SPDT Switch (Three-Phase)

Three-phase single-pole double-throw switch

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  • SPDT Switch (Three-Phase) block

Description

The SPDT Switch (Three-Phase) block models a three-phase single-pole double-throw switch that uses an external signal to connect each phase of the port ~1 with the corresponding phase of either port ~2 or ~3.

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

ConditionBlock BehaviorResistance Parameter Used
vT ≤ ThresholdEach phase of port ~1 is connected to the corresponding phase of port ~2 via internal resistance. Port ~3 is unconnected.Open conductance (port ~1 to port ~3). Closed resistance (port ~1 to port ~2)
vT > ThresholdEach phase of port ~1 is connected to the corresponding phase of port ~3 via internal resistance. Port ~2 is unconnected.Open conductance (port ~1 to port ~2). Closed resistance (port ~1 to port ~3)

Ports

Input

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Physical control port.

Dependencies

This port is visible only when Block Choice is set 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.

Expandable three-phase electrical conserving port.

Electrical conserving control port.

Dependencies

This port is visible only when Block Choice is set to Expanded three-phase ports| Electrical control port or Composite three-phase ports| Electrical control port.

Negative electrical conserving port.

Dependencies

This port is visible only when Block Choice is set to Expanded three-phase ports| Electrical control port or Composite three-phase ports| Electrical control port.

Parameters

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Resistance between ports ~1 and ~3 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.

Model 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.

Extended Capabilities

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

See Also

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Topics

Introduced in R2013b

Simscape Electrical Documentation

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