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Title: Investigation on electromagnetic performance of doubly salient synchronous reluctance machines
Author: Ma, Xiyun
ISNI:       0000 0004 7431 8636
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2018
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This thesis investigates the electromagnetic performance of the novel doubly salient synchronous reluctance machines (DSRMs) with different winding configurations, excitation methods, stator and rotor structures, and slot/pole number combinations. Both the wellestablished DSRMs with double layer conventional and mutually-coupled windings, as well as the fully-pitched winding have been compared against those proposed DSRMs. Different current waveforms such as rectangular wave and sinewave excitations have been considered in the comparison. It is worth mentioning that with rectangular wave excitation, the DSRM is in effect a classic switched reluctance machine (SRM). With rectangular wave excitation, different conduction angles such as unipolar 120° elec., unipolar/bipolar 180° elec., bipolar 240° elec., and bipolar 360° elec., have been adopted and the most appropriate conduction angles have been obtained for the SRMs with different winding configurations. In order to achieve improved machine performance, simpler manufacturing process and better fault tolerant capability, several novel modular SRMs have been proposed with different slot/pole number combinations, flux gap widths, and winding configurations. With appropriate conduction angles, the modular SRMs with higher rotor pole number than stator slot number are found to produce similar average torque, but much lower torque ripple, iron loss and radial force when compared with non-modular SRMs. With sinewave excitation, both the static and dynamic performances (torque-speed curve, efficiency map, etc.) of the DSRMs with different winding configurations have been investigated in-depth. In order to obtain the maximum efficiency, appropriate winding configuration can be selected for different speed range applications. In order to compare with the conventional synchronous reluctance machines (SynRMs) having flux barriers inside the rotor, the appropriate rotor topologies together with different winding configurations and slot/pole number combinations for maximum average torque generation have been obtained. Moreover, for better understanding of the nature of the DSRMs and distinguishing the double/single layer conventional and mutually-coupled winding configurations, analytical models on the basis of magneto-motive force (MMF) and airgap permeance have been developed to analyse the contribution of airgap flux density harmonics to average torque and torque ripple. Furthermore, some prototypes have been built with different winding configurations, stator structures (modular and non-modular) and slot/pole number combinations to validate the predictions.
Supervisor: Li, Guang-jin Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available