SIMPLORER User Manual V6.0 - FER-a

SIMPLORER 6.0 — Manual 129
There are five simulation levels regarding the electrical behavior. The level is set at the parameter
TYPE_DYN:
TYPE_DYN=0
Only the static behavior is calculated. The charges at the capacitances are ignored, no
switching behavior.
TYPE_DYN=1
In addition to the static behavior, charging and discharging of the junction and diffusion capacitance
are calculated. Values of parasitic capacitances at the terminals can be defined.
TYPE_DYN=2
If this level is selected, the model is expanded by a current source that models the tail current.
TYPE_DYN=3
The tail current is calculated considering the junction temperature and the influence of the
collector current on the time constant of the tail current.
TYPE_DYN=4
At this level the dependency of the tail current on the collector-emitter voltage is taking into
account in addition to all other effects modeled in the previous levels.
Please note that the value of the voltage influencing the tail current is taken from the previous
switching-off. That is why the level does not give proper results for fault simulation and should
be used only for investigations of periodic switching processes.
Electrical Behavior Level, Type DYN=0
For the calculation of the static FET current a distinction is made between the linear region
and the pinch-off region. The so-called saturation voltage is given with
Vsat A_FET ( VGS – VP) M_FET
= ⋅
The transition happens when the drain current satisfies the following equation
Isat k
-- ( V
2 GS – VP) N_FET
= ⋅
Within the linear region the following equation is used
ID Isat ( 1+ KLM⋅VDS) 2 V ⎛ DS
– ---------- ⎞
⎝ ⎠
VDS = ⋅ ⋅ ⋅ ----------
and for pinch-off applies
ID = Isat ⋅ ( 1 + KLM ⋅ VDS) V sat
The static IGBT current is calculated from
IC =
ID ⋅ BN V sat
The transistor constant k, the pinch-off voltage VP and the current gain BN are temperature
dependent. Their values at the nominal temperature TEMP0 are parameters of the model.
During the simulation their actual values are calculated taking into account the actual value
of the junction temperature taken from the thermal model.