Methods and apparatus for estimating rotor slots
US8131482B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 2008 |
| Grant date | Mar 6, 2012 |
| Priority date | — |
| Expiry date | Nov 9, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/343
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of determining a quantity of rotor slots in an induction motor through analysis of voltage and current signals. An approximate slip is calculated according to an approximate slip function that is independent of a rotor slots quantity. A fundamental frequency is calculated from a representation of the voltage signal. A saliency frequency is calculated from a representation of the current signal. For each rotor slots index in a set of rotor slots indices, a slip estimate is calculated according to a slip estimation function that includes the saliency frequency, a saliency order, the fundamental frequency, a rotor slots index in the set of rotor slots indices, and a quantity of poles of the motor, such that the slip estimate is evaluated at respective ones of the set rotor slots indices. A slip estimation error signal is calculated according to a slip estimation error function that includes a difference between the approximate slip and respective ones of the slip estimates. A rotor slots performance surface representative of an aggregate of the slip estimation error signals evaluated over the set of the rotor slots indices is calculated. A rotor slots quantity equal to the ro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.