GDM has two system containers for two different engineering views of the grid. They share the same component-registration and persistence foundation, but they do not represent the same network boundary.
| Choose this model | It owns | Typical contents |
|---|---|---|
DistributionSystem | Distribution-network connectivity and feeder analysis | Distribution buses, feeders, lines, loads, DER, voltage sources, and time series |
SubstationSystem | Facility topology and station equipment | Substations, voltage levels, bays, bus sections, breakers, transformers, protection, metering, and station automation |
DistributionSubstation is a grouping component inside a distribution model. It
does not replace SubstationSystem, which models the station’s internal bays,
bus arrangement, and equipment.
How They Fit Together¶
A substation can feed one or more distribution feeder models. Keep these models separate when they are owned, built, or updated independently. When an analysis needs one connected network, join them at explicit feeder boundaries:
FeederBoundary.feeder_id matches a DistributionFeeder.name. When assembling
a complete network, source_equivalent_id names the feeder’s root bus in its
distribution model. The station and feeders can then be combined with
SubstationSystem.to_distribution_system().
There are two common workflows:
Expand one station in an existing feeder model. Replace a distribution transformer with a detailed substation using
DistributionSystem.replace_transformer_with_substation().Assemble a complete station and feeder set. Keep the station and feeder models separate, then combine them with
SubstationSystem.to_distribution_system()when a unified model is needed.
See Distribution System, Substation System, and Connecting Systems for the corresponding code and validation rules.