Doctoral Degrees (Electrical and Electronic Engineering)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/327

Browse

Browsing Doctoral Degrees (Electrical and Electronic Engineering) by Subject "3-phase permanent magnet radial flux synchronous machines"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Design, comparison and experimental evaluation of non-overlap winding radial flux permanent magnet hub drives for electric vehicles
    (Stellenbosch : University of Stellenbosch, 2011-03) Rix, Arnold Johan; Kamper, M. J.; University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.
    ENGLISH ABSTRACT: The focus of this thesis is on the optimal design, control and evaluation of 3-phase permanent magnet radial flux synchronous machines with non-overlapping, concentrated-coil, double layer stator windings for EV hub drive applications. A simple analytical method is developed that can be used as a first design tool. The method uses and predicts the MMF harmonic content for a certain pole-slot combination as well as the harmonic content for the air gap permeance function. These harmonics are then used to calculate the torque and torque ripple of machines with large stator slot openings and surface mounted permanent magnets. A different approach to calculate the iron, stator copper eddy current and magnet losses is presented. This method specifically looks at the machine during field weakening operation when the flux paths are changing in the machine. Flux density information throughout the machine is extracted from a series of static FE solutions, to calculate the losses and to combine this with an empirical formula. Some machine topology choices are compared for use as hub drives in small electric ve- hicles. The parameters that influence the machine design are discussed and evaluated after a multidimensional design optimization is done and an efficient control algorithm is imple- mented. The algorithm works through the entire operating speed range and make use of, automatically generated, 2D look up tables to determine the correct current reference. A stator lamination design is proposed, that combines the use of rectangular preformed coils and semi-closed stator slots. Two prototype machines, one with a good winding factor and the other with a low winding factor, are built and compared. The manufacturing and testing of the two prototype machines are described and shown in detail.