Vesc MTPA

[Hummina Shadeeba]

Is this the extent of what u need to adjust to set up MTPA with Vesc?

 

[scianiac]

That is an old version of VESC, the current versions automatically calculate the Ld-Lq in motor setup so all you need to do is turn the MTPA on, of course how well it works depends on the motor as it only really works with a motor that has a fair bit of salience (Ld-Lq). However in those motors it is pretty impressive but more so for how much more torque you have at the mid and upper RPM range, I would still not plan to use it for long periods in field weakening above the base RPM.

 

[Hummina Shadeeba]

, I would still not plan to use it for long periods in field weakening above the base RPM.

Ok thanks there must be a button I’m missing

But what do you mean by what you said above? Don’t do it AND field weakening? It seems to have the same effect as field weakening anyway and I could just chose MTPA

 

[scianiac]

It is the same thing as field weakening and so for the same reasons heavily using field weakening to operate well above the base RPM for long periods has issues, poor efficiency leading to heat buildup, it's also not a great idea to do the same wit MTPA. This is probably a gross oversimplification in some regards and depends heavily on the motor but still in general better to gear a bike correctly from the start. Also I think currently the MTPA algo just uses the phase current limit so it will basically be like field weakening with the current set to the phase amps so a lot more than most normally use.

 

[Hummina Shadeeba]

In Vesc tool there’s the two options with numerical amount u can adjust. What’s a reasonable amount (positive or negative) and what are the differences of the two?

There’s a scary warning in Vesc tool saying be sure u know what ur doing or you’ll slam on brakes and blow up in a fireball.

I guess I’ll just have to see