Rotor Position Phase Correction for Sensorless Brushless DC Motor Based on Line Back EMF

Abstract:

This paper proposes a novel rotor position estimation method based on line back EMF for brushless DC motor (BLDCM). The relationship between position phase error and the symmetric line back EMF is analyzed. It is noted that line back EMF error can exactly reflect rotor position phase error. If the amplitude of line back EMF at the beginning of commutation is equal to the amplitude of line back EMF at the end of commutation, the waveform of line back EMF should be symmetric. Based on the above analysis, a closed loop control method to correct rotor position phase is presented. Line back EMF error is employed to keep the waveform of line back EMF symmetrical by PI controller. This paper also develops a sensorless BLDCM driver to implement the proposed method based on DSP and the experimental results prove the validity of the proposed method.

• Periodical: Advanced Materials Research (Volumes 347-353)
• Pages: 607-610
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.347-353.607
• Online since: October 2011
• Authors: Zi Cheng Li, Zi Yu Ou, Shan Mei Cheng
• Keywords: Brushless Direct Current Motor (BLDCM), Line Back EMF, Phase Error, Position Sensorless

References

[1] H. X. Wu, S. K. Cheng, S. M. Cui, "A controller of brushless dc motor for electric vehicle," IEEE Transactions on Magnetics, vol. 41, no.1, p.509–513, 2005.

DOI: 10.1109/tmag.2004.839304

[2] K. Y. Cheng, and Y. Y. Tzou, "Design of a sensorless commutation IC for BLDC motors," IEEE Transactions on Power Electronics, vol. 18, no.6, p.1365–1375, 2003.

DOI: 10.1109/tpel.2003.818867

[3] Z. Li, S. Cheng, Y. Qin and K. Cai, "A novel line-to-line back EMF calculation for sensorless brushless DC motor drivers," the 11th International Conference on Electrical Machines and Systems, vol.1, p.1406–1411, 2008.

[4] G. H. Jang, and M. G. Kim, "Optimal commutation of a BLDC motor by utilizing the symmetric terminal voltage," IEEE Transactions on Magnetics, vol. 42, no.10, p.3473–3475, 2006.

DOI: 10.1109/tmag.2006.879069

[5] J. Shao, D. Dolan, M. Teissier, and D. Swanson, "A novel microcontroller-based sensorless brushless DC motor drive for automotive fuel pumps," IEEE Transactions on Industry Applications, vol. 39, no.6, p.1734–1740, 2003.

DOI: 10.1109/tia.2003.818973

[6] C. H. Chen, and M. Y. Cheng, "A new cost effective sensorless commutation method for brushless DC motors without phase shift circuit and neutral voltage," IEEE Transactions on Power Electronics, vol. 22, no.2, p.644–653, 2007.

DOI: 10.1109/tpel.2006.890006

[7] D. H. Jung, and I. J. Ha, "Low-cost sensorless control of brushless DC motors using a frequency-independent phase shifter," IEEE Transactions on Power Electronics, vol. 15, no.4, p.744–752, 2000.

DOI: 10.1109/63.849045