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

[MPaulHolmes]

The wiki is hopelessly out of date. Plus, 99% of the links are broken I think. hahaha. We need to get that bugger fixed up.

Janis, you absolutely could.

My new encoder came today, so now I'm going to start testing the FOC code with an actual encoder on an actual motor that can do lots of amps, not like the ghetto motor that could only handle up to like 1 amp! Hurray!

[e*clipse]

Good luck w/ the tests!

PM'd.

- E*clipse

[Janis]

High, How are You?
Two or three questions:
1) Have You thought of implementing of some kind of Autotune feature, like static/rotating autotune? Like measurement stator resistance (Viva La Resistance) measurement and motor inductance? A lot of problems, when not done with industrials drives, gigling and stiffing motor, if just connected. Rotatig autotune should help when not possible to uncouple the Load from motor. Or when uncoupled perform rotating Autotune which in addition measures load inertia (should be done when motor ucoupled from load). Yeah just go and learn load inertia?
2) Mr. FEEDBACK
Feedback is terrible and unsafe optic with just A positive and B positive eghes!!!
Please use also negative pulses, it's just for safety.
Have You imagined (when world goes crazy and you are attacked by Zombies) what happens when there is wire break on any A or B signal, (industrial drives just go crazy)with a lot of motor jigeling. I am voting for Mr. Resolver , stiff and rigid(like fallus(is it spelt right?)). Always can check resistance (Viva La Resistance) in any windings, and it is industry approved as most rigid and reliable closed loop feedback ever(resolver).
3)Do You take Mr. Bribes or just bribes?
4) People are strange when ure stranger

[Janis]

I never know, and that's exciting.

[MPaulHolmes]

LOL. Ya, a resolver would be the way to go with actual driving. But they are more expensive. I'm just using the encoder for testing. I take bribes. There will definitely be an autotune. For now I just blew up the test setup this morning using it as a stupid pure sine wave inverter for solar. haha. I have enough IGBTs for 4 more tries though.

[thingstodo]

A tune, static or dynamic, would be GREAT

The encoder is only for testing? So what is the 'permanent' feedback (or do you need any feedback)?

We don't use encoders, or resolvers. I'm told that they didn't hold up well in service - before my time. We use open loop vector control (vendors all consider their methods as proprietary - not a lot of info - something about measuring back-EMF from the motor)

[thingstodo]

Originally Posted by Janis

2) Mr. FEEDBACK
Feedback is terrible and unsafe optic with just A positive and B positive eghes!!!
Please use also negative pulses, it's just for safety.
Have You imagined (when world goes crazy and you are attacked by Zombies) what happens when there is wire break on any A or B signal, (industrial drives just go crazy)with a lot of motor jigeling.

With the digital signal processing available it's kinda scary that the industrial drives would not detect a loss of signal from the encoder.

[e*clipse]

While we're on the subject, I'd like to put in a request for resolver feedback capability. The 'Yota MGR I'm using uses a resolver for feedback.

Yes, it should be possible to monitor the signal to ensure proper encoder/resolver feedback. I'm messing with a magnetic rotational position sensor that puts out a PWM signal proportional to the angle. (for a throttle position sensor) If the signal flatlines either high or low, the controller knows there is a feedback error. Something similar should be relatively easy for both resolvers and encoders.

Sorry to hear about the solar experiment. What were you trying? It would be great to be able to use the EV for backup if the grid goes down. How do you plan on "throttling" the output to match the house demand?

[KUSAW]

Dear Paul,
how are you?
I want to order the PCB and the components...is it possible right now?
many thanks,
Kukuh Saworo
JAKARTA - INDONESIA

[TadhBijou]

Hello everybody and especially Paul.

How are you.

How are things going?