A Practical Sensorless Commutation Method Based on Virtual Neutral Voltage for Brushless DC Motor

摘要

This paper presents a low-cost and highly practical sensorless control method for brushless DC (BLDC) motor drives. The developed methodology can generate an accurate commutation signal for the BLDC motor by sensing the back electromotive force zero-crossing point through the virtual neutral voltage of the motor. Since commutation control is critical for the BLDC motor control, a voltage-controlled phase shifter comprising a hysteresis comparator and voltage-controlled resistor is proposed in order to perform phase compensation at different speeds and prevent rapid output oscillations due to noise or high-frequency ripples in the virtual neutral voltage. Finally, several experiments have been performed on a prototype motor to verify the theoretical analysis and demonstrate the practicality and reliability of the proposed sensorless drive method. (C) 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.