Method of determining the rotor position of a permanent-magnet motor
US9088235B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 2013 |
| Grant date | Jul 21, 2015 |
| Priority date | — |
| Expiry date | Jan 17, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of determining the position of a rotor of a permanent-magnet motor. The method includes sequentially exciting and freewheeling a winding of the motor. The winding is freewheeled for a freewheel period in response to current in the winding exceeding a current limit. The method also includes measuring a parameter that corresponds to either the magnitude of current in the winding at the end of the freewheel period or the interval between the start or end of the freewheel period and the time at which current in the winding exceeds the current limit. The measured parameter is then compared against a threshold and the rotor is determined to be at a predetermined position when the measured parameter is less than or greater than the threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.