A reliable initial rotor position estimation method for sensorless control of interior permanent magnet synchronous motors

Xuan Wu, S. Huang, Ping Liu*, Ting Wu, Y. He, Xiaofei Zhang, Kun Chen, Qiuwei Wu

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


In this paper, a novel initial rotor position estimation method for reliable start-up of the IPMSM is presented. The proposed method combines the improved high frequency pulse signal injection with positive and negative d-axis current bias injection. Differing from the conventional initial rotor position detection scheme, the injection and the field-oriented control periods are separated in the proposed method. Therefore, the filters are not needed in the process of high-frequency response current and fundamental current extraction. The magnet polarity can be estimated by exciting the positive and negative d-axis currents. Afterwards, the peak values of d-axis current during the voltage injection period are accumulated to detect the rotor magnetic polarity. The proposed method can improve the reliability of the magnet polarity detection. Moreover, it is suitable for both the standstill rotor application and the free-running rotor application. The effectiveness of the proposed method is verified on a 1.5 kW IPMSM drive platform.

Original languageEnglish
JournalISA Transactions
Pages (from-to)116-129
Publication statusPublished - 1 Jan 2020


  • High frequency pulse voltage injection
  • Initial rotor position estimation
  • Interior permanent magnet synchronous motor (IPMSM)
  • Magnetic polarity detection
  • Sensorless

Cite this