I am testing a Predator 37/6 Motor on an Vesc 75/300 with a 28x14 propeller reaching 200 Phaseamps with a 16S Li ion battery without problems.
The motor is a 2kg sensorless Outrunner 170KV used for RC planes. I am using it in current control in beta fw from 27.06.2021
In detection it suggested 250A. In general the motor is capable of 15KW peak. So in theory I should reach more than 7KW as now.
Going on higher currents than 200A makes Absolut Overcurrent Faults at 50-60% duty cycle on 48-54000ERPM. ABS Overcurrent Max is set to 280A at the moment. 300A as value didn´t help and I don´t want to go much higher not to burn the Vesc.
When doing the detection I get different values for inductance of 1,07- 2,2uH. Other values stay the same, even when the motor is cold or warm.
A LCR Meter for better L values is on its way. As I read that measurement of L value on such motors might be not perfect with the Vesc.
I already tried:
-Detection several times
-500ms, 1000ms and 2000ms time constant for calculating Current KP and Current KI
-Switching frequency 60khz instead of 40khz
When the motor is running it does not get hot, max was about 55 degrees celsius.
I want to understand what exactly happens and what I can change to not go into ABS Overcurrent Faults.
So maybe someone can can explain the behaviour to me?
Here I have some bug triggered data and csv files:
https://drive.google.com/drive/folders/17kHEDRCybqKBftmRF6IV3MMOQv4LswKg?usp=sharing
I wanted to open the sampled data csv files, but when opening in Log Analysis tab I can´t see anything in Sampled data tab. Is there a trick?
Thanks for your help!
ABS means bad FOC settings most of the time.
Isn't measured inductance suspiciously too low? What about other measured parameters?
I would also reduce the frequency to about 5khz during the detection and test with those detected parameters.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
Thank you Vadicus, you were right!
Without reading your post I did some more testing and increased Inductance to 2,9uH. So now I can reach 260 Phaseamps over a long period without problems. But I also had to rise ABS Overcurrent Max to 350 A. I also tried 30KHZ,50KHZ and 60kHZ which didn’t work better. Values inbetween will be tested soon. Doubling Current KP or/and Current KI also didn’t help. V0 to V7 at 30KHZ made no difference.
I made some more sampled data pictures when ABS Overcurrent Fault occurs. They look all the same. Any idea?
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de
Also, try to reduce the gain. Changing flux value slightly (1-2 up or down) made a difference in my case.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
I got an LCR meter which was the solution for my abs_overcurrent faults. Inductance is now 3,92uH. I also doubled the Oberserver Gain. Now I am able to push 400 Phaseamps with a 13S battery at around 11KW. 400A Phaseamps are the limit of the default firmware. When changing to the NO HW LIMITS Firmware it did not use the 420A Phase I changed in Vesc-tool, which looks like a bug in beta fw from 27.06.2021. There is no other llimitation. I updated my data in the link of my first post.
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de
Olivier is very valuable information. What measurement frequency did you use when measuring inductance?
Witam :)
I measured at 100kHZ like Benjamin Vedder is doing in his YouTube videos :)
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de