Dear STM Community,
While researching BLDC motor control methods, I came across this community. Recently, I have been experimenting with sensorless FOC control of a small BLDC motor using the B-G431B-ESC1 speed controller together with STM32 Motor Control Workbench and the Motor Control SDK.
For my application, I require a speed accuracy of approximately ±10 RPM at speeds of up to 70,000 RPM. In my initial setup using the STM32 Motor Control SDK, I was able to achieve a speed stability of roughly ±100 RPM on a motor with a maximum speed of 3,000 RPM.
I am wondering whether this performance can be significantly improved through further tuning of the control loops (e.g., PI controller parameters such as Kp and Ki) or whether there are fundamental limitations of sensorless BEMF-based control that would make achieving ±10 RPM unrealistic - in that case, what alternatives exists?.
As I am relatively new to FOC, I would appreciate your advice on whether this approach is suitable for my application. In particular, I have the following questions:
1. How accurately can a BLDC motor be controlled using sensorless FOC based on back-EMF (BEMF) estimation?
2. The B-G431B-ESC1 is limited to approximately 28 V and 40 A. For my target application, I require a controller capable of driving motors at speeds up to 70,000 RPM with power levels of up to 1.5 kW. Does anyone know of a suitable controller platform that supports sensorless FOC at this power level?
I searched the STMicroelectronics website but mainly found power stages and inverter boards, such as the STEVAL-IPM10B, rather than complete controller solutions. Ideally, I am looking for something similar to the B-G431B-ESC1 but designed for significantly higher power.
Project Background
This work is part of a university research project involving precise control of high-speed BLDC motors for biological experiments. If anyone has experience with high-speed motor control, sensorless FOC at very high RPMs, or even reverse engineering and extending the capabilities of the B-G431B-ESC1, I would be very interested in discussing potential collaboration. Or does someone has experience with STM it self, if they are coorperating for custom design?
Any advice, recommendations, or experiences would be greatly appreciated.
Thank you in advance for your help.
Best regards,
Leo
