I’m building a dynamic model of the Blue Robotics M200 BLDC motor, but I’m running into what look like inconsistencies in the documentation.
From the technical specifications, the motor has a Kv of 470 RPM/V and a listed stall torque of about 0.5 Nm. Using the standard relationship Kt=602πKv≈0.0203 Nm/AK_t = \frac{60}{2\pi K_v} \approx 0.0203\ \text{Nm/A}Kt=2πKv60≈0.0203 Nm/A,
this implies a stall torque of roughly 0.49 Nm at 24 A, which matches the specified maximum current at the nominal 16 V supply.
However, the published performance charts show a current draw of approximately 27.9 A at 16 V for a 1900 µs ESC PWM input. This exceeds the “maximum current” listed in the specifications by almost 4 A.
How should this be interpreted? Is the current shown in the performance charts the actual motor current draw, or does it refer to a broader system-level measurement (ESC + motor + prop)?
As detailed in the raw spreadsheet that has the data those plots are made with (linked on the product page, above the charts), the current listed is from ESC + Motor, driving a prop in a test tank.
This explains why my electrical dynamics was so hard to fit with the mechanical part and the performance sheets.
It might be great to have some data on the ESC and the Motor seperated to make propper digital twins for designing controllers, fault diagnosis and estimation methods?
Our R&D team is hard at work developing the next generation thruster motor - both collecting such data and modeling it computationally! It is quite an involved process, and I don’t anticipate that a similar effort will be made on the existing design, beyond what is currently published. Sorry for the news! This may be useful info in the meantime?
I’m very interested in those next-generation motors. I understand they’re the motors with integrated ESCs. I’m working on a project, and although I have everything designed to use T500 motors, I’d appreciate an honest answer as to when these motors will be available for purchase. Will it be this year? Thanks.
While the new motors may be released this year, the version with integrated ESC will likely take longer than that! Sorry we don’t have anything definitive on the timeline yet!
