Electronic Science and Technology ›› 2019, Vol. 32 ›› Issue (3): 67-71.doi: 10.16180/j.cnki.issn1007-7820.2019.03.014

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A New Trapezoidal Control Method of Sensorless BLDCM

WANG Xingfang,JIN Shiqun,XING Jinyu,HOU Shaoyang,WANG Zhe   

  1. National Key Laboratory of Advanced Display Technology,Key Laboratory of Special Display Technology of theMinistry of Education,Academy of Photoelectric Technology,Hefei University of Technology,Hefei 230009,China
  • Received:2018-03-18 Online:2019-03-15 Published:2019-03-01
  • Supported by:
    Ministry of Science and Technology of the People’s Republic of China(2013YQ220749);National Natural Science Foundation of China(51475133)


Sensorless brushless DC motor is mainly controlled by the back-EMF method. However, a variety of disturbances in the control method will cause glitches and ripples in the waveform of Back-EMF,leading to erroneous judgment of the zero-crossing point of Back-EMF. In this paper, a sensorless BLDCM control method was proposed, and the proposed optimal function was used to filter the results of the Back-EMF detection. By analyzing the back EMF waveform, the optimal function was used to filter the glitches and ripples near zero-crossing point of the Back-EMF to avoid the misjudgement of the zero crossing point of the back EMF. Finally, the commutation time of the motor drive voltage was obtained, and the level of precise control of motor was improved. Experimental results proveed the correctness and feasibility of the new BLDCM sensorless trapezoidal control method.

Key words: BLDCM, sensorles, Back-EMF, zero crossing detection, glitch pulse, optimal function filtering

CLC Number: 

  • TP13