Quote:
Originally Posted by MPaulHolmes
I have one major problem. The AC motor that actually has an encoder is only good up to like 1 amp per phase. haha. I feel fairly sure that it won't be sufficient resolution to test the FOC code on that motor.
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You are right, 1A is very low current, resolution will be very low. What chip are you using for hall effect current measurement ?
Quote:
Originally Posted by MPaulHolmes
The big fat motor can handle higher amps, but the motor post is too big for the encoder from the company that I've ordered from before. So, if anyone knows of a good "encoder" company I'd be happy to hear about it, yo!
Yes, I'll post all the schematics once I see that it doesn't blow up under load. haha.
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If your first goal is to test the controller hardware with high output current, think you can easy test it on your big motor without encoder, just using your FOC algorithm in open loop mode ? In my case, I do this by simulating a rotating rotor position at the speed I want instead of real motor position. The result is a rotating field on stator with the speed I want and with the current value I want depending on my current consign. It permits to send a lot of current without load on the motor, thus testing the full current capacity of the controller without a brake on the motor.
I think you can do the same by simulating the output speed value of a virtual encoder ?
Quote:
Originally Posted by MPaulHolmes
And yes, that other controller was a commercial design, but was very clean, using an intelligent power module from Powerex I think.
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For the PMAC 700V/200A controller I will maybe have to develop in next month, I will probably use powerex products. They have very good thing at very competitive price !! As an example, a dual IGBT module in 1200V/300A configuration costs 135$ :
Darrah Electric
They also propose the corresponding isolated driver board for 14$ :
VLA503-01 Powerex Inc | 835-1065-ND | DigiKey
and the isolated supply for 14.7$ :
http://www.digikey.com/scripts/DkSea...-15242&cur=USD
Thus total cost become 3x150$ + 6x14$ + 6x14.7$ = 622$.
"Just need" to develop the 3 small board to connect 2 drivers module and 2 corresponding isolated supplies, the control board, and the DC bus capacitors filtering board.
Really interesting I think to quickly develop a 700V/200A AC controller when very low price is not the first consideration !!
