Induction motor speed determination by flux spectral analysis
US5530343A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1994 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Oct 7, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/48
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for determining the rotational speed of an AC induction motor based on a spectrum analysis of a magnetic flux signal. For a Phase I analysis, which is usually sufficient, three sets of families of peaks indicative of possible rotational speeds are defined, and the flux frequency spectrum is searched for peaks meeting the family definitions to determine candidate speeds, and to assign scores. If there is a candidate speed with an overall score which exceeds a predetermined threshold, the motor rotational speed is determined as that candidate speed. A Phase II analysis, employing a more exhaustive set of five additional family definitions, is applied when Phase I fails to reach a result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.