SIMPLORER User Manual V6.0 - FER-a

Equivalent Line
SIMPLORER 6.0 — Manual 291
>>Basics>Tools>Characteristics
V limit stands for the intersection of the forward and reverse characteristic and is calculated by
the program itself. With the equivalent line the nonlinear behavior of switching components
is represented most simply. However, in some rare circumstances numeric instabilities can
occur with the equivalent line when switching from one branch to the other.
vt () – VF
I = ----------------------- for v() t ≥ V
RB
limit
vt ()
I = --------- for v() t < V
RR
limit
Dialog Settings
«Forward Voltage [V]»«Bulk Resistance [Ohm]»«Reverse Resistance [Ohm]»
Defines the coefficients forward voltage, bulk resistance, and reverse resistance. Common
parameter types. Enter a numerical value, a variable, or an expression in the text box.
Component Parameters
Description [Unit] Parameter Name Data Type
Forward Voltage [V] VF real
Bulk Resistance [Ohm] RB real
Reverse Resistance [Ohm] RR real
Component Outputs
Description [Unit] Parameter Name Data Type
Value of the Equivalent Line VAL real
Exponential Function
>>Basics>Tools>Characteristics
With the exponential function, the static behavior of switched components is represented accurately
over a wide range. However, the use of exponential functions without specifying a
bulk resistance RB is not very practical for semiconductor components in power electronics.
For these cases, the bulk resistance must be inserted by the user as a separate component in
the circuit.
vt ()
---------
⎛ VT ⎞
it () = ISAT ⋅ ⎜e– 1⎟
for v() t ≥ 0
⎝ ⎠
it ()
vt ()
=
--------- for v() t < 0
RR
Dialog Settings
«Thermal Voltage [V]»«Saturation Current [A]»«Reverse Resistance [Ohm]»
Defines the coefficients thermal voltage, saturation current, and reverse resistance. Common
parameter types. Enter a numerical value, a variable, or an expression in the text box.