Distribution device models#

The OpenDSS compatibility reference lists the exact command and class boundary. This page describes the electrical role of each supported device group.

Network and source elements#

Circuit and VSource: Three-phase and single-phase Thevenin sources are derived from sequence or explicit impedance data. The source remains a physical network element and is not replaced by a slack-bus constraint.
ISource: A fundamental-frequency current source uses positive-, negative-, or zero-sequence phase rotation. Grounded and explicit second terminals are supported.
Equivalent: A multi-terminal Thevenin equivalent accepts coupled positive-sequence and zero-sequence impedance matrices.
Line and LineCode: Sequence parameters or full resistance, reactance, and capacitance matrices define coupled conductor behavior. A line can also have a fixed switch state.
LineGeometry, LineSpacing, WireData, CNData, and TSData: Physical conductor positions and material data define overhead, concentric-neutral, and tape-shield line models. The model can reduce neutral conductors when the source requests this behavior.

Transformers and shunts#

Transformer: Two or more windings support wye and delta connections, phase shifts, fixed taps, neutral impedance, anti-float admittance, and XSCArray leakage data.
AutoTrans: Two-winding and three-winding autotransformers retain their series and common winding relations. Fixed taps and leakage data are supported.
Reactor: Wye and delta reactors use rating data, scalar impedance, or full resistance and reactance matrices.
Capacitor: Fixed and stepped wye or delta banks are supported.

Loads, generators, and converters#

Load: Models 1 through 8 use the composed response laws described in Distribution load models.
Generator: Snapshot models 1 through 5 and 7 are supported. Model 3 enforces its voltage target until a reactive limit becomes active. Model 6 requires a user DLL and is rejected.
PVSystem: Snapshot models 1 and 2 include irradiance, temperature and efficiency curves, current limits, balanced-current projection, inverter cut-in and cut-out behavior, and inverter-rating priorities.
Storage: Snapshot models 1 and 2 resolve charging, discharging, idling loss, stored energy, reserve, efficiency, current, balance, and inverter-rating policies into one fixed operating point. Energy does not advance during a snapshot solve.
IndMach012: A three-phase induction machine couples positive-sequence and negative-sequence electrical response. Fixed-slip mode holds the entered slip. Variable-slip mode adjusts slip to enforce the active-power target.

Static controls#

RegControl: The control measures local or compensated voltage, compares it with a band, and changes a transformer tap within its declared limits. The final tap and ordered actions are returned in PhaseSolvedCase.
CapControl: Voltage, current, kvar, and power-factor measurements can switch a stepped capacitor bank. The final step state and ordered actions are returned.
SwtControl: A manual final state can open or close each controlled phase.

The control scheduler preserves deterministic static action order. Delays are used for ordering, but wall-clock waiting does not occur during a snapshot solve. A control iteration limit and oscillation detection provide explicit stop conditions.

Results and unsupported semantics#

Every supported element reports ordered conductor current, ordered conductor power, and total complex loss through the common phase result arrays. Controls also report their final state and action history.

An active class or property is rejected when its electrical behavior is not implemented. Shell commands, user DLLs, dynamics, harmonics, protection coordination, and interleaved edit-and-solve sequences are not approximated by the snapshot solver.