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SPMT Switch

Single-pole multiple-throw switch

Since R2020a

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  • SPMT Switch block

Libraries:
Simscape / Electrical / Switches & Breakers

Description

The SPMT Switch block models a single-pole multiple-throw switch. You can specify three to eight throw connections by setting the Number of throw ports parameter to the desired amount. If you only need one or two throw ports, see the SPST Switch and SPDT Switch blocks.

The switch control port physical signal, vT, specifies which throw port connects to the pole:

  • When vT is in the [-inf, 1.5] range, the pole always connects to throw port 1, n1.

  • When vT is between one and the number of throw ports, the signal value is rounded to the nearest integer. The pole then connects to the throw port that corresponds to the integer value.

  • When vT is higher than the number of throw ports, the pole always connects to the last throw port.

Open connections are modeled by a resistor with a value equal to the reciprocal of the Open conductance parameter value. Closed connections are modeled by a resistor with a value equal to the Closed resistance parameter value.

Faults

To model a fault in the SPMT Switch block, in the Faults section, click the Add fault hyperlink next to the fault that you want to model. In the Add Fault window, specify the fault properties. For more information about fault modeling, see Fault Behavior Modeling and Fault Triggering.

Assumptions and Limitations

  • The values of the open conductance and closed resistance are the same for all throw ports.

  • Switch dynamics and custom thresholds are not modeled.

Ports

Refer to the figure for port locations.

Input

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Signal that opens and closes the switch, specified as a physical signal.

Conserving

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Electrical conserving port associated with the common pole.

Electrical conserving port associated with the first throw.

Electrical conserving port associated with the second throw.

Electrical conserving port associated with the third throw.

Electrical conserving port associated with the fourth throw.

Dependencies

To enable this port, set Number of throw ports to 4, 5, 6, 7, or 8.

Electrical conserving port associated with the fifth throw.

Dependencies

To enable this port, set Number of throw ports to 5, 6, 7, or 8.

Electrical conserving port associated with the sixth throw.

Dependencies

To enable this port, set Number of throw ports to 6, 7, or 8.

Electrical conserving port associated with the seventh throw.

Dependencies

To enable this port, set Number of throw ports to 7 or 8.

Electrical conserving port associated with the eighth throw.

Dependencies

To enable this port, set Number of throw ports to 8.

Parameters

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Main

Number of throw connections.

Resistance between the p port and the throw ports when the switch is closed. The value must be greater than zero.

Conductance between the p port and the throw ports when the switch is open. The value must be greater than zero.

Faults

Option to add a stuck throw fault in the SPMT Switch block.

To add a fault, click the Add fault hyperlink.

Simulation time at which the block enters the faulted state.

Dependencies

To enable this parameter, in the Fault Inspector window, set Trigger Type to Timed.

This parameter appears in the Trigger section of the Fault Inspector window. For more information, see Set Fault Triggers.

Maximum current that is permitted to flow through the common port, above which a fault may be triggered.

To enable this parameter, in the Fault Inspector window, set Trigger Type to Behavioral.

This parameter appears in the Trigger section of the Fault Inspector window. For more information, see Set Fault Triggers.

Amount of time that the common port current must continuously exceed the maximum permissible current before a behavioral fault is triggered.

To enable this parameter, in the Fault Inspector window, set Trigger Type to Behavioral.

This parameter appears in the Trigger section of the Fault Inspector window. For more information, see Set Fault Triggers.

Extended Capabilities

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

Version History

Introduced in R2020a

See Also

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