Circuit Breaker (Three-Phase)

Three-phase circuit breaker controlled by external signal

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Libraries:
Simscape / Electrical / Switches & Breakers

Description

The Circuit Breaker (Three-Phase) block models a three-phase circuit breaker that uses an external signal and phase current information to break an electrical circuit.

The table shows how the external signal vT and the Breaker Behavior parameter control the block behavior.

Condition		Block Behavior	Resistance Parameter Used
vT < Threshold		The breaker is closed. Each phase in the composite three-phase port ~1 connects to the corresponding phase in the port ~2.	Closed Resistance
vT ≥ Threshold	`Open when current crosses zero after vT >= Threshold`	When the current in any phase of the composite port ~1 crosses zero, the phase disconnects from the corresponding phase at port ~2. The breaker is open.	Open Conductance
vT ≥ Threshold	`Open when vT >= Threshold`	The breaker is open.	Open Conductance

Examples

Three-Phase Synchronous Machine Control

Three-Phase Synchronous Machine Control

Control and initialize a Synchronous Machine (SM). The test circuit shows the SM operating as a generator. The terminal voltage is controlled using an AVR and the speed is controlled using a governor.

Open Model

Three-Phase Custom Simplified Synchronous Machine

Three-Phase Custom Simplified Synchronous Machine

How simplify the custom Simscape™ synchronous machine model.

Open Model

Marine Full Electric Propulsion Power System

Marine Full Electric Propulsion Power System

A representative marine half-ship electrical power system with base load, hotel load, bow thrusters and electric propulsion.

Open Model

Ports

Input

vT — Scalar control port
physical signal

Scalar physical signal control port.

Dependencies

To enable this port, set the Control port parameter to PS.

Conserving

~1 — Three-phase port of side 1
electrical

Electrical conserving port representing the three phases of side 1. For more information, see Three-Phase Ports.

Dependencies

To enable this port, set the Electrical connection parameter to Composite three-phase ports.

~2 — Three-phase port of side 2
electrical

Electrical conserving port representing the three phases of side 2. For more information, see Three-Phase Ports.

Dependencies

To enable this port, set the Electrical connection parameter to Composite three-phase ports.

a1 — Phase `a` of side 1
electrical

Electrical conserving port associated with the phase a of side 1.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

b1 — Phase `b` of side 1
electrical

Electrical conserving port associated with the phase b of side 1.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

c1 — Phase `c` of side 1
electrical

Electrical conserving port associated with the phase c of side 1.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

a2 — Phase `a` of side 2
electrical

Electrical conserving port associated with the phase a of side 2.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

b2 — Phase `b` of side 2
electrical

Electrical conserving port associated with the phase b of side 2.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

c2 — Phase `c` of side 2
electrical

Electrical conserving port associated with the phase c of side 2.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

+ — Positive port
electrical

Positive electrical conserving port.

Dependencies

To enable this port, set the Control port parameter to Electrical.

- — Negative port
electrical

Negative electrical conserving port.

Dependencies

To enable this port, set the Control port parameter to Electrical.

Parameters

Electrical connection — Whether to model composite or expanded three-phase ports
`Composite three-phase ports` (default) | `Expanded three-phase ports`

Since R2026a

Whether to model composite or expanded three-phase ports.

Composite three-phase ports represent three individual electrical conserving ports with a single block port. You can use composite three-phase ports to build models that correspond to single-line diagrams of three-phase electrical systems.

Expanded three-phase ports represent the individual phases of a three-phase system using three separate electrical conserving ports.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	`port_option`
Values:	`"ee.enum.threePhasePort.composite"` (default) \| `"ee.enum.threePhasePort.expanded"`

Control port — Choose between physical signal input port or electrical conserving ports
`PS` (default) | `Electrical`

Since R2026a

Option to choose between a physical signal input port, vT, or electrical conserving ports, + and -.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	`control_port_option`
Values:	`"ee.enum.controlport.ps"` (default) \| `"ee.enum.controlport.elec"`

Closed resistance — Closed resistance
`0.001` `Ohm` (default)

Resistance between ports ~1 and ~2 when the breaker is closed.

Open conductance — Open conductance
`1e-6` `1/Ohm` (default)

Conductance between ports ~1 and ~2 when the breaker is open.

Threshold — Threshold voltage
`0.5` `V` (default)

Threshold voltage for the control port vT. The block uses the threshold voltage and the value of vT at the start of the simulation to determine whether the breaker is initially open or closed. If you set Breaker Behavior to Open when current crosses zero after vT >= Threshold, when the voltage rises above the threshold, the breaker opens each phase as its current crosses zero. If you set Breaker Behavior to Open when vT >= Threshold, the breaker opens each phase as soon as the voltage rises above the threshold. When the control port voltage falls below the threshold, the breaker closes.

Breaker Behavior — Breaker Behavior when vT rises above threshold
`Open when current crosses zero after vT >= Threshold` (default) | `Open when vT >= Threshold`

Breaker Behavior when the value at the control port vT is greater than or equal to the value of the Threshold parameter. The breaker can open either as soon as the voltage rises above the threshold, or when its current also crosses zero.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2013b

R2026a: The Modeling option parameter has changed

The Modeling option parameter has been replaced with the Electrical connection and Control port parameters. You can now also set the value of these parameters programmatically by using the set_param function.

If you created a model containing this block in an earlier release, the software now automatically sets the value of the Electrical connection and Control port parameters to the previous value of the Modeling option parameter.

See Also

Circuit Breaker | Circuit Breaker (with arc)

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