Resolver Excitation with V2 mainboard

[arber333]

I have to write my observation before I forget.
Last time when I tested two leaf motors with Ampera inverter I noticed some consistent behavior.

1. Boost dependence. When I used low boost I got low rpm, when I used higher boost I jumped to higher rpm. By low boost I mean 4000 VS 12000 setting. I didnt get to see what happens at 15000 boost yet.

2. Offset behavior. When I found offset where motor would move at first I got 800rpm no matter what my frequency was. That was at 30kpt. At 34kpt I got some 4krpm from motor. While at 38kpt I got 8krpm. It seems there is a constant for this 1krpm improvement for 1kpt offset. However with 39kpt I got to 9krpm but motor was turning rough and immediately tripped OClimit.

I happened to had a moment when in my head I actually saw the field moving back and forth when I changed offset. Johannes what I am saying I saw the result and it was 8krpm regardless of voltage. So some weakening happened there. I think software would have to vary the offset when voltage comes to fweak. That way rpm would extend beyond voltage range but torque would have to be limited somehow. Would that be amplimit? Hm. Is there a way to encode varying offset in the correct direction. Like setting the sweetspot offset and after that setting a range to extent offset the way it would increase rpm.
Maybe it would be good to just set PMSM motor in parameters to avoid confusion.

[arber333]

Well today i had ups and downs.
First last time on idle my Leaf motor obviously broke one side of Volt inverter!? I had to connect the other side for testing to continue.
Well once i had boards working again i put them in the car. First i checked direction of rotation. Of course it was reverse.... so this time i didnt switch phase cables. I just added/substracted 16000 to offset and i got it turning in the correct way. BUT i noticed motor was running rougher than before. I had to make some corrections and we got in a car and went for a RIDE!!!!

It was a slow ride. I had to correct offset to get a good driveoff and eventually it went without OClimit. In 2nd gear i have seen on my phone amp draw of some 50A from battery and spikes of 300A+ of phase amps. Max rpm was some 4200rpm at 400Hz setting. We tried uphill and downhill.
There was very uncomfortable surge after 30Hz when car was comming to a stop. Regen was also uncontrolable. It just happened without conforming to some pot or setting. That would be something to work on. I guess inverter should provide some excitation for regen to lessen direct force on magnets. Now it looks like its connected to diode bridge directly.

After inverter came to 65°C we returned home. No worries, we stopped and experimented some to lighten the roughness of the motor. Then I heared some noise like motor would be turning on idle very slowly like 1Hz throttle was at 0 travel so i stopped inverter. We went to inspect and didnt find nothing. Next time i tried to start inverter threw off DCcontactor right away. It let the precharge happen and after we would triger DCswitch it signaled Fault! NOT AGAIN!
I have inverter on my worktable now and it seems like Fault trigger transistor on Volt driver board is burned. It is a small SMD thing even smaller than SOT23 parts. I think it is SSMini3 package. I will try to replace both of them and then see what happens.

How would you expect they are polarized? Signal is grounded all the time inverter is in operation except when fault happens, then signal floats. Would that be NPN transistor properties?

Also Johannes would it be possible to have a button on web interface with next revision? That would save the graph frame and store it as a pic. I tried to capture frames with my phone and couldnt. I could capture interesting drive/regen data...

[doobedoobedo]

Can you get a magnifier on the package and see what's etched on there? Same size as SC-70/SOT363? Google might help with package and markings.

SC70 (below) sot23 (above) resistors are 0603

[arber333]

Hm... i found one burned Ampera driver board and changed transistors from fault position. Seems they are working. I get good fault response when i connect 60Vdc to inverter.
However when i connected mainboard there was still desat error. I inspected the main board and it seems that desat pin is allways pulled to GND. I saw on my interface board that i cnnected both desat and UVLO pins together. But now UVLO pin is pulling them both to GND. Johannes how is UVLO connected? Why would it draw it to GND?

EDIT: It seems my Olimex board developed UVLO pin towards GND. When i replaced it with another 2nd power stage works with 50Vdc battery. I still have to try it with 380Vdc.
1st power stage is relentlessly tripping desat no matter what i do. It seems it is damaged. I even tested without power stage connected and desat didnt trip then obviously.

[arber333]

To anyone who is interested...
I got 10 resolver interface boards from china . I will use 2 for my inverters. If someone is interested in bare board price would be 6€ with 5€ shipping inside EU. Outside EU i will let you know in PM.

I have started to populate one board. When i test it i can also make them populated. That will bite a bit more. I expect somewhere cca 15€ final price + whatever shipping. If you are interested PM me your adress and how many boards you are interested in.

[D@F]

Pm

[arber333]

Hi Johannes

Is it possible to use resolver interface with ACIM motor yet? I mean reading rotor position not the actual change from sine to FOC.
I have a setup with ACIM motor and RLS magnet resolver board. Should be interesting...

tnx

[johu]

No, resolver always implies synchronous motor, currently.

[arber333]

No, resolver always implies synchronous motor, currently.

Too bad... any chance you can port resolver into sine also?

tnx

[johu]

Could make the sine version always asynchronous and FOC version always synchronous

[ChazFisher]

I'm having trouble getting the resolver excitation working on my adapted Rev 2 board. I'm running Rev 4.87R-foc software, the encoder mode is set to Resolver, but I'm not getting any pulses at PD2, so obviously no excitation signal out. However, I don't have any other external I/O connected yet. Are there any error codes that would prevent properly initializing or starting the PD2 output?

BTW - I'd be very interested in having the resolver available for an ACIM as well. I'm planning to run a GM e-Assist motor/generator as an e-motorcycle motor, and it uses a resolver as its position sensor.

[johu]

It will only become active once you enter run mode. Sine firmware supports resolver as well

[ChazFisher]

It will only become active once you enter run mode. Sine firmware supports resolver as well

Thanks, Johannes. I found an error in my board layout that is holding the overcurrent limit fault. Am I correct that this will prevent entering run mode?

Edit: Yes, adding a jumper in place of the missing track cleared the fault, and allowed me to put the board into Run. Moving on!