flow needs one slack bus in each island. Graph Space shows you which island has no source before you run the solver.
A wrong switch state is the usual cause of an unexpected island. Two examples: a normally-open point that must be closed for your scenario, or a switch that must be open but is closed. One switch state can change the full topology.
Use Graph Space before each important study. The check takes seconds. It finds topology errors before they become wrong results.
No coordinates, by design
In this view, the distance between two nodes on the screen has no meaning. The position of a node has no geographic or schematic meaning. Graph Space is an instrument for topology, not a map. When distance is important, use the GIS view.