FOC clarifications B-G431B-ESC1 ST board

Hi All,
This is my first post and requesting to please support me in clarifying my doubts regarding FOC and motor.
I am using the B-G431B-ESC1
evaluation board and Iam trying to run the hub motor using the code generated from the MC workbench provided by ST. I need support in the below clarifications

  1. The motor is 48V, but the board as per the user guide is a 24V and 40Amps. Now i am giving 24V 5 amps fixed power supply = 120W. I want to know if i can run the motor to some speed even under no load conditions.
  2. The Iq current I gave is 5 Amps, Id=0 Amps. Then does it mean i am providing 24*5 = 120 Watts to the motor? How to decide what value to be given?
  3. The ST gui settings shows SM-PMSM and I-PMSM. But the motor is BLDC motor, can i still run the motor?
    I have further few critical questions to understand and get confidence to run the motor. Please help. Please let me know if i have missed to share any information.


Welcome to the forum.

This is a forum for SimpleFOC, and we are not affiliated with ST Microelectronics. These question can be answered by ST Microelectronics engineers on their support forum at ST Community. Please kindly ask your question there.

If you run SimpleFOC on an Arduino platform on B-G431B-ESC1 then we could answer your questions.


Thank you for reply, is it possible to answer general questions related to motor and FOC, then probably I can correlate and get answers? I have lot of clarifications on motors and foc in general. The support at ST is very slow.

This board is for hobbyists, so feel free to ask, however, don’t be surprised if you get answers like “hit it with a hammer” or “use a bigger soldering iron”. It’s a free world.


Or, get Arduino and run SimpleFOC on your ST ESC board. Then you will get real answers.


Hey, that question is more complex - in principle you could see this 120W as a “rough” approximation. In practice, the motor is driven by 3 sine-waves, so the 24V is a peak to peak voltage, and the power drawn won’t just be the multiple of PSU voltage and Iq (it will be less).

Well, this depends on your application, right? Generally speaking, it is desirable to use the least power possible to achieve the goal (speed, time, load). The less power you use, the less heat you will generate and so the system can use smaller, cheaper components, last longer, etc…

I have never used it but I guess the ST software will offer different control modes? Maybe you have to tune it or set some parameters?

But basically to control the velocity, you need a velocity control mode - often this needs a sensor, but maybe the ST software can do it based on the boards current/voltage sensing?

A position control mode would allow you to set the motor position, like a servo.

A torque control mode would allow you to control the motor’s torque.

If you control only the voltage/current, then the motor will turn at whatever speed is natural for the given load (or it will stall if the current is not enough to move the motor).

I should think yes, but that’s probably a question best asked to ST-Micro.

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