IGBT overshoot reduction

[ElectroUser]

Hi,
I am using an IGBT for experimental purposes. I am using Intenational rectifiers IRG4PC40W rated at 600V 20A on a simple resistive load. Using an 220 Ohm gate resistor i am getting a 80V overshoot with 20V Vce and 2A Ic. Can someone enlighten me why am i getting such a big overshoot. Can it be the circuit board? I have tried to keep the connections as short as i can but will a better circuit board reduce the overshoot?

Thanks in advance.

 

[Optikon]

Hi,
I am using an IGBT for experimental purposes. I am using Intenational rectifiers IRG4PC40W rated at 600V 20A on a simple resistive load. Using an 220 Ohm gate resistor i am getting a 80V overshoot with 20V Vce and 2A Ic. Can someone enlighten me why am i getting such a big overshoot. Can it be the circuit board? I have tried to keep the connections as short as i can but will a better circuit board reduce the overshoot?

Thanks in advance.

Draw your schematic please. Also the resistive load, would that happen to be a wire-wound power type? (read.. inductive)

 

[ElectroUser]

Yes it is. Never thought of that. Below there is a link of the resistor I am using. CGS HSC100 10R. Looked at the datasheet and they have some low induction ones. We dont have any in the labs so i will have to buy one.

https://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=652519&N=401


Now I will have to try this with higher power (6amps 200V) with load a resistor bank 2.4KW. Is there a way to measure the inductance of the bank? or is it better to try and find a better less inductive load (bit hard for such power)?

_____
-----|Rload|-----(Vanode)
_____ /
---|Rgate|----[IGBt
| \
| |
(Vg) |
| |
___ ___
- -

Thank you for your quick reply.

 

[ElectroUser]

Yes it is. Never thought of that. Below there is a link of the resistor I am using. CGS HSC100 10R. Looked at the datasheet and they have some low induction ones. We dont have any in the labs so i will have to buy one.

https://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=652519&N=401


Now I will have to try this with higher power (6amps 200V) with load a resistor bank 2.4KW. Is there a way to measure the inductance of the bank? or is it better to try and find a better less inductive load (bit hard for such power)?

It is just an IGBT with a resistor on the anode connected on the positive of the supply voltage. Nothing special.

Thank you for your quick reply.

 

[Optikon]

Yes it is. Never thought of that. Below there is a link of the resistor I am using. CGS HSC100 10R. Looked at the datasheet and they have some low induction ones. We dont have any in the labs so i will have to buy one.

https://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=652519&N=401


Now I will have to try this with higher power (6amps 200V) with load a resistor bank 2.4KW. Is there a way to measure the inductance of the bank? or is it better to try and find a better less inductive load (bit hard for such power)?

It is just an IGBT with a resistor on the anode connected on the positive of the supply voltage. Nothing special.

Thank you for your quick reply.

If the inductance is large enough, it can be measured with an oscilloscope technique if that is all you have. It certainly can quickly be estimated by an L-R time constant measurement. Otherwise, I would put one of the resistors on an impedance bridge and measure it. Then find out what the total would be when I hook them all together and then finally add some series inductance for any wires that are needed to attach to the load. There are standard formulas for calculating.

But if you have access to an LCR meter or equivalent, nothing is better than a direct measurment.

 

[em2006]

...
It is just an IGBT with a resistor on the anode connected on the positive of the supply voltage.
...

May be collector, not anode.
(igbt.png).

 

[jrz126]

Cant you just put a free wheel diode across the IGBT? (cathode of the diode goes to the emitter and anode goes to collector).

 

[Roff]

Cant you just put a free wheel diode across the IGBT? (cathode of the diode goes to the emitter and anode goes to collector).

The diode needs to go across the (inductive) resistor. A diode across the switching device only helps when the collector tries to go negative, which is rarely the case with an inductive load.