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

[nlc]

I received PCBs and components today, then I will try to do a video about qfp soldering this weekend !

[CollinK]

Yes, it is certainly possible to solder 64 pin QFN chips with a normal iron. It's just that less people know how to do it.

I suppose my biggest reservation about the STM32 is sort of a nit picky thing: It really doesn't come with the source code to the FOC library. The hardware of this device is open source and I think that the software should be too. Microchip has freely available source code right on their website for FOC. I need to check into it more but I don't see it being a problem to use their code in an open source firmware.

The STM32 code also seems heavily geared toward PMSM drive. That having been said, it does appear that the library probably supports async ACIM too.

I guess I'm just leery of using a black box. The STM32 code is all packaged away and you are just supposed to trust that it works the way you want.

[nlc]

I agree with you, it's why I requested (and received) the entire code source of the ST FOC V3.0 library from ST (under NDA), because I cannot deliver a software to a customer without perfect knowing of all source code it contains. The library is well designed and well coded. They use object programming style, and all functionnality is very independent in its one source file + private header file + public header file. I gradually study all source file, and because all functionnality reside in his own "blackbox", and software is based on different layer, it reduce the bug probability.

From my opinion, after reflexion, for an open source project I am not sure it's really a problem to have the complex part of the code to be a library if it is proved to work correctly and is highly configurable (which is the case, it is extraordinarily configurable !!). Because FOC control is a complex part, and for example even if I understand the principle, I will take a very long time to write my own FOC code (I hate math !!), or even modify the source code provided.

I think they deliver the FOC code as library because it seems they have very recent and powerfull algorithm for sensorless FOC.

For your question, yes, the library seems to be able to drive ACIM motor too, but I have not read this application note for now !

[nlc]

As promised yesterday, the explanation of how solder a QFP package easily with normal soldering iron, normal solder, and without flux.
Sorry for my poor english ))))

Part 1 :

http://www.youtube.com/watch?v=8ILA_qEYr0g

Part 2 :

http://www.youtube.com/watch?v=YFNe2uh3z84

Part 3 :

http://www.youtube.com/watch?v=haRcLwW6-6Y

[lechancel]

bravo thank you for your tip
Régis

[CollinK]

Just a quick note: I'm working on putting together an AC controller based on preliminary schematics from this project and the source code that Paul had for the project. The source code is currently in a repository under SVN control and I'll post the link once it's operating properly. I'm using the VLA500 based boards that Paul and mrbigh had.

Hopefully I'll have good news in a week or two. I'll put up videos of the whole thing too.

[nlc]

Hello, from my side, I successully started the controller you seen in my qfp sodering video above. It use a stm32f103 and run the stm FOC library. I am really impressed by the smoothness of the motor rotation with FOC control, even at very very low speed. Habitually with brushless hub motor and associed made in china controller, there is a lot of electromagnetic noices and a lot of vibration, particularly at low speed.

Here a small video of my test, but in french

http://www.youtube.com/watch?v=onF92CjEX8w

Phase current consign is 20A, and the second motor on the test bench has its 3 phase shortcircuited, to have a big load on the first motor. On the scope you can see the current of one phase, it's a very clean sinusoidal current !!!

And there is no noice and no vibration, very impressive because with high torque and very low speed, below 50rpm !!

[CollinK]

Originally Posted by nlc

Hello, from my side, I successully started the controller you seen in my qfp sodering video above. It use a stm32f103 and run the stm FOC library. I am really impressed by the smoothness of the motor rotation with FOC control, even at very very low speed. Habitually with brushless hub motor and associed made in china controller, there is a lot of electromagnetic noices and a lot of vibration, particularly at low speed.

Here a small video of my test, but in french

Awesome stuff! I thought about using the STM32 stuff but obviously I've went back to using a dsPIC and starting with Paul's code. The reason for this is that I feel that it is better to teach people about motor controllers and their operation if the source code is out in the open. The microchip code is freely available on their site and soon our code will be too. If anyone is curious how V/Hz works or how field oriented control works then they can look at the relevant code and find out for themselves. They can tweak it and try again to see how it affects the results. The resulting code, at least at first, is likely to not be as good or full featured but it's (I think) more accessible.

Using the STM32 library is certainly a way faster and safer approach (that is, one is less likely to blow something up). I'd recommend it for people who want to make their own controllers with a minimum of fuss. STM32 chips are certainly very nice and one wouldn't go wrong in choosing that path. I'm just interested in the harder, more illustrative path.

Anyway, keep up the good work. It looks very nice so far.

[thadm]

Originally Posted by CollinK

Just a quick note: I'm working on putting together an AC controller based on preliminary schematics from this project and the source code that Paul had for the project. The source code is currently in a repository under SVN control and I'll post the link once it's operating properly. I'm using the VLA500 based boards that Paul and mrbigh had.

Hopefully I'll have good news in a week or two. I'll put up videos of the whole thing too.

Thank you, Collin for collecting and compiling the works up to this point. I had spent most of the weekend reading through the thread, and was a little disappointed that it looks like the thread has "gone cold". This seems like a very worthwhile project, and if the source is in a (mostly) stable state, I imagine that it won't take long for fixes and enhancements to start coming.

I consider myself to be a likely contributor to the code in the future. While I'm proficient in "C", for real-time, highly mathematical calculations I'm sure it may take a while to get up-to-speed on the project.

I'm thinking of adding support for 6 phases, as (it seems at least) many 3 phase motors can have extra leads added to increase the number of fields. Yes, the hardware will need to be modified, but components can have lower power factors as well. Just thinking out loud mostly here...

Thank you again. I look forward to seeing the project "all in one place".

[energymiser]

Hello Paul. I hope everything is okay with you. The last post I see from you was 17 July. You were testing/debugging/modifying. I know its a huge undertaking but it would be great to hear from you.

Nigel.