Design, comparison and experimental evaluation of non-overlap winding radial flux permanent magnet hub drives for electric vehicles

[摘要] ENGLISH ABSTRACT: The focus of this thesis is on the optimal design, control and evaluation of 3-phase permanentmagnet radial flux synchronous machines with non-overlapping, concentrated-coil, doublelayer stator windings for EV hub drive applications.A simple analytical method is developed that can be used as a first design tool. The methoduses and predicts the MMF harmonic content for a certain pole-slot combination as well asthe harmonic content for the air gap permeance function. These harmonics are then used tocalculate the torque and torque ripple of machines with large stator slot openings and surfacemounted permanent magnets.A different approach to calculate the iron, stator copper eddy current and magnet lossesis presented. This method specifically looks at the machine during field weakening operationwhen the flux paths are changing in the machine. Flux density information throughout themachine is extracted from a series of static FE solutions, to calculate the losses and to combinethis 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 aftera 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 preformedcoils and semi-closed stator slots. Two prototype machines, one with a good winding factorand the other with a low winding factor, are built and compared. The manufacturing andtesting of the two prototype machines are described and shown in detail.

[发布机构] Stellenbosch University