Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[ChiefsBuggy]

Paul,

My breadboard runs your code into a transistor network into my scope to prove the logic. I'm still not able to convince myself the flux angle position logic is right at speed. Also, the low RPM torque logic doesn't seem to be there.

I'm not driving a motor yet as I haven't built up a high-current IGBT driver yet.

The second project I'm working for you is getting a decent supply out of the isolation transformers. It looks like we need a feedback loop to maintain a consistent voltage over load. The 4011 has more processing power to do with, but I'd need to write a feedback control to do with (probably with a software PWM as we are out of PWM slots).

So, still working on it.

Good design! Its evolving in my head right now, but you have made incredible progress so far.

AN908 is a great seed, but its time to make it produce fruit! ;-)

Jim

PS: Jack's right.... You Da Man!

[MPaulHolmes]

The rotor flux angle code in the stuff that I sent isn't for a standard AC motor, but for a permanent magnet synchronous motor. Well, it didn't work on a quick test I did on a borrowed PMSM motor, hahaha, but that's what it's supposed to be for. For the PMSM motor, the rotor flux angle is exactly the same as the rotor position (plus some offset that you have to figure out), so Id, the magnetizing current is 0, since you get the magnetic field for free. I haven't tried to do the AC version, which has a few more messy formulas for indirectly computing the rotor flux angle.

[jackbauer]

Damn my goldfish like attention span..........

........5 seconds later...

.....hey what's this? an AC controller?? You Da Man!!

[MPaulHolmes]

haha, I bet those schools of fish sure don't learn much. Now, johnny, don't eat hooks. 5 seconds pass... Johnny! No!!!

[energymiser]

Hay there. I haven't seen any activity on this forum in a couple of weeks. Any progress?
I know life can get in the way of these projects. All the best.
Nigel.

[Simy]

Hello everybody,

I'd like to start building the control board if its design is static so far, or is it likely to change? I really want to get started tinkering, not sure how much help I can be but I've got solder and a soldering iron. =) I'm so so with code but I can sometimes program things.

I plan on getting or making/adapting a cheap 3 phase motor (preferably a small one) to test with and get it to work in FOC mode. I also will need something to drive the motor when I go shopping for one. =)

I plan on slowly saving up/building/making parts that I will need to most likely convert a small sedan. Its going to take me awhile though. My commute is only 12mi round trip so batteries with lithium should only be about $1-2k to be able to make it to and from work. Since the controller is one of the most expensive parts I plan on attacking that first. I figure I can shop for some IGBT's on ebay, or just wait until I can find a good deal. I'm impatient but my budget wont let me rush things

So if the control section isnt going to change could I get a parts list and or PCB layout =) I'll be your best friend.

Also is the control board specific to IGBT, or is it the same control board (plus or minus a computer of things) with mosfets?

Keep up the great work, about 2-3 years ago I was going to make a controller but kept getting bogged down with other responsibilities. This time though I've got a reasonable budget (half a shoe string is reasonable right?) and time to see it through.... If things don't change...

[MPaulHolmes]

Hello! The control board works, but needs a few changes made, and can be done cheaper. Also, the software needs testing and debugging. The code is 99% right, so it's more inadvertent bugs than anything else. I need to get a new AC board made. grr! It wouldnt' take too long, and I have the 3 dual igbts for testing.

[Simy]

Thanks for the quick reply.

When you determine the control board to be static I'd be happy to help debug the software. Like I said I'm not that good so it may take me longer then somebody who knows what they are doing but I may still be able to make some progress on that front.

About how much is the control board in parts? Its in the $300-$500 range isn't it?

[MPaulHolmes]

Oh heavens to betsy no. The new control board will be MUCH less than that. Less than $100.

[Simy]

Got a parts list yet then =) Do I need to buy a gizmo to program the pic?