AC motor control apparatus
US8917040B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2013 |
| Grant date | Dec 23, 2014 |
| Priority date | — |
| Expiry date | Jul 18, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P21/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control circuit calculates an α-axis current iα and a β-axis current iβ in a fixed coordinate system based on a W-phase (sensor phase) of an AC motor. The control circuit calculates, at each switching time point and each intermediate time point, the α-axis current iα from a current iw.sns sensed in the W-phase, and the β-axis current iβ from a differentiated value Δiα determined from the variation quantity of the α-axis current between every two successive switching time points or intermediate time points. Subsequently, the control circuit calculates a current phase xθ=tan−1(iβ/iα) relative to the W-phase. Subsequently, the control circuit calculates an estimation factor according to the current phase xθ and determines an estimated current iu.est in the U-phase of the AC motor by multiplying the sensed current iw.sns by the calculated estimation factor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.