Circuit and method for sensorless control of a permanent magnet brushless motor during start-up
US9000696B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2013 |
| Grant date | Apr 7, 2015 |
| Priority date | — |
| Expiry date | Sep 14, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/182
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The system discloses structure for synchronizing sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A drive voltage drives a plurality of the stator windings thereby producing a magnetic field. On an undriven stator winding among the stator windings, a voltage induced by the magnetic field is sampled. The induced voltage changes as a function of a magnetic rotor transitioning across a plurality of angular positions. A first value corresponding to the sampled voltage induced on the currentless winding is compared with a commutation threshold to determine a proper commutation point. The system is switched to a next drive configuration of the sequence when the first value surpasses the threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.