Support matrix

This matrix shows how gpf handles each device family and control mode during a power-flow solve. It uses the solver's validation data, so each support status and issue code matches what gpf reports for a case.

The Support column shows whether gpf models a device directly, uses an approximation, keeps its input setting, rejects the case, or excludes the record from the power-flow calculation. The definitions below summarize each outcome. See What the solver does with a device in the gpf User Guide for more detail.

Native

The converged result satisfies the supported device model and control.

Approximated

Solved with the stated approximation. A coded warning is attached to the solution so the approximation is visible per case.

Locked at input

The device is held at its input state and its control is not stepped. A coded warning is attached to the solution.

Rejected

The case is refused before the solve, with a coded error naming each offending record.

No power-flow effect

Carried through parsing and writing; does not change the solution.

The codes named in the tables are gpf.IssueCode members produced by gpf.validate_case, which runs automatically before every solve. They are stable identifiers: tests can assert on them and integrations can match on them instead of parsing message text.

Buses

Feature	Support	Notes
Bus types 1/2/3 (PQ/PV/swing)	Native	This feature is supported.
Type 4 (isolated) buses	Native	This feature is supported. The case check reports ISOLATED_BUS.
An island without a swing bus	Rejected	This feature is not supported for this calculation. The case check reports ISLAND_NO_SWING.

Loads

Feature	Support	Notes
Constant-power load (PL/QL)	Native	This feature is supported.
Constant-current and constant-admittance components (IP/IQ/YP/YQ)	Native	This feature is supported.

Generators

Feature	Support	Notes
PV and swing machines with reactive limits (QT/QB)	Native	This feature is supported.
Remote voltage regulation (IREG)	Native	This feature is supported.
Wind machine modes (WMOD=1/2/3)	Native	This feature is supported.

Branches

Feature	Support	Notes
AC branches (pi model with line shunts)	Native	This feature is supported.
Zero- and near-zero-impedance ties	Native	This feature is supported.
System switching devices (v34+)	Native	This feature is supported.

Transformers (two-winding)

Feature	Support	Notes
Off-nominal taps, phase shift, CW/CZ/CM codes, magnetizing admittance	Native	This feature is supported.
Voltage-band tap control (COD1=1)	Native	This feature is supported.
Reactive-flow tap control (COD1=2)	Native	This feature is supported.
Active-power phase-shift control (COD1=3)	Native	This feature is supported.
Negative COD1 (control disabled)	Native	This feature is supported.
DC-line and asymmetric-flow tap modes (COD1=4/5)	Locked at input	The entered state is retained for this calculation. The case check reports XFMR_COD_UNSUPPORTED.
Impedance-correction tables (TAB1)	Native	This feature is supported.
Single-point or non-monotonic impedance-correction tables	Approximated	This feature is supported with limitations. Review the case findings. The case check reports IMPCOR_TABLE_IGNORED.
References to missing impedance-correction tables	Approximated	This feature is supported with limitations. Review the case findings. The case check reports IMPCOR_TABLE_MISSING.

Transformers (three-winding)

Feature	Support	Notes
Three-winding transformers	Native	This feature is supported.
Winding tap control (COD=1/2)	Native	This feature is supported.
Winding phase-shift control (COD=3)	Locked at input	The entered state is retained for this calculation. The case check reports XFMR_3W_PS_CONTROL_DROPPED.
Winding control modes COD=4/5	Locked at input	The entered state is retained for this calculation. The case check reports XFMR_COD_UNSUPPORTED.

Shunts

Feature	Support	Notes
Fixed bus shunts	Native	This feature is supported.

Switched shunts

Feature	Support	Notes
Fixed mode (MODSW=0)	Native	This feature is supported.
Discrete voltage control (MODSW=1)	Native	This feature is supported.
Continuous voltage control (MODSW=2)	Native	This feature is supported.
Plant reactive-band control (MODSW=3)	Native	This feature is supported.
Converter-commanded control (MODSW=4)	Locked at input	The entered state is retained for this calculation. The case check reports SWSHUNT_MODSW4_LOCKED.
Cascaded shunt control (MODSW=5)	Locked at input	The entered state is retained for this calculation. The case check reports SWSHUNT_MODSW5_LOCKED.
FACTS-commanded control (MODSW=6)	Locked at input	The entered state is retained for this calculation. The case check reports SWSHUNT_MODSW6_LOCKED.

HVDC (two-terminal)

Feature	Support	Notes
Line-commutated links with power or current setpoint (MDC=1/2)	Native	This feature is supported.
Blocked links (MDC=0)	Native	This feature is supported.
Capacitor-commutated converters (XCAPR/XCAPI > 0)	Approximated	This feature is supported with limitations. Review the case findings. The case check reports TWOTERMDC_CCC_APPROXIMATED.

HVDC (VSC)

Feature	Support	Notes
VSC DC lines (MDC=1)	Native	This feature is supported.

HVDC (multi-terminal)

Feature	Support	Notes
Multi-terminal DC networks	Rejected	This feature is not supported for this calculation. The case check reports MTDC_UNSUPPORTED.

FACTS

Feature	Support	Notes
Shunt devices in voltage control (STATCOM, MODE=1)	Native	This feature is supported.
Series devices in P/Q flow control (UPFC, MODE=1)	Native	This feature is supported.
STATCOM modes other than 1	Rejected	This feature is not supported for this calculation. The case check reports FACTS_STATCOM_MODE_UNSUPPORTED.
UPFC modes other than 1	Rejected	This feature is not supported for this calculation. The case check reports FACTS_UPFC_MODE_UNSUPPORTED.

Area interchange

Feature	Support	Notes
Net-interchange control (tie flows / tie flows and loads)	Native	This feature is supported.

Network metadata

Feature	Support	Notes
Zone, owner, and inter-area-transfer records	No power-flow effect	The application preserves this data but does not use it in the calculation.
Multi-section line groupings	No power-flow effect	The application preserves this data but does not use it in the calculation.
Load types and interfaces (v36)	No power-flow effect	The application preserves this data but does not use it in the calculation.
Sequence data files (fault-analysis sidecar)	No power-flow effect	The application preserves this data but does not use it in the calculation.
Substation node-breaker topology (v34+)	No power-flow effect	The application preserves this data but does not use it in the calculation. The case check reports SUBSTATION_TOPOLOGY_UNAPPLIED.

Fault analysis (sequence lowering)

Feature	Support	Notes
Two-winding zero-sequence connection codes 18, 19, 21, 22	Native	This feature is supported.
Center-tapped two-phase modeling (SCNRML=0)	Rejected	This feature is not supported for this calculation. The case check reports SEQ_CENTER_TAPPED_UNSUPPORTED.
Varistor-protected series capacitors (SCTYP=1 with IPR, MOV system record)	Native	This feature is supported.
Transformer phase-shift angles in sequence networks	Approximated	This feature is supported with limitations. Review the case findings. The case check reports SEQ_PHASE_SHIFT_APPROXIMATED.

Fault analysis (IEC 60909)

Feature	Support	Notes
Standard-method supplemental data files (.iec) and the IEC 60909 equivalent-voltage-source method	Approximated	This feature is supported with limitations. Review the case findings. The case check reports IEC_CORRECTION_INCOMPLETE.
Converter-interfaced wind/PV sources (.iec MCTYPE 4/5/6)	Approximated	This feature is supported with limitations. Review the case findings. The case check reports IEC_CORRECTION_INCOMPLETE.

Fault analysis (results & reporting)

Feature	Support	Notes
Fault-study result surface, contribution detail, and delta report	Native	This feature is supported.

Other devices

Feature	Support	Notes
Voltage droop control (v36)	Native	This feature is supported.
Induction machines	Native	This feature is supported.
GNE devices	No power-flow effect	The application preserves this data but does not use it in the calculation. The case check reports GNE_DEVICE_NOT_EVALUATED.

Optimal power flow

Feature	Support	Notes
Piecewise-linear and up to quadratic cost curves	Native	This feature is supported.
Cubic or higher polynomial cost and non-standard cost models	Rejected	This feature is not supported for this calculation. The case check reports OPF_COST_UNSUPPORTED.