Fault (3-phase)

Three-phase fault block. Applies a configurable fault (single-line-to-ground, line-to-line, double-line-to-ground, or three-phase) with a chosen fault resistance, on a timed window or under external trigger control.

Category: Three-Phase / Sources

Keywords: 3-phase, 3-ph, 3 ph, 3ph, three, three-phase, three phase, phase, ph, short, short circuit, SC, SLG, LL, LLG, LLL, ground fault

Ports

Name	Direction	Value type	Notes
bus	electrical_3ph	double
enable	input	double	Visible when trigger_mode == 'control'

Parameters

Name	Label	Type	Default	Units	Description
fault_type	Fault type	enum (A-G (1φ to gnd) / B-G (1φ to gnd) / C-G (1φ to gnd) / A-B (φ-φ) / B-C (φ-φ) / C-A (φ-φ) / AB-G (2φ to gnd) / BC-G (2φ to gnd) / CA-G (2φ to gnd) / ABC (3φ sym))	AG	—	Fault topology at the bus port. AG/BG/CG = single line-to-ground. AB/BC/CA = phase-to-phase. ABG/BCG/CAG = double line-to-ground. ABC = three-phase symmetrical. Ground topologies use the internal simulator ground (no external port).
fault_resistance	R fault	double	0.01	—	Fault path resistance (Ω). Typical: 0.001 - 0.1 (bolted), 1 - 50 (arcing).
trigger_mode	Trigger mode	enum (Timed window / Control input)	timed	—	`timed` = active in [t_trigger, t_clear]. `control` = follows `enable` input (≠0 = active). After deactivation, each phase waits for |i| < `i_threshold` before opening (current-zero clearing).
t_trigger	t trigger (s)	double	0.05	—	Fault activation time (s) for `timed` mode.
t_clear	t clear (s)	double	0.15	—	Clear-command time (s) for `timed` mode. Each phase waits independently for |i| < `i_threshold` before opening (avoids di/dt spike).
i_threshold	I clear threshold (A)	double	1	—	|i| below which a phase may open after deactivation. Larger = clears earlier; smaller = waits closer to natural zero. Phases clear independently. 0 = true current-zero (may delay up to one cycle).
measure_currents	Measure fault currents	enum (Off / On)	0	—	Emit per-phase fault currents (A) flowing from bus into the fault. Names per phase.
i_fault_name_a	Fault current name A	string	Ifa	—
i_fault_name_b	Fault current name B	string	Ifb	—
i_fault_name_c	Fault current name C	string	Ifc	—

Observables

Signal	Type	Default name	Enable	Description
i_fault_a	signal	from i_fault_name_a	measure_currents	Phase A fault current flowing from bus into fault (A).
i_fault_b	signal	from i_fault_name_b	measure_currents	Phase B fault current (A).
i_fault_c	signal	from i_fault_name_c	measure_currents	Phase C fault current (A).

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Implemented in C++ class SimCompElecTransformerFault (components/electrical/sim_comp_elec_transformer_fault/sim_comp_elec_transformer_fault.h).