Alternating-current motor control apparatus
US8330402B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 20, 2010 |
| Grant date | Dec 11, 2012 |
| Priority date | — |
| Expiry date | Apr 24, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2203/11
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An alternating-current motor control apparatus includes a voltage controller configured to output a command voltage vector so that the command voltage vector is time-averaged for time periods, a square-wave voltage generator configured to control, every time period, amplitudes and phases of voltages to be applied to an alternating-current motor, a current detector configured to detect motor currents at a timing synchronized with periods 1/N-th of the time periods, where N is equal to or larger than one, a coordinate transformation section configured to perform coordinate transformation to transform the motor currents into two-phase currents, an envelope extractor configured to extract two-phase currents as waveforms having amplitudes that periodically change from the two-phase currents, and extract envelopes of the waveforms, and a magnetic-pole-position computing section configured to compute a magnetic-pole position using the envelopes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.