[MPaulHolmes]

It's always fun to read all these updates when I've been away! Here's my understanding for the losses with the IGBTs. There are switching losses, and conduction losses. The DC controller switches at like 7-12kHz (spread spectrum) so it averages maybe 9.5KHz or something like that. Each time the IGBT turns on and off, that's one of the 9500 per second. So, if the turn-on energy is 50mJ (for example) and the turnoff is 50mJ, then the off/on cycle is 0.1Joule, or 0.1Joule/cycle * 9500cycle/sec = 950 watts. JUST FROM TURNING IT OFF AND ON!!! AAHH!! But notice that their numbers for switching energy are at the absolute worst case. Like 600v and 300amp or whatever. If the current or voltage is less, the switching energy falls dramatically. Sometimes they don't include the full range of switching energy vs current, but sometimes they do.

Then there's the conduction losses, like 1.75v while on. Then if you are at, say, 50% PWM, then it would be current * 1.75v * 0.50 for the waste heat from conduction losses.