Method and system for sensorless brushless DC motor control with predictive switch timing
US7514888B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2006 |
| Grant date | Apr 7, 2009 |
| Priority date | — |
| Expiry date | Dec 11, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/21
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and system for providing sensorless brushless DC motor control using predictive switch timing requires connecting a stator coil in a bridge configuration, applying a positive excitation voltage across the coil for a predetermined time period, deactivating the excitation voltage, and monitoring the voltage (VEMF) generated due to electro-motive force (EMF) across the coil. The polarity of VEMF changes when the rotor has moved a known distance—typically 90°. After detecting a polarity change, a negative excitation voltage is applied across the coil, deactivated, and VEMF monitored to detect a polarity change. This sequence is repeated to maintain the rotation of the rotor. The motor is preferably set into motion using a start-up routine, which also determines the predetermined time period used during steady-state operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.