Influence of the stray inductanceon the switching behaviour
During the IGBT turn-off process the followingapplies:
there is, the higher the collector-emitter voltageovershoot.
there is, the slower will the collector current drop before reaching
the tail current region. Meaning the same as a reduced
there is the less pronouncedwill the tail current be.
The more L
there is, the higher the turn-off losses E
. In the example o
the turn-off losses with L
70nH are approx. 145mJ. Whereas 170mJ
of switchingenergy occurswith L
As advantageous the stray inductance may be during the IGBT turn-on, as severe are
the effects at the time of turn-off. The following looks at two aspects. The first point
pertains to the resulting switching over-voltage, which, in combination with the
commutation stray inductance, limits the maximum DC-bus voltage, and/or the