Hello,
I have a different, worse startup performance of my setup @ sub zero temperatures. HW - 412, FW - 3.39/3.40, sensorless BLDC mode. I have a specific low speed and very high torque application, I was able to tune parameters to achieve a more or less a robust startup and further rotation above 15C degrees or so, but @ 0C and lower the motor is unable to startup at all. The thing is that @ old FW218 and with the same settings the system performs much better.
What could it be?
Hi adamant
as we had quite a cold time here in Germany, my VESC 4.12 (FW 3.39) performed just as usual. Sure that your Batterysupply is behaving as it should. Some Li batteries does not allow subzero discharge AND a good BMC would cut of then. Just a guess. Most LiIon (LiMN+LiCr) batteries double their Ri from +10°C to 0°C, which adds to the lower Ri of the electronic+Motor. I'd advise to notice the current motor settings and have the wizard rerun on cold temp.
What did you set to change the low RPM/high torque? Normally only the current flow enables high torque.
Cheers
Sam
Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC
Hi sam.vanratt,
in my case it is not the battery issue because the same HW setup performs better @ FW 2.18. I would say that the startup performance is different @ the same motor settings if to compare FW 2.18 and FW 3.39. I don't know, maybe the FW 3.39 is much safer but it simply doesn't work in my case.
And yes, I was able to achieve high torque by increasing the max motor current setting.
Hi adamant
I (could only) guess that the VESCtool+according Firmware V3.x+ is more sensitive or does calculate the parameter differently. I hope you did the normal way when upgrading and then reset the parameter and have them detected as new and set your parameter again. If not the old parameter could have a different meaning. I've heard the most work was done in the FOC area.
As I am not able to read source code, maybe some other can help out, but open source normally (=in my understanding) means you are invited to dig into yourself and change to a "better" (=better fitting for your needs) code. Thanks to git, you could normally trace every revision and see what changed. The motor/driver parameter are surely on a single spot.
Cheers
Sam
Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC