Can the Simscape DC Motor block be used to represent a BLDC motor?

I am currently trying to estimate the maximum speed and acceleration of a small electric 4-wheeled vehicle, along with the BLDC motor's current draw, rpm, torque, and thermal characteristics. I am not concerned with speed/position control at the moment.

I have assumed that I can use use the BLDC spec sheet's phase resistance, phase inductance and torque constant in the "armature resistance", "armature inductance", and "torque constant" fields in the DC motor block. Is this a fine way of doing ballpark estimations? Are there any subtleties I should be taking into account here?

Answer 1

[Divyajyoti Nayak]

Hi @Michael P,

BLDC motors are just a more efficient DC motor because of their brushless design.

The use cases and physics should be the same for both, hence your method of filling the respective properties of the “DC Motor” block from the spec sheet of the BLDC Motor should give you accurate results on simulation.

Here’s the documentation for the different parameters of the Simscape “DC Motor” block:

https://www.mathworks.com/help/sps/ref/dcmotor.html#brebfy9-5

[Michael P]

Thanks for your help. I'm wondering if I need to multiply the resistance, inductance, or any other parameters by some constant when using the DC Motor block to simulate a BLDC motor. My intuition is that the "phase-to-phase" resistance (as usually reported in BLDC spec sheets) can be directly used, since this would automatically give an equivalent resistance for a DC motor -- but I'd like to be sure. Does it matter whether the BLDC uses delta or wye winding?