I think you must be mistaken then. Just because the motor is hotter doesn’t mean it’s less effecient.
If the test conditions were actually the same, and both tests provided the same amount of braking power, and FOC generated more mAh, then FOC would be more effecient, completely regardless of the motor heat. The losses would be in your battery heat, vesc heat, AND motor heat combined.
Think his comparison is of recharge amp hours and having ridden w foc needed more.
But why can’t we change frequency in bldc similar to how u can in foc?
There’s another thread here showing testing of foc efficiency being bad and the programming I think was suspected
Another problem with that comparison is that it been discovered recently that the energy computation of the vesc may be far off, and the switching frequency has a key hole in it
Since BLDC uses variable switching frequency, we can’t even do an external measurement and find a correction factor since it will be dependent on how you ride
The safest way to assume would be to charge to full and do a full discharge test, Same course, keeping the same speed by limiting in vesc tool and see which one you can go farther
There is next to none energy dissipation in the battery and VESC. At least they don’t get warm. I only base my idea of the FOC mode’s lower (overall) efficiency on the recharge figures. I can simply ride 15-20% longer on the exact same set-up in BLDC mode, and that makes a huge difference for me.
Yes, I am using charge testing. And range testing: I simply can’t make the same distance in FOC mode.
Clearly I’m missing something then, because your figures clearly show that you generated more recharge capacity on FOC, yet you’re saying you rode further on BLDC?
That would mean that either, you were riding faster on FOC and we’re braking at higher speeds, you were braking more frequently, or that you were braking harder and accelerating more.
And I’m not basing that on any technical knowledge of the vesc, I just know that what comes in goes out. Conservation of energy and all that.
is foc showing not as efficient? That’s rediculous no one found this yet if so. Is it improvable w different programming or something?
Will add that to my list of tests to do
You are misunderstanding. He means that is the amount he is charging the pack after a ride. I don’t think he is talking about the regenerative recharge of the pack during a ride.
That makes a million times more sense. Thank you!
Exactly. I have disabled regen until I have the dual direction tensioner system. The charging mentioned is after the ride.
EDIT: For posters below; My set-up is on a bicycle with dual disk brakes. I just posted here, because it seemed the only place with an active discussion on FOC vs BLDC.
Am I missing something? How do you brake?
Isn’t disabling regenerative braking the same as disabling brakes?
No when you disable regen braking you just disable the ablility to charge the battery when you brake. You are still able to brake
Then where do you put the energy?
Heat
10char
OH, its a bike! hhahahahhahahah.
Am I missing something? Its a bike. How is that relevant? For all we know bldc could be the better option on ebikes.
Well that’s bloody news to me. So I was missing something.
Even so is it still correct for electric skateboards then that when you disable regen that you can still brake and that the current is simply transferred to heat via the motors? Surely this would overheat our motors really fast.
Thats my understanding of regen yes. Disabled and more heat generated.