This could almost be a first in that I don't often ask questions. Some of you might remember my mention of a Patent what I have applied for. If you don't then an explanation about it is here.
I'm going to be putting up another page with a refined PFC circuit using a modified method to achieve the same result later on.... soon. This one will show a full model of a 2kW PFC circuit operating off a 90V line at 100KHz with an IGBT with main power semiconductor losses in the order of 60W.
That's 97% efficiency..... It might get better than that if I used an SiC diode but, at the moment, I'm implementing resonant turn off of the diode and that's costing me 20W...... I wouldn't go so far as to say I'll get the losses down to 40W as a result because I'll suffer switching losses elsewhere.... and, of course this is just modelling.
Anyway, as I mention on the first page, I'm bothered about the Veb rating of the transistor in the IGBT. I've had a 'touch' from a semiconductor manufacturer and this problem has been mentioned. The concern is the figure itself and possible reliability issues when driving the device as I have suggested, they have no long term figures for this kind of operation.......
There are other 'issues' but for the moment this is the one I am looking into. I suppose I should just accept that that is the problem. These people have more experience than I do and therefore it is a non-starter...... However I do know that power switching transistors are operated in this way, although there was some mention of differences in manufacturing in particular passivation, with Veb being applied to achieve fast turn off.
Anyway, I'm off for a trog about the web to see if I can find any information relating to reverse bias operation of IGBTs giving limits and reliability information. I'm afraid my natural assumption is this is either a wool pulling excercise or the person I am dealing with might be mumbling because they are not absolutely certain themselves.
Specifically I'm looking for ratings and limits for transient rather than DC operation. If anyone has thoughts on this or can point me in the direction of something to read then I'd appreciate it.
Obviously, for those who care or Don Lancaster, I'm not losing sleep or money over this. Just time and my time is free.
Thanks
DNA