AP30G120ASW equivalent for UPS repair

[tomizett]

Hi All,
This is a long shot, but I wondered if anyone had any advice to offer on this.
I have a UPS (uninterruptible power supply) to repair and, as part of this repair, I need to replace the inverter IGBTs at the output. The inverter is a true sinewave type using a high-frequency half bridge, pulse-width modulated (it is not a modified sinewave type with a low frequency iron cored transformer).

The original parts are AP30G120ASW from Advanced Power Electronics, see
https://pdf1.alldatasheet.com/datasheet-pdf/view/509369/A-POWER/AP30G120ASW.html
however these are unavailable in the UK, so I'm trying to find a replacement.

I've searched through some datasheets, but notice that a lot of the devices of the same current/voltage specifications are described as "optimised for soft switching applications" and are substantially slower/have higher gate charge. This is my main concern, as the switching frequency and dead time are unknown to me.

My questions are:

1. Does anyone know where in the UK I might be able to source this transistor (AP30G120ASW) directly?

2. Can anyone recommend a drop-in replacement for this device in an inverter application?

3. Does anyone have general advice on selecting a replacement? Are there any pitfalls I should be wary of?


Our records show that I've previously repaired a similar UPS (an older model from the same manufacturer) using the HGTG18N120BND, although I'm not sure (my notes don't say) if that was the original device or a substitution. See datasheet here:
https://pdf1.alldatasheet.com/datasheet-pdf/view/52765/FAIRCHILD/HGTG18N120BN.html

4. Does anyone have any comments on the suitability of the HGTG18N120BND as a direct replacement for the AP30G120ASW?

Thanks in advance,
Tom.

 

[tomizett]

Just for the record, I'll update this thread by saying that I ened up fitting the HGTG18N120BND. It performed happily under test and the equipment is now back in service. I'll update you if it breaks down again...

For the sake of completeness (in case anyone else comes up against the same problem) the equipment in question was a Borri B400 UPS, and the root cause of the fault seems to have been the 470pF snubber caps on the inverter stage. One of these was short (tens of Ohms) and the other open (or at least very low value).