Speed control of sensorless brushless dc motor by computing back emf from line voltage difference

R. Sivakami, Thangaraj K.


Sensorless operation of permanent magnet brushless direct current (BLDC) motor drive controls the rotating speed with different applied voltage. No phase lagging is produced which leads to increase the efficiency and minimize the torque pulsation of the BLDC motor. Initially, motor can be started by following the v/f method then allows the sensorless mode after reaching the minimum speed of 500-1000rpm.The Sensorless BLDC motors are highly used due to higher efficiency, reliability power, acoustic noise, smaller, lighter, greater dynamic response, better speed versus torque characteristics, higher speed range and longer life. Thus the source voltage spikes and switching losses are reduced. This method can be demonstrated through MATLAB stimulation and DSP TMS 320LF2407A is used in the experimental setup to get the output


Ang, G.H.; Park, J.H.; Chang, J.H. Position Detection and Start-Up Algorithm of a Rotor in a Sensorless BLDC Motor Utilising Inductance Variation. IEEE Proc.-Electr. Power Appl. 2002, 149, 137-142.

P. P. Acarnley and J. F Watson, “Review of position-sensorless operation of brushless permanent-magnet machines,” IEEE Trans. Ind. Electron., vol. 53, no. 2, pp. 352–362, Apr. 2006

P. P. Carney and J. F Watson, “Review of position-sensor less operation of permanent-magnet machines,” IEEE Trans. Ind. Electron., vol. 53, no. 2, pp. 352–362, Apr. 2006

P. Damodharan, R. Sandeep, and K. Vasudevan, “Simple position sensor less starting method for brushless DC motor,” IEEE Electro. Power Appl., vol. 2, no. 1, pp. 49–55, Jan. 2008

J.X. She and S. Iwasaki, “Sensor less control of ultrahigh-speed PM brushless motor using PLL and third harmonic back EMF,” IEEE Trans. Ind. Electron., vol. 53, no. 2, pp. 421–428, Apr. 2006.

D.-H. Jung and I.-J. Ha, “Low-cost sensorless control of brushless DC motors using a frequency-independent phase shifter,” IEEE Trans. Power Electron., vol. 15, no. 4, pp. 744–752, Jul. 2000.

B. Terzic and M. Jadric, “Design and implementation of the extended Kalman filter for the speed and rotor position

estimation of brushless DC motor,” IEEE Trans. Ind. Electron., vol. 48, no. 6, pp. 1065–1073, Dec. 2001.

Shao J., An improved microcontroller-based sensorless brushless DC(BLDC) motor drive for automotive applications. IEEE Trans. Ind. Appl. 42(5): 1216-1222 (2006).

Lai Y.-S. Lin Y.-K., A unified approach to zero crossing point detection of back EMF for Brushless DC motor drives without current and hall sensors. IEEE Trans. Power Electron. 26(6), (2011).

P. Damodharan and Krishna Vasudevan, Sensorless Brushless DC Motor Drive Based on the Zero-Crossing Detection of Back Electromotive Force (EMF) from the Line Voltage Difference, IEEE Trans on energy conversion, vol. 25, no. 3, september 2010.

C.-H. Chen and M.-Y. Cheng, “New cost effective sensorless commutation method for brushless dc motors without phase shift circuit and neutral voltage, vol. 22, no. 2, pp. 644–653, Mar2007.

G.-J. Su and J. W. McKeever, “Low cost sensorless control of brushless DC motors with improved speed range vol. 19, no. 2, pp. 296–302, Mar. 2004.

T.-H. Kim and M. Ehsani, “Sensorless control of BLDC motors from near-zero to high speeds, ” Power Electron., vol. 19, no. 6,pp. 1635–1645, Nov. 2004.

R. Krishnan and R. Ghosh, “Starting Algorithm and Performance of A PM DC Brushless Motor Drive System with No Position Sensor,” in Proc. IEEE PESC’89, PP.815–821, 1989.

Tae-Hyung Kim and M. Ehsani, "Sensor less Control of the BLDC Motors from Near-Zero to High Speeds," IEEE Trans. Power Electron. vol. 19, No.6, pp.1635-1645, Nov. 2004.

Total views : 91 times


  • There are currently no refbacks.

View IJAAS Stats

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.