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SPST Switch (Three-Phase)

Three-phase single-pole single-throw switch

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  • SPST Switch (Three-Phase) block

Libraries:
Simscape / Electrical / Switches & Breakers

Description

The SPST Switch (Three-Phase) block models a three-phase single-throw switch that uses an external signal to connect each phase of port ~1 with the corresponding phase of port ~2 via internal resistance.

The table shows how the external signal vT controls the block behavior.

ConditionBlock BehaviorResistance Parameter Used
vT ≤ThresholdThe switch is open. Each phase in the composite three-phase port ~1 connects to the corresponding phase in the port ~2 via large internal resistance.Open conductance
vT >ThresholdThe switch is closed. Each phase in the composite three-phase port ~1 connects to the corresponding phase in the port ~2 via small internal resistance.Closed resistance

Examples

Three-Phase Asynchronous Machine Starting

Three-Phase Asynchronous Machine Starting

Model a wye-delta starting circuit for an induction machine. When the supply is connected to the machine via switch S1, switch S2 is initially off resulting in the machine being connected in a wye configuration. Once the machine is close to synchronous speed, switch S2 is operated thereby reconnecting the machine in a delta configuration. The higher impedance seen by the supply when the motor is in wye configuration reduces the starting current, and causes less disruption to other connected loads.

Ports

Input

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Physical control port.

Dependencies

To enable this port, set Modeling option to Expanded three-phase ports | PS control port or Composite three-phase ports | PS control port.

Conserving

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Expandable three-phase electrical conserving port.

Expandable three-phase electrical conserving port.

Electrical conserving control port.

Dependencies

To enable this port, set Modeling option to Expanded three-phase ports| Electrical control port or Composite three-phase ports| Electrical control port.

Parameters

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Whether to model composite or expanded three-phase ports and physical signal or electrical control ports.

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

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

Threshold voltage for the control port vT. When the voltage is above the threshold, the switch is closed.

Extended Capabilities

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

Version History

Introduced in R2013b

See Also

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