Hi all -
I joined and tried searching through the old posts, but could find anything particular to what I want to do. I would like to use vESC to control a BLDC motor for low speed operation for a piece of machinery with a pot/rheostat and possibly later with an Arduino via PWN/PPM for more granular control.
The current motor is a AC/DC Universal motor, 1.2Amps, 1/15hp. Its like 150Watts computed electric power. Think sewing machine motor.
Compared to a conventional brushless motor controller, the vESC has more features and controls. I understand that using this for my application, its to be considered 'experimental'.
Here is an example of the motor I am considering. BLWR233 and the associated controller, MDC100-050101. I would be using this with a fixed, mains power swiching power supply.
The wiring seems straight forward. wiring diagram below.
My specific questions are -
1. Can I expect reliable motor control at low speeds?
2. When you release the 'go pedal' what happens? If you are not using a battery pack, how do you bleed off the current?
Thanks in advance
sinneD
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I don't think you searched particularly well, that is a very common request.
VESC controlled via pot/variable resistor is done with the ADC control scheme.
You can use PPM to control the VESC but if you're going to be generating the PPM signal from an Arduino you will have more options if you use the UART control mode.
The VESC is a little over powered for a 150W motor, it's designed for ~1500W motors really.
By using a fixed mains supply you won't be able to take advantage of any regenative braking as this will probably cause your power supply to shut down. Check the specs of your power supply to see if current can be driven into it or search these forums for how to run a VESC from a mains power supply.
That motor looks to be very expensive/nice and has built in hall effect sensors so these should be connected and the motor run in sensored mode for low speed control/torque.
As you're running this from a mains power supply it will slowly decelerate based on the load, as you can't do regenative braking there will be no active braking but I believe that it will try to actively hold a stopped position just weakly.
I am having a terrible time searching for topics. I have resorted to going through the forum posts page by page.
Right now I am trying to learn about the number of poles and how they relate to the motor's lower speed behavior. I find lots of solved issues for things like throttle response and programming parameters and current control, but not much on the considerations of number of pole pairs with respect to the performance of the motor over its RPM range.
Can anyone point me to where I might learn about these motor and how they behave ? Manufacturer web pages are mostly marketing hype.
The motor you've listed is a 4500kv motor, you've not mentioned what VESC you're looking at but:
Old style v4.12 VESCs are limited to about 60,000ERPM
newer VESCs are usually around 120,000 or 160,000 ERPM
It doesn't say how many magnetic pole pairs the motor is but usually it's around 14 poles, so 7 pole pairs. This means you want to keep below:
60000 ERPM / 7 pole pairs = 8571.5 RPM
120000 ERPM / 7 pole pairs = 17142.9 RPM
Going above these won't necessarily damage your motor but it will not be smooth, VESC allows you to limit the RPM to avoid this.
Poles doesn't have a massive effect and if you use the hall effects they'll allow the VESC to control the motor down to 0RPM quite well. That's probably why you're not finding many threads.