RE: PSPICE IGBT modeling

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Leigh Copp" <Leigh.Copp@xxxxxxxxxxx>

I started with Microsim 6.0 for simulating IGBT inverters around 1995,
when models did not exist for large IGBT's. Microsim, which has since
been acquired by Orcad, which in turn has been since acquired by
Cadence, now has models for pretty much everybody's bricks.

At that time I started to develop my own model, which was based on a lot
of research through the IEEE Transactions on Electron Devices, and Power
Electronics. Powerex themselves had an experimental macro-model that
they faxed me that when tweaked, yielded some fairly accurate results
for the CM1000-28H devices I was using.

You are right; a controlled switch is frequently more than accurate
enough for power electronics simulations. Where I ran into trouble was
with higher switching frequencies of larger devices where the tail
current and turn on overshoot could be very detrimental. The Miller
effect was also of great interest to me, as the published data on gate
drive resistance was not valid for the larger devices at higher
switching frequencies.

PC's are comparatively cheap these days, so the penalty for model
complexity is less of a problem today than it was when 64 MB of RAM was
something to brag about. The larger problem is usually getting SPICE to
converge; the newer versions today allow you to select a solver model
(similar to the ".method" statements when it was still text based). I
think the student version is pretty crippled in this regard however.

I just checked the Cadence site and the 15.7 release is available for
download. If you have been getting away with the student version so far,
this might be the answer. I'm not sure which models they include, but
the site claims only complexity is limited.

Kurt: Which devices are you trying to simulate?

Cheers,

Leigh


-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: April 1, 2007 9:49 PM
To: tesla@xxxxxxxxxx
Subject: Re: PSPICE IGBT modeling

Original poster: "Kurt Schraner" <k.schraner@xxxxxxxxxxx>

Hi Steve,

thank you. There is perhaps not much need to model detailed
parameters of the IGBT itself, while the on- and off switching
transients and the switching loss I^2*t shure are of some interest.
But most of the time, a controlled switch of the kind you name, is
probably enough. Currently I'm doing simulations for different
induction coil "breaks", continuing the development similar to the
"Andiruptor", but now oriented toward a capacitor discharge system.

Cheers, Kurt

Tesla list wrote:
>Original poster: "Steve Ward" <steve.ward@xxxxxxxxx>
>
>Kurt,
>
>I typically just model them as "voltage controlled switches" with a
>diode across them as needed.  What parameters of the IGBT did you
>really need to model?
>
>Steve
>
>On 3/30/07, Tesla list <tesla@xxxxxxxxxx> wrote:
>>Original poster: "Kurt Schraner" <k.schraner@xxxxxxxxxxx>
>>
>>Hi,
>>
>>can I get an idea, how to model the IGBT (-bricks) in PSPICE, from
>>one of you solid-state coil experts?
>>
>>I'm currently using Microsim 8 (student version), and if I have to
>>speculate about the power circuit of an idea, I'm mostly building up
>>the simulation, based on timed switches. Anybody can help me to find
>>a better, less cumbersome and more realistic way to do that? Are you
>>introducing published Spice models of IGBT's in local PSPICE
>>libraries? Using other programs? Buying the unlimited ORCAD... etc.?
>>
>>Thanks for giving me some practical tipps, how to deal with the
>>problem. Cheers,
>>          Kurt