Hello everyone, Im an Energy Engineering student, currently working on my prototype for my thesis. The goal is to build an efficient electric vehicle. After some research, I came to find out that FOC is the most efficient motor controller. Since my program is not focused on electronics I have less knowledge on creating such projects. Can anyone help me build (step-by-step) FOC for my BLDC motor (48V 800W) without regen breaking. Battery specs: 48V 18AH. Sample schematic diagram will be helpful. Any help will be much appreciated. Thank you and Godbless!
In my experience, building an ESC from scratch is quite difficult. Even with an electronics engineering degree and 20 years of experience. So a “quick and dirty” schematic will contain small errors you’ll have to find and correct for yourself and that’s not trivial.
Suggestion 1: Buy a VESC (or clone).
Suggestion 2: Start with the VESC schematic and work from there.
(just to be explicit: 2 is the “probably too hard” option. )
Alright thank you so much! What do you recommend to use for more efficiency, BLDC or PMSM? and is it sensored or sensorless?
BLDC and PMSM are different names for the same thing. At larger powers and voltages, people tend to use PMSM more, except when in the RC world.
Sensorless is “tricky” if the motor is moving slowly. So if you’re rarely going slow, sensorless is fine. On VESC you can sometimes detect the “above XXX we switch to sensorless”. And you notice it running better sensorless. The controller then has a better “feel” for the motor.
But this doesn’t guarantee that simplefoc will behave the same.
ChatGPT declares that once a motor is built for sinusoidal excitation (=FOC), you’d call it PMSM.
Efficiency would be a factor of how the system will be used. 1 speed only, lots of high speed, lts of low speed, a balance of high and low speed.
You can then choose to have an internal or external rotor, surface magnets or internal permanent magnets. Often the sensors in the controller and motor also aid in efficiency.
Current sensing per phase, only 2 phases, only on the DC bus in?
Hall sensors, sin Cos sensing.
All these have an effect on efficiency,