Just a few questions before I try an ODrive. Trying to reduce the horrible whine on my car’s custom blower motor, which happens mostly at low RPM:
sine wave commutation suffers from reduced power load compared to trapezoidal since the average current is lower. So I’d like to know how much will my RPM reduce compared to an ordinary ESC using trapezoidal commutation? I was thinking of 1st, calculating the coefficient of friction k using the ordinary ESC
airFrictionTorque = k * angularVelocity = motorTorque
then derate by a constant factor for sine. Does sine reduce the average current (hence torque) by some magic percent for all RPMs, or is it more complicated?
So far I’m assuming the sine has the same peak voltage as a trapezoid. So if the torque load is tiny, then the top RPM should be unaffected, just take longer to accelerate.
But then I saw this post:
It says the peak voltage is reduced to 87% of bus voltage? My power source is 12V, so that would be pretty bad.
The obvious solution is to get a higher KV motor. I also read about hybrid sine commutation for low RPMs and then switching to trapezoidal at high RPMs. Is that any good?