Sensorless Control Method of the BLDC Motor Without Neutral Point

중성점을 사용하지 않는 BLDC 전동기 센서리스 제어 기법

  • 심광렬 (울산과학대 전기전자학부) ;
  • 안정렬 (동희홀딩스 미래자동차 부품연구소)
  • Received : 2011.07.05
  • Accepted : 2012.04.26
  • Published : 2012.09.01


Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensor. It is necessary to achieve the informations of rotor position for driving trapezoidal type brushless DC motor without any position sensor. In this paper, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converters, or the complex digital phase shift circuits which are indispensable in the conventional sensorless control algorithms. In the proposed method, in stead of detecting the zero crossing point of the nonexcited motor back electromagnetic force for the average motor terminal to neutral voltage, the commutation signal are extracted directly from the specific average line to line voltage with low-pass filter, adder and comparators circuit. In contrast to conventional methods, the neutral voltage is not need; therefore, the commutation signals are insensitive to the common mode noise. Moreover, the complex phase shift circuit can be eliminated. The effectiveness of the proposed method is verified through simulation results.


Supported by : 울산과학대학


  1. J.R. Hendershot Jr and TJE Miller, "Design of Brushless Permanent-Magnet Motors", Oxford Univ. Press, 1994
  2. T.J.E Miller, "Brushless Permanent-Magnet and Reluctance Motor Drives", Clarendon Press, Oxford 1989
  3. M. A. Rahman, "Modern Electric Motors in Electronic World", Proc. of IEEE IECON'93, pp.644-648, 1939
  4. K. Iizuka, H. Uzuhashi, M. Kano, T. Endo, and K. Mohri. "Microcomputer Control for Sensorless Brushless Motor". IEEE Trans. on Ind. Appli., IA-21(4):595-601, May/June 1985.
  5. S. Ogasawara and H. Akagi, "An approach to position sensorless drive for brushless dc motors", IEEE Trans. Ind. Applicat., vol. 27, pp. 928 - 933, Sept./Oct. 1991.
  6. R. Becerra, T. Jahns, and M. Ehsani, "Four quadrant sensorless brushless ECM drive", in Proc. IEEE Appl. Power Electron. Conf. and Expo., 1991, pp. 202-209.
  7. J. Shao, D. Nolan, M. Tessier, and D. Swanson, "A novel microcontroller based sensorless brushless (BLDC) motor drive for automotive fuel pumps", IEEE Trans. Ind. Appl., vol. 39, no. 6, pp. 1734-1740, Nov./Dec. 2003.
  8. P Pillay and R Krishnan, "Modeling, simulation, and analysis of permanent-magnet motor drives, Part I The brushless dc motor drive", IEEE Trans Indus Appl, vol 25, no 2, pp274-279, March/April 1989