I am a student of Electrical & Electronics Engg. I have been given "IGBT Tester" as my final year project at SIEMENS. I needed some information on how to exactly an IGBT is tested. It would be of great help if anyone could explain me the working of an "IGBT tester" preferably with a block diagram.
"raju" schreef in bericht news: firstname.lastname@example.org...
Depends on what you want to test. It could be as simple as a 9V battery, a pushbutton, two resistors and a led.
I would start looking at various datasheets, see what looks as the most interesting aspects of a IGBT, and then decide what needs to be tested/measured/verified and estimate what can be done in the time available for this project.
If you need inspiration, here's what seems a nice tester:
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Yeah, but let's be fair. These IGBTs are usually heavy duty, high current devices. A serious test is going to need a bit more current than a 9V battery can supply. OTOH, if the pulse duty cycle is very low, it might be possible. But the gate driving circuitry is probably going to need more than a 9V battery.
Jeez, 3000V at 2000 A (cough-cough!) Requires 230VAC at 16A! Just the shipping alone will cost a whole lotta money! Whew!
Like, here's a piece of equipment that takes more juice than the whole average home uses. Nice to plan ahead to make sure you can afford the electric bill. Remember those Startrek episodes where they had to make a choice between weapons and life support? Cap'n says Fire! and we hear the 'PLOINK!' in the background and all the lights go dim. COOL! Just testing another IGBT..
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Yes, an enjoyable scene to contemplate. But reality is a bit more prosaic for these devices: banks of electrolytic capacitors charged at leisure (230Vac at 16A is under 4kW - probably on the order of my home HVAC), then operate at the rated voltage and current (6MW) for a few milliseconds for the measurements. I made a 1.2kV 200A pulse generator (0.25MW, 5ms) in a 7" relay-rack box, and it was half empty. Although Lemsys' 6MW capability is 25x higher, it's not necessary for Raju to get into that territory. He could make something on the same size order as my box, big enough to test IGBTs up to TO-247 case size.
Just an added thought. One must pick an reasonable scale and then be satisfied with that. In the high-power engineering field someone, someplace is always making, or already has made something bigger.
For example, consider the impressive 6MW rating of the Lemsys tester mentioned above. Yet it's a real wimp, completely unable to handle the 400MW capability of a single Dynix PT85QWx45 5" SCR puck (4.5kV 90kA peak),
And if one were to design a tester capable handling the PT85QWx45, then how about testing an array of these beasts, say as required for a STATCOM (static reactive comnpensation) installation in a typical utility transmission line? Should such a tester be devised, it'd be completely unable to handle the serious testing requirements of DC high-voltage transmission-line converters. So on and so forth.
Hmm, perhaps Raju can satisfy himself with testing small IGBTs, say up to 600V 5A (130A max) parts; thaht's a more managable 80kW max. There's quite a selection of cute little so-8 guys with this rating intended for the huge flourescent ballast market, like Fairchild's FGS15N40L, see
Oh you've got it all wrong. These days nobody can know everything and it's more important to show you know where and how to get answers quickly than to re-invent the wheel.
When I was in the air cadets (20 years ago) we stayed on an airbase for a week. The staff decided to set us an exercise.... we had to make a map of the base, then pretend we were terrorists and mark on it where we would place 3 devices to best "take out the base". Not wishing to walk miles in the rain our team went to the guard house and asked for a map. The person on duty gave us a photocopy that showed just the outlines of the buildings and not what was in them... so we told him we were "terrorists" and he helped fill in the blanks and told us where to place our devices.... "Those three blocks are the hangers" he said "..but only that one has any aircraft in it". We were job done in 10 mins while the other groups got a soaking.
You could do some reading at IXYS website, look them up. They have PDF files on IGBTs' and MOSFET's and how to drive them, it could be useful to you.
A "curve tracer" has been traditionally used to test semiconductors in operation. they have selectable voltages and currents for the gate circuit and the power supply, I'm sure a curve tracer could drive a low powered IGBT with the proper gate voltage. They do a dynamic test where the gate is stepped with increasing voltage or current and the CRT display shows the response of the device under test. There have been projects and even kits at one time to build one of these. The simple ones uses an oscilloscope, ch1 and ch2 inputs are set to X-Y mode and the curve tracer plugs into them, then connect the component to test and set the dials. The master power dial is a power supply voltage control, usually up to 80 volts I've seen.
I've also seen a light dimmer modified with test leads brought out from the triac connections to test different triacs. This simple tester tests triacs in all polarities. A full dynamic test.