modelDj
Junction diode model of Ebers-Moll BJT
Extends from Interfaces.PassiveOnePort (Partial model invoking one bondgraphic connector).
Information
The junction diode element is a passive OnePort element. It inherits the effort and flow variables from the passive OnePort. Junction diodes are a special class of non-linear resistors.The junction diode model is a simple diode with an exponential characteristic. The diode formula essentially is:
f = Is*(exp(e/Vt) - 1)
However, if the exponent e/Vt reaches either an upper limit EMax or a lower limit Emin, the diode characterisic is linearly continued to avoid overflow or underflow, respectively.
The causality of the junction diode element is free.
Potential variables: e: Bondgraphic effort variable f: Bondgraphic flow variable, normalized positive for flows into the model Parameters: Is: Transport saturation current (default value = 1e-16 Amp) Vt: Thermal voltage (default value = 0.02585 Volt) EMin: Minimum exponent (default value = -100) EMax: Maximum exponent (default value = 40)
Equations:
ExMin = exp(EMin)
ExMax = exp(EMax)
f = if (e/Vt < EMin) then Is*(ExMin*(e/Vt - EMin + 1) - 1) else
if (e/Vt > EMax) then Is*(ExMax*(e/Vt - EMax + 1) - 1) else Is*(exp(e/Vt) - 1)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.SIunits.Current | Is | 1.e-16 | Transport saturation current |
| Modelica.SIunits.Voltage | Vt | 0.02585 | Voltage equivalent of temperature (kT/qn) |
| Real | EMin | -100 | if x < EMin, the exp(x) function is linearized |
| Real | EMax | 40 | if x > EMax, the exp(x) function is linearized |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| BondLib.Interfaces.BondCon | BondCon1 (from PassiveOnePort) | Bond graph connector |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | e (from PassiveOnePort) | Bondgraphic effort | |
| Real | f (from PassiveOnePort) | Bondgraphic flow |