Breaker (3-phase)

Three-phase circuit breaker — three independent poles (one per phase) sharing a single open/close command. Each pole acts as a small R_on resistance when closed and a very large R_off resistance when open. The command comes from a wired control input, a named signal (0 = open, > 0 = close), or a built-in time schedule that toggles all three poles open↔closed at each time in a list (starting from a chosen initial state — no wiring needed). When commanded to open, each pole independently holds closed until its own through-current can be interrupted — its magnitude falls to the Interrupt-current threshold, or its phase current crosses zero — so the three poles generally clear at slightly different instants (realistic AC behaviour); this per-pole clearing applies to a time-triggered open as well. Set the threshold large to open instantly under load, 0 to wait for a natural AC zero. A separate Load-flow state switch decides whether the power-flow (load-flow) analysis treats the breaker as a closed low-impedance branch between its two buses or leaves it out (open); it is independent of the time-domain command and t = 0 state. Optional per-phase current and open/closed-state observables. No arc model.

Category: Three-Phase / Switching

Ports

Name	Direction	Value type	Notes
left	electrical_3ph	double
right	electrical_3ph	double
ctrl	input	double	Visible when trigger_source == 0

Parameters

Config

Name	Label	Type	Default	Units	Description
resistance_on	R_on	double	0.001	Ohms (Ω, kΩ, MΩ)	Closed-state per-pole resistance. Pick a unit from the dropdown.
resistance_off	R_off	double	1000000000	Ohms (Ω, kΩ, MΩ)	Open-state per-pole resistance. Pick a unit from the dropdown.
trigger_source	Trigger source	enum (Control input / Named signal / Time triggered)	0	—	Where the shared open/close command comes from. `Control input`: a wired `ctrl` port (hidden for the other sources). `Named signal`: a portless signal resolved by name (GoTo / labelled wire / another component's observable), read 1-step delayed. `Time triggered`: a built-in schedule toggles all three poles open↔closed at each time on the Trigger time(s) list, starting from the Initial state (no wiring needed). For Control input / Named signal, 0 = open, any value > 0 = close, applied to all three poles.
trigger_signal_name	Trigger signal name	string	(empty)	—	Name of the published signal that commands all three poles when Trigger source is `Named signal` (0 = open, > 0 = close). Resolved through the shared name registry and read 1-step delayed. Blank reads 0 (breaker stays open).
trigger_times	Trigger time(s)	string	(empty)	—	Comma-separated trigger times in seconds, e.g. `2` or `2,4,6`. All three poles toggle state (open↔closed) at each time, starting from the Initial state. Blank = never toggles (stays at the Initial state for the whole run). A time-triggered open still respects the Interrupt current threshold below (instant by default).
initial_state	Initial state	enum (Open / Closed)	1	—	Breaker state at t = 0 (the state before the first trigger time), and the symbol drawn on the canvas (Closed = arm bridges the contacts; Open = arm lifted). Time-triggered mode only.
interrupt_current	Interrupt current	double	1000000000	A (A, kA)	Largest per-pole through-current the breaker can interrupt the instant it is commanded open. While opening, each pole stays closed until its |I| falls to this value OR its phase current crosses zero, then opens. Default is very large, so all poles open immediately under any load (an abrupt chop; the inductive L·di/dt shows up as a voltage spike). Set 0 to wait for each phase's natural current zero (ideal AC interruption); a small value models a vacuum breaker's chopping current. Note: with 0 on a DC current (no zero crossing) that pole stays closed.
loadflow_state	Load-flow state	enum (Open / Closed)	1	—	Breaker state seen by the power-flow (load-flow) analysis ONLY — it does not affect the time-domain run, the EMT t = 0 state, or the open/close command above. `Closed`: the breaker appears in the load-flow case as a low-impedance branch (R = R_on, per pole) tying its two buses, so power flows through it. `Open`: the breaker is left out of the load-flow case, disconnecting the two sides. To take effect, wire `left` and `right` to two different buses — a closed breaker whose ports are not both on buses is reported as an unconnected branch and skipped.
measure_current	Measure current	enum (Off / On)	0	—	Emit per-phase branch currents (A) flowing left → right as simulator observables.
measure_state	Measure state	enum (Off / On)	0	—	Emit each pole's actual state as a simulator observable (1 = closed, 0 = open). Useful because the poles lag the command — and each other — while waiting to interrupt.

Signal Names

Name	Label	Type	Default	Units	Description
current_name_a	Phase A current name	string	Ia	—	Signal name for Phase A branch current. Blank skips this phase.
current_name_b	Phase B current name	string	Ib	—	Signal name for Phase B branch current. Blank skips this phase.
current_name_c	Phase C current name	string	Ic	—	Signal name for Phase C branch current. Blank skips this phase.
state_name_a	Phase A state name	string	BRKa	—	Signal name for Phase A pole state (1 = closed, 0 = open). Blank skips this phase.
state_name_b	Phase B state name	string	BRKb	—	Signal name for Phase B pole state (1 = closed, 0 = open). Blank skips this phase.
state_name_c	Phase C state name	string	BRKc	—	Signal name for Phase C pole state (1 = closed, 0 = open). Blank skips this phase.

Observables

Signal	Type	Default name	Enable	Description
branchCurrent_a	signal	from current_name_a	measure_current	Phase A branch current, left → right (A).
branchCurrent_b	signal	from current_name_b	measure_current	Phase B branch current, left → right (A).
branchCurrent_c	signal	from current_name_c	measure_current	Phase C branch current, left → right (A).
breakerState_a	signal	from state_name_a	measure_state	Phase A pole state (1 = closed, 0 = open).
breakerState_b	signal	from state_name_b	measure_state	Phase B pole state (1 = closed, 0 = open).
breakerState_c	signal	from state_name_c	measure_state	Phase C pole state (1 = closed, 0 = open).