25.6. BLDC sensorless over-zero control

25.6.1. Overview

This project shows a sensorless control method for brushless motors - Control by trapezoidal wave algorithm

  • Reverse electric potential over zero method to detect commutation moment

  • Speed control

25.6.2. Configurations

  • This program uses the BLM57050-1000 brushless motor of “Leisai Intelligence”, please refer to the Leisai Intelligence website for the specific parameters of the motor.

  • Board settings refer to the development board documentation Motor Pin related content

  • Requires board to support phase current acquisition

  • Note

    The motor driver board J6 J7 J12 to be connected to UU UV UW.

25.6.3. Running the demo

The motor accelerates at speeds from 5 to 40 revolutions per second when the project is running correctly, then decelerates from 40 to 5 revolutions per second and keeps cycling.

Warning

  • After the motor is powered on, it will first perform the “alignment” action. If the motor is disturbed at this time, it will produce a jitter.

  • Pay attention to the current size, when abnormalities occur, please cut off the power at any time