Hi guys,
I face a problem with a boost converter.
When my igbt is switched on, then I observe an overshoot at the output voltage. I put a snubber
capacitor, but this is not about it (this is actually useful at the switch off state). I googled it, and
found some specs from commercial products characteristic curves with the same "problem". This
overshoot phenomenon duration is of about 10us, which is comparable with my switching frequency.
Describing better my situation:
From the moment that the pulse is on, an overshoot is observed at the output voltage like oscillation,
when this finishes, the igbt seems to switch on and the inductor current increases. After that everything
is ok. When the output voltage is 30V, the peak value of the overshoot is of about 33-35V. At higher
voltages this is more intense.
My diode is hyperfast (some 20-30ns) and my igbt has been tested under other kind of circuits and
it seems to be everything ok, until all these have to operate together.
(test case: L = 1.2mH - 2mH, Cout = 470uF, Rload = 13.6Ohm, Iin_average = 2-3 A, Vin_average = 20V)
A larger capacitor may solve my problem? Has anyone else faced the same thing? You know the answer
because you solved also my previous query with my igbts...
Thank you in advance