This thesis investigates stray losses in AC machines using the time-stepped finite element technique. Two aspects of this topic are involved in this thesis. The first aspect is to construct a finite element model for AC machine systems and develop an efficient numerical solution for the system equation; as the emphasis of this thesis, the second aspect is use the above model to analyze stray losses in AC machines under a variety of operation, design and manufacturing conditions.
The thesis modifies the traditional 2-D finite element technique to account for the variations in electromagnetic field along the machines axis resulting from skewed structures, rotor interbar currents and ventilation ducts. Domain decomposition and parallel computation are incorporated to efficiently give a numerical solution to the system equation.
The factors affecting harmonic stray losses in AC machines including pulse width modulation (PWM) supply, interbar resistance and slot shape are investigated using the above efficient analysis tool. Simulations and tests under different load conditions are carried out for an induction motor to investigate the additional harmonic stray loss caused by the PWM supply. For a large synchronous generator, simulations and tests are performed to study the effect of different amortisseur interbar resistances on the slot harmonic contents and the resulting harmonic stray loss in the amorisseur cage. As a factor influential to magnet stray loss in permanent magnet synchronous machines, various slot shape designs are assessed by simulations. An optimization based on an evolutionary strategy is implemented to find the best slot shape design with minimum machine loss.
The conclusions in the thesis provide valued information to direct the future design and manufacture of efficient AC machines. / Power Engineering and Power Electronics
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/928 |
| Date | 06 1900 |
| Creators | Zhan, Yang |
| Contributors | Andrew M. Knight (Electrical and Computer Engineering), John Salmon (Electrical and Computer Engineering), Marek Reformat (Electrical and Computer Engineering), Roger Toogood (Mechanical Engineering), Narayan Kar (Electrical and Computer Engineering, University of Windsor) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 1550810 bytes, application/pdf |
| Relation | Yang Zhan, Andrew M. Knight and Nick Stranges, Multislice inter-bar model for large synchronous machines with skewed stator slots, IEEE Transactions on Magnetics, vol. 45, no. 3, March 2009, pp. 1800 1803, Yang Zhan and Andrew M. Knight, Parallel time-stepped analysis of induction machines with Newton-Raphson iteration and domain decomposition, IEEE Transactions on Magnetics, vol. 44, no. 6, June 2008, pp. 1546 1549, A. Boglietti, A. Cavagnino, A.M. Knight and Y. Zhan, Factors affecting losses in induction motors with non-sinusoidal supply, The 42nd IEEE Industry Applications Society Annual Meeting, IAS 07, September 23 27, 2007, pp. 1193 1199, Yang Zhan and Andrew M. Knight, Slot shape optimization for permanent magnet synchronous machines by evolution strategy and time-stepped finite element analysis, The 17th International Conference on the Computation of Electromagnetic Fields, Compumag 2009, November 22 26, 2009, Andrew M. Knight and Yang Zhan, Identification of flux density harmonics and resulting iron losses in induction machines with nonsinusoidal supplies, IEEE Transactions on Magnetics, vol. 44, no. 6, June 2008, 1562 1565 |
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