2M150F-050 for Mazak CNC Laser

[Sterno]

Hi, long-time lurker, first time poster and I'm hunting MOSFETs.

I've been looking for a couple of days now for some 2M150F-050 MOSFET power modules, originally made by Fuji and all I've been able to do is place a couple of inquiries on Alibaba and Chipfind. 

Google has not been my friend and it appears these parts may be obsolete/discontinued.  This is bad news as we have a CNC laser that uses 12 of these for laser power regulation and we've determined that 1 bank (4 Modules) is cooked.

Anyone by chance have an idea for sources to check?  The boss is, of course, in a rush and we need them ASAP as production has come to a near standstill in our Fab shop.

Thanks in advance
Steve

[tautech]

Some time back I tried finding some datasheets for similar and it seems they are out of production.
Found the datasheet for these though. Attached.
Fuji N Ch, 500 V 50 A dual power mosfet module.

First thought was a Semikron equivalent, alas nothing like it.

Are you prepared to mod the circuit to IGBT's as they seem more often used in high power work these days?

http://www.semikron.com/products/product-classes/igbt-modules.html#view/table/items/100/

[Sterno]

I should mention that I'm not an Electronics professsional (yet)  I do simple industrial controls (VFDs, PLCs, pneumatics) as a second job. 
I have had some electronic training and worked as a consumer electronics service tech in a previous life so I'm not unfamiliar with troubleshooting.  I have however done little circuit design and have never even held an IGBT, never mind designing for it.

I doubt I have the required skills to mod the circuit in the way you describe but I am looking into replacing these units with discrete MOSFETs and am furiously reading datasheets all weekend.

[tautech]

A Google search: "substituting Mosfet with IGBT" or similar, maybe with the addition of "power" will give you plenty to study and I believe IGBT's are a viable option.
Recent documentation confirms that a substitution is entirely possible.
Careful matching of specs is required.
Surely the likes of Semikron have a technical adviser that might help?
However if I understand the OP correctly, there are 3 banks of 4 devices and to replace only 1 bank with a different device may not be possible.

If as you say they are for laser power control, presumably all banks are used together?
Or a bank for each phase?

[Sterno]

You are correct, tautech.  there are a total of 12 devices in the machine, three banks of 4, each bank with it's own power supply, control circuitry and output transformer. 

But,  I'VE MADE A HUGE MISTAKE!
I went and posted those requests on Alibaba using my regular email and the result has been spamtastic.  94 replies in the past 18 hours,  all of them claiming to have the (discontinued) device in stock.   
I'm going to gamble and choose one of the vendors that seem legit and claim quick shipping.  I'll order 4 MOSFETs and hope something useable arrives in the promised 5 or so days.  Worst case scenario, I'll be out $100.

In the meantime I'll follow your advice and study up on how to implement IGBTs in place of MOSFETs, no time like the present to learn!

[Sterno]

Quick update:
The MOSFETs arrived from Hong Kong.  9 days instead of 3, no real surprise there.  They look and perform just like the originals, including the Fuji label.  They're either genuine or a really accurate copy.

Now that they're in and I can start the HV supplies back up I get to hunt down the power imbalance that likely cooked the FETs  in the first place.  Lots of measuring and comparing between the 3 banks.
I'd be willing to part with significant pieces of my anatomy for a schematic but no such luck, Mazak guards diagrams with an iron fist.