Network Simplification
Before the network is translated to OpenDSS, it is simplified to reduce the number of buses and lines the solver has to handle. This speeds up solves and removes equipment with no electrical effect. Simplification runs once per feeder and is on by default. Set simplifyNetwork to false to skip it entirely. The options are set in the Work Package Configuration Options.
Simplification Steps
The steps always run in this order, and each sees the network as left by the ones before it. Switches are always kept.
| Step | What it does | Runs when |
|---|---|---|
| Regulator sites | Replaces each voltage regulator site with a single regulator | Always |
| Out of service equipment | Removes equipment that is not in service | Always |
| Negligible impedance | Collapses connected equipment with impedance below negligibleImpedanceMinHvThreshold or negligibleImpedanceMinLvThreshold into connectivity nodes | collapseNegligibleImpedances is true |
| SWER networks | Collapses SWER networks back to their isolation transformers | collapseSwer is true |
| LV networks | Collapses LV networks below distribution transformers into a single bus | collapseLvNetworks is true |
| Impedance normalising | Replaces similar impedances along a run of conductors with one weighted average | simplifyPLSIThreshold is set |
| Common impedance | Combines runs of conductors with the same impedance and rating into one longer conductor | combineCommonImpedances is true |
Span Level Ratings and Improved Network Collapsing
This feature is only available to certain customers. If you are interested in using this feature, please contact Zepben for more information.
Span Level Ratings use the rating of each individual span rather than a predefined line type rating. Improved Network Collapsing lets similar, not just identical, conductors be normalised and combined, which cuts the node count and solve time. ratingThreshold and simplifyPLSIThreshold can be used with or without Span Level Ratings, and also benefit models that do not use them.