Abstract
This paper presents a low-cost position sensorless control scheme for brushless dc motors. Rotor position information is extracted by indirectly sensing the back EMF from only one of the three motor-terminal voltages for a three-phase motor. Depending on the terminal voltage sensing locations, either a low-pass filter or a band-pass filter is used for position information retrieval. This leads to a significant reduction in the component count of the sensing circuit. The cost saving is further increased by coupling the sensing circuit with a single-chip microprocessor or digital signal processor for speed control. In addition, a look-up-table-based correction for the nonideal phase delay introduced by the filter is suggested to ensure accurate position detection even at low speed. This extends the operating speed range and improves motor efficiency. Experimental results are included to verify the proposed scheme.
| Original language | English |
|---|---|
| Pages (from-to) | 296-302 |
| Number of pages | 7 |
| Journal | IEEE Transactions on Power Electronics |
| Volume | 19 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 2004 |
Funding
Manuscript received January 18, 2002; revised October 31, 2003. This paper was presented at the 2002 Applied Power Electronics Conference and Exposition (APEC 2002), Dallas, TX, March 10–14, 2002. This work was supported by the Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract DE-AC05-00OR22725. Recommended by Associate Editor J. Ojo.
Keywords
- Band-pass filter
- Brushless dc motors
- Digital signal processor
- EMF
- Low-pass filter
- Rotor
- Sensorless control scheme
- Single-chip microprocessor