Method and apparatus for estimating induction motor rotor temperature
US7769552B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 2008 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Nov 11, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2207/01
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus to provide continuous and reliable rotor temperature estimates for line-connected induction motors during steady-state and/or dynamic motor operations. Rotor temperature is calculated from voltage and current measurements without any temperature or speed sensors. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Fourth, the rotor time constant is estimated in a model-reference adaptive system based on a dynamic induction motor equivalent circuit model. Finally, the rotor temperature is calculated according to the linear relationship between the rotor temperature and the estimated rotor time constant. Real-time induction motor thermal protection is achieved through this continuous tracking of the rotor temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.