Switched reluctance motor controller with sensorless rotor position detection
US5859518A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1997 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Dec 22, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/089
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A controller for a switched reluctance motor that does not utilize a sensor for detecting the rotational position of the rotor. The inductance of each field winding changes according to the rotational position of the rotor. The rotational position of the rotor of the motor is determined by measuring the inductance of each phase during periods when a minimum level of inductance for the phase is expected to occur. A series of voltage pulses are applied to the appropriate field winding during the appropriate period while the current produced in response to the voltage pulses is measured. The relationship between applied voltage, measured current, and time, is utilized to determine the inductance value as it decreases and then increases between positions of rotor alignment. Commutation to a next phase is performed based upon the measured inductance values. More particularly, a first voltage pulse is applied to an appropriate field winding after a commutation and a level of current induced by the voltage pulse is stored across a capacitor. Then, subsequent current levels produced by subsequent voltage pulses are compared to a predetermined threshold. The predetermined threshold ensures …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.