Hello Friends, Is it possible to deduce the maximum no load speed of a brushless dc motor by the back EMF constant Ke or Kv?
I found this article that describes how to find the maximum speed and tried following the steps:

https://things-in-motion.blogspot.com/2019/05/understanding-bldc-pmsm-electric-motors.html https://en.wikipedia.org/wiki/Motor_constants/

I have a motor with the maximum speed not mentioned in the specifications. A snap shot of the specifications are given below:

Here Ke is mentioned as 4.64 Vp/KRPM., converting it into the motor velocity constant (1000/4.64) , this comes to 216.4 RPM/V.
If the input supply voltage is 30 v (Vdc in the diagrm below), does this mean that the maximum speed the motor can theoretically operate is 30* 216.4 = 6492 RPM?
In some TI websites and application notes ,they mention that the input DC should be multiplied by 1/sqrt(3) first! (30/sqrt(3)) * 216.4 = 3750 RPM.




I am confused as to which is the correct equation?

The end goal here is to try and establish an equation that tells me the minimum Vdc value that is needed to run at rated speed.

 

Moderators , Request you to close or move this thread, I think i have posted in the wrong forum category.
I will post again in the general electronics category.

 

MOD NOTE: Closed at TS's request. Please visit the TS's new thread.