Method and system for determining deterioration of permanent magnets of electric apparatus
US8587244B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2011 |
| Grant date | Nov 19, 2013 |
| Priority date | — |
| Expiry date | Jun 19, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P29/032
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and a system for determining deterioration of permanent magnets of an electric apparatus to be inspected that facilitate determination without the need to remove the electric apparatus from a facility where it is installed. If the electric apparatus to be inspected is a three-phase linear motor, a current detector is used to acquire currents. A three-phase/two-phase conversion section converts the acquired currents into an α-axis current command and a β-axis current command. A locus of a current vector is computed based on the α-axis current command and the β-axis current command. A comparing and determining section compares the computed locus with a standard upper limit value stored in a storage means. If the number of times that the locus of the current vector exceeds the standard upper limit value exceeds a predetermined value, it is determined that the permanent magnets have been deteriorated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.