yogece
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short answer = yes, as long as the load can handle the current, and the IGBT, and the source ...
100% duty cycle mean IGBT is turned on for long time... can't speak about a switching converter anymore.
Many application limit duty cycle to 95-96% because need some time for turn-off... so can't go above this limit, but can have "100%", aka IGBT turn-on for long time.
Hi,
Every IGBT can work with 100% duty cycle.
It's not a problem of the IGBT, it's a problem of the gate driver circuit.
And only high side and only if a bootstrap supply circuit us used.
As long as you connect the proper drive voltage to gate-emitter the IGBT will be ON.
Klaus
Hi,
I wonder why you use that expensive driver circuit.
It is designed for
* high side switching
* high speed switching
* power supply
* and a lot of other features that you don't need (at least according the informations you gave until now)
Driving an IGBT in 100% is fairly simple. It just needs a short pulse of some current to switch the IGBT ON, then about no current is needed for the rest of the time. No isolated supply, no precise voltage, no high current, nothing special.
Any BJT or dedicated low side gate driver FAN3100 (below 1 $ at Farnell) should do.
But we don't have detailed informations about your requirements...
You surely know that 100% duty cycle means "DC operation condition", no frequency, no switching.
But you have chosen an IGBT that is meant for high speed switching applications, so don't be surprised when the datasheet focusses on this.
It's a bit like this:
You want to use a plow, you know it needs a high power engine to operate it. Now you see that a Ferrari has a lot of power.
But the Ferrari's operating manual does not mention about a plow.
I'm not sure whether the IGBT or the driving circuit is suitable for your application. But if you don't want switching, just ignore all the "switching" specifications in the datasheet
Btw: If a device (not important whether it is an IGBT, BJT, MOSFET or any other device) is not able to operate at 100% duty cycle, then this needs to be mentioned in it's datasheet. I can't remember ever have seen an IGBT specification that says that it is not able to be operated at 100% duty cycle.
Klaus
You surely know that 100% duty cycle means "DC operation condition", no frequency, no switching.
Right.
If you want a 100% duty cycle, why do you need a switch at all? It is not going to be turned off, right?
But how a chopper is going to work with a 100% duty cycle? MY knowledge is rusted, but I think choppers would love to live with 50% duty cycle.
Duty cycle is defined for a pulse train for which ton and toff can be variable. But if either ton OR toff is zero, the pulse train ceases to be a pulse train.
My understanding is that the duty cycle cannot be 0% or 100% - because in these two extreme cases the pulse train ceases to be a pulse train.
On the other hand, IGBT is essentially being used as a switch and duty cycle is not a meaningful specification for a switch.
Or am I missing something?
I'm not surprised.i have asked the manufacturer for some application note/guide lines for using an IGBT module duty cycle above 95% but they don't have any reference for these kind of applications.
That gate driver: the Semikron SKYPER 32R can be run at 100% on time for the upper IGBT, we have made many hysteretic controllers for 50kVA power stages where the upper devices ( and lower and middle devices ) are on for several mS to get a certain current slew (e.g. -100A to + 100A ) on 3 phase mains - so take many of the above comments with a grain of salt ( i.e. just ignore them ).
Our controllers have an average sw freq of 15kHz, but range from effectively DC ( 100% on ) to 30kHz max
If your control design requires long ON times the Semikron SKYPER 32R will be able to do it ...
This is what i expect from the community; some one might have worked with DC choppers,DC SSR,DC circuit breaker,DC load Switch it would be helpful if they could shed some knowledge about the DC operation of IGBT and its thermal details
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