Abstract
We have studied electromagnetic losses of a frequency-converter-fed cage-induction motor by using a numerical machine model that includes eddy-current and hysteresis phenomena in electrical steel sheets. We used the model to solve the two-dimensional (2-D) time-harmonic field and winding equations of a cage-induction machine, utilizing a finite-element method and phasor variables. We used complex reluctivity to couple the hysteresis and eddy currents in the sheets with the 2-D analysis. The model modifies the absolute value of the reluctivity according to a one-dimensional (1-D) eddy-current solution developed in the lamination thickness. To define the argument of the reluctivity, we applied both the 1-D field solution and measured hysteresis data. We compared computations of additional electromagnetic losses in a 37-kW test machine due to the higher harmonics of a frequency-converter supply with experimental results. The agreement is found to be reasonable.
| Original language | English |
|---|---|
| Article number | 5089908 |
| Pages (from-to) | 2981-2989 |
| Number of pages | 9 |
| Journal | IEEE Transactions on Magnetics |
| Volume | 45 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 1 Jul 2009 |
| MoE publication type | A1 Journal article-refereed |
Funding
ACKNOWLEDGMENT This work was supported in part by ABB Oy, Academy of Finland, and Graduate School in Electrical and Communications Engineering. The first author would like to acknowledge Dr. A. Belahcen from Department of Electrical Engineering, Helsinki University of Technology for the useful discussions.
Keywords
- Eddy currents
- Finite-element methods
- Induction motors
- Losses