LIBRARY

Analog.Basic.VariableResistor

Ideal linear electrical resistor with variable resistance.

The resistance value R is provided as an external input signal. An optional linear temperature coefficient alpha adjusts the actual resistance based on the heat port temperature:

$$R_{actual}=R\cdot (1+\alpha \cdot (T_{heatPort}-T_{ref}))$$

The electrical behavior follows Ohm's law:

$$v=R_{actual}\cdot i$$

Power dissipated in the resistor is transferred as heat through the thermal port heat_port.

Corresponds to Modelica.Electrical.Analog.Basic.VariableResistor.

This component extends from ElectricalComponents.Analog.Interfaces.OnePort

Usage

ElectricalComponents.Analog.Basic.VariableResistor(T_ref=300.15, alpha=0.0)

Parameters:

Name	Description	Units	Default value
T_ref	Reference temperature	K	300.15
alpha	Linear temperature coefficient of resistance	1/K	0

Connectors

• p - This connector represents an electrical pin with voltage and current as the potential and flow variables, respectively. (Pin)

• n - This connector represents an electrical pin with voltage and current as the potential and flow variables, respectively. (Pin)

• R - This connector represents a real signal as an input to a component (RealInput)

• heat_port - This connector represents a thermal port with temperature and heat flow as the potential and flow variables, respectively. (HeatPort)

Variables

Name	Description	Units
v	Voltage across the component (between pin p and pin n).	V
i	Current flowing through the component (from pin p to pin n).	A
R_actual	Actual resistance accounting for temperature	Ω
LossPower	Power dissipated in the resistor	W

Behavior

$$\begin{array}{rl}v\left(t\right)& =\mathtt{p}\mathtt{.}\mathtt{v}\left(t\right)-\mathtt{n}\mathtt{.}\mathtt{v}\left(t\right)\\ i\left(t\right)& =\mathtt{p}\mathtt{.}\mathtt{i}\left(t\right)\\ \mathtt{p}\mathtt{.}\mathtt{i}\left(t\right)+\mathtt{n}\mathtt{.}\mathtt{i}\left(t\right)& =0\\ \mathtt{R}\mathtt{\_}\mathtt{actual}\left(t\right)& =(1+(-\mathtt{T}\mathtt{\_}\mathtt{ref}+\mathtt{heat}\mathtt{\_}\mathtt{port}\mathtt{.}\mathtt{T}\left(t\right))\mathtt{alpha})R\left(t\right)\\ v\left(t\right)& =i\left(t\right)\mathtt{R}\mathtt{\_}\mathtt{actual}\left(t\right)\\ \mathtt{LossPower}\left(t\right)& =v\left(t\right)i\left(t\right)\\ \mathtt{heat}\mathtt{\_}\mathtt{port}\mathtt{.}\mathtt{Q}\mathtt{\_}\mathtt{flow}\left(t\right)& =-\mathtt{LossPower}\left(t\right)\end{array}$$

Source

"""
Ideal linear electrical resistor with variable resistance.

The resistance value `R` is provided as an external input signal.
An optional linear temperature coefficient `alpha` adjusts the
actual resistance based on the heat port temperature:

math R_{actual} = R \cdot (1 + \alpha \cdot (T_{heatPort} - T_{ref}))

The electrical behavior follows Ohm's law:

math v = R_{actual} \cdot i

Power dissipated in the resistor is transferred as heat through
the thermal port `heat_port`.

Corresponds to `Modelica.Electrical.Analog.Basic.VariableResistor`.
"""
component VariableResistor
  extends ElectricalComponents.Analog.Interfaces.OnePort
  "Resistance input signal"
  R = RealInput() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 450, "y1": -100, "x2": 550, "y2": 0, "rot": 90}
      },
      "tags": []
    }
  }
  "Thermal port for heat exchange"
  heat_port = HeatPort() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 460, "y1": 950, "x2": 560, "y2": 1050, "rot": 0}
      },
      "tags": []
    }
  }
  "Reference temperature"
  parameter T_ref::Temperature = 300.15
  "Linear temperature coefficient of resistance"
  parameter alpha::LinearTemperatureCoefficient = 0.0
  "Actual resistance accounting for temperature"
  variable R_actual::Resistance
  "Power dissipated in the resistor"
  variable LossPower::Power
relations
  assert((1 + alpha * (heat_port.T - T_ref)) >= 1e-15, "Temperature outside scope of model!")
  R_actual = R * (1 + alpha * (heat_port.T - T_ref))
  v = R_actual * i
  LossPower = v * i
  heat_port.Q_flow = -LossPower
metadata {
  "Dyad": {
    "labels": [{"label": "$(instance)", "x": 500, "y": 1100, "rot": 0}],
    "icons": {"default": "dyad://ElectricalComponents/Resistor.svg"}
  }
}
end

Flattened Source

"""
Ideal linear electrical resistor with variable resistance.

The resistance value `R` is provided as an external input signal.
An optional linear temperature coefficient `alpha` adjusts the
actual resistance based on the heat port temperature:

math R_{actual} = R \cdot (1 + \alpha \cdot (T_{heatPort} - T_{ref}))

The electrical behavior follows Ohm's law:

math v = R_{actual} \cdot i

Power dissipated in the resistor is transferred as heat through
the thermal port `heat_port`.

Corresponds to `Modelica.Electrical.Analog.Basic.VariableResistor`.
"""
component VariableResistor
  "Positive electrical pin."
  p = Pin() {
    "Dyad": {
      "placement": {"icon": {"iconName": "pos", "x1": -50, "y1": 450, "x2": 50, "y2": 550}}
    }
  }
  "Negative electrical pin."
  n = Pin() {
    "Dyad": {
      "placement": {"icon": {"iconName": "neg", "x1": 950, "y1": 450, "x2": 1050, "y2": 550}}
    }
  }
  "Voltage across the component (between pin p and pin n)."
  variable v::Voltage
  "Current flowing through the component (from pin p to pin n)."
  variable i::Current
  "Resistance input signal"
  R = RealInput() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 450, "y1": -100, "x2": 550, "y2": 0, "rot": 90}
      },
      "tags": []
    }
  }
  "Thermal port for heat exchange"
  heat_port = HeatPort() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 460, "y1": 950, "x2": 560, "y2": 1050, "rot": 0}
      },
      "tags": []
    }
  }
  "Reference temperature"
  parameter T_ref::Temperature = 300.15
  "Linear temperature coefficient of resistance"
  parameter alpha::LinearTemperatureCoefficient = 0.0
  "Actual resistance accounting for temperature"
  variable R_actual::Resistance
  "Power dissipated in the resistor"
  variable LossPower::Power
relations
  v = p.v - n.v
  i = p.i
  p.i + n.i = 0
  assert((1 + alpha * (heat_port.T - T_ref)) >= 1e-15, "Temperature outside scope of model!")
  R_actual = R * (1 + alpha * (heat_port.T - T_ref))
  v = R_actual * i
  LossPower = v * i
  heat_port.Q_flow = -LossPower
metadata {
  "Dyad": {
    "labels": [{"label": "$(instance)", "x": 500, "y": 1100, "rot": 0}],
    "icons": {"default": "dyad://ElectricalComponents/Resistor.svg"}
  }
}
end

Test Cases

No test cases defined.

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