SIMPLORER User Manual V6.0 - FER-a

4
5
124 Modeling with Circuit Components
Diffusion capacitance:
CDIFF TAU dI ( JNCT)
⋅ -----------------------dV
( JNCT)
TAU I =
( JNCT + IS)
= ⋅ ------------------------------
M⋅VT To damp the oscillations that occur in the system, additional damping resistances are placed
in the diode model. The value of the damping resistance depends on the parameter DAMP-
ING, the value of the parasitic inductance and the values of the internal capacitances.
Damping resistance:
L
RDAMP =
DAMPING ⋅ ------------
CV ( )
Component Parameters (+ Parameters of TYPE DYN=0)
Description [Unit] Parameter Name Data Type
Nominal Blocking Voltage [V] VNOM real
Nominal Current [A] INOM real
Total Junction Capacitance at 0V [F] C0_JNCT real
Diffusion Potential [V] VDIFF_JNCT real
Capacitance Exponent [/] ALPHA_JNCT real
Influence of constant Capacitance [0…1] [/] DELTA_JNCT real
Effective Lifetime [s] TAU real
Exponential Temperature Coefficient of TAU [/] ALPHA_TAU real
Linear Current Coefficient of TAU [/] KAPPA_TAU real
Linear Voltage Coefficient of TAU [/] SIGMA_TAU real
Parasitic Inductance [H] L real
Damping Factor [/] DAMPING real
Electrical Behavior Level, Type DYN=2,3
The integral of the reverse recovery current is determined by the parameter TAU. Form factors
define the curve of the reverse recovery current. The Electrical Behavior Level to 2 and 3 represent
two different characteristics. In both the reverse recovery is separated into five sections.
The maximum current Irrmax, and the time ts, when Irrmax is reached, are calculated
from the reverse recovery charge and the form factors.
1: From zero crossing of diode current until the level R1*Irrmax is reached. The current follows
an exponential function with the time constant TAU.
2: The current follows a sine wave function until Irrmax is reached.
3: The current follows a cosine function. This section lasts for SF1*ts. At its end the current
is at the level R2*Irrmax.
4: If the Electrical Behavior Level is set to '2' the current follows an exponential function. For
level 3 a linear function is used. Section 4 ends SF2*ts after Irrmax was reached. The current
at the end of section 4 is R3*Irrmax.
5: A quadratic function is used until the current reaches zero again.