SPST Switch
Single-pole single-position switch.
blockType: AcausalElectricPowerSystems.Switches.SPSTSwitch
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Description
Block SPST Switch simulates a single-phase single-position switch:
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When the control signal does not exceed Threshold, the switch is open. In this case, the p port is connected to the n port via the conductivity specified by the Open conduction parameter.
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When the control signal exceeds Threshold, the switch is closed. In this case, port p is connected to port n through the resistance set by the parameter Closed resistance.
When the Threshold width parameter is non-zero, the switch’s conductivity smoothly changes between the off and on states. The value of the Threshold width parameter determines the sharpness of the transition between switch states according to the formulas:
The block uses the function since its derivative is zero at and .
Setting a small positive value of Threshold width can contribute to solver convergence in some models, especially if the signal of the control port vT is continuously changing depending on other parts of the circuit. However, setting a non-zero Threshold width value does not allow linear optimization with switching in the solver. Therefore, if the rest of the chain is linear, set the value of the Threshold width parameter to zero.
Type of switch shutter control
In the component, it is possible to select the type of control of the switch shutter using the Modeling option:
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Signal control port — a signal coming to the vT port is received as a control signal.
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Electrical control port — the potential difference at the additional electrical ports is taken as the value of the control signal.
Entrance
vT — pass control port:q[<br>] scalar
A signal that controls the status of the switch.
Dependencies
To use this port, set the Modeling option to Signal control port.
Non-directional
p — positive pass port:q[<br>] electric
The electrical port.
n — negative pass port:q[<br>] electric
The electrical port.
+ — positive pass port:q[<br>] electric
The electrical port connected to the positive terminal. It is used in the voltage control mode.
Dependencies
To use this port, set the Modeling option to Electrical control port.
− — negative pass port:q[<br>] electric
The electrical port connected to the negative terminal. It is used in the voltage control mode.
Dependencies
To use this port, set the Modeling option to Electrical control port.
Parameters
Modeling option — setting the scalar or electrical control port
Signal control port (default) | Electrical control port
Determines what is used to control the state of the switch: a signal or a potential difference on the control legs.
Closed resistance — resistance of the closed pass switch:q[<br>] 0.01 Ohms (default) | positive scalar
Resistance between ports p and n when the switch is closed.
Open conduction — open circuit breaker conductivity
1e−6 1/ohm (default) | positive scalar
The conductivity between ports p and n when the switch is open.
Threshold — threshold voltage
0.5 V (default)
The threshold voltage above which the switch turns on.
Threshold width — the width of the pass threshold:q[<br>] 0 (default)
The minimum voltage increase is above the threshold value, which will switch the switch from a fully open state to a fully closed one.