Method and apparatus for encoderless operation of a permanent magnet synchronous motor in an elevator
US6492788B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2000 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Nov 10, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2207/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet synchronous motor is controlled using d-axis current and q-axis current along with respective d-current and q-current feedback loops. The speed and position of the motor are determined by injecting a first signal into the d-axis current and observing the response in the q-current feedback loop. Part of the q-current feedback signal is demodulated with a second signal which is 90 degrees out of phase from the first signal. The demodulated signal is preferably sent through a low pass filter before being received by an observer controller. The observer controller outputs a position estimate which is used to modify the d-current feedback signal and a speed estimate which is used to modify the q-axis current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.