[frodus]

blew it? How so? because cost is $2500? He got a development kit, and had to pay full cost for parts.... you could cut that cost by 1/3-1/2 in bulk.

Its essentially 6 DC controllers (2 for each phase, one neg, one pos).... so its got 6 times the overhead on the microcontroller, 6 times the gate drive, 3 times the current control, 6 times the voltage sensing, vector or volts/hz control. 6 high power gate drivers, 3 IGBT dual packs....you get the idea). A DC controller is fairly easy to do, if you can get the FET's or IGBT's to gate at the same time. Its just pure PWM. An AC controller is PWM and PFM.

And not to mention, he can now use off the shelf AC motors, that don't have to be rewound, so that cuts cost quite a bit. Forklift motors are limited in voltage and RPM, induction motors can go quite a bit higher and are much more widely available. Just go look for an industrial 208V motor, they're everywhere.