Swend
Full Member level 4
- Joined
- May 14, 2019
- Messages
- 237
- Helped
- 10
- Reputation
- 20
- Reaction score
- 9
- Trophy points
- 18
- Location
- Roskilde, Denmark
- Activity points
- 2,304
you have not plotted Vgate-Vemitter. Looking at Vgate alone is meaningless. You ask why the cap currents are so high - can you not see the IGBT is shorting them at turn on? this also contributes to Vemitter rise at turn on - as I said above ....
look on your schematic where it says "G" and again where it says "E" plot (Ve-Vg) this is the true gate voltage ...
their di/dt is higher because they can reach a much higher I - i.e not limited by 30 ohms ...
Emitter degeneration was also my guess, but in the present simulation, the effect of parasitic inductances is relatively small due to the moderate gate voltage rise time.
I don't understand however the purpose of the simulation related to your work. It's all about dealing with huge gate driver skew, in the present example 100 ns. If you don't have it, you don't need large dynamic voltage sharing capacitors and thus don't experience high discharge currents.
Voltage sharing means may be necessary, depending on the application. The 100 ns delay skew assumed in the simulation is unrealistically large for modern gate driver circuits.
almost impossible to help without a clear schematic ...
- - - Updated - - -
leakage currents are most likely getting to the gates above 3kV just enough to start current thru the IGBT's ...
Can you convince us that the circuit including gate driver and driver supply has sufficient insulation strength for 3 kV? The Infineon driver is e.g. specified with +/-1200V only.I can not increase supply voltage above 3KV, none of the supplies I tried (NST,OBIT,FB all 20-40mA) could do it, they all stopped at 3KV regardless of how much I cranked the voltage up.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?