الفهرس 
Ch1 IntroductionOnly 14 pages are availabe for public view
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Abstract
Owing to growing concerns on energy utilization and environmental protection,
research on electric vehicles and wind power generation has drawn much attention in
the past few decades. As a key component of these applications, the development of
electric machines has become an important research topic since the last century. The
permanent-magnet brushless machines have dominated the industrial and domestic
markets, for many years due to their outstanding performances when compared to their
counterparts. However, the PM material takes disadvantages of relatively high cost,
limited resource, and uncontrollable magnetic flux, which makes it become
increasingly important to consider reduced or even no PM FSMs. Therefore, with the
absence of PM materials, the advanced magnetless doubly salient brushless machines
that provide great cost-effectiveness have become more popular recently. These
machines are called “Flux Switching Machines”.
The flux switching machine (FSM), or also called switched flux machine, falls into
a family of machines with an excitation source in the stator. This machine operates on
the principle that the EMF is generated from coupling of flux through coils by virtue
of a salient rotor providing varying permeance along the air-gap. The flux switching
machine has been actively studied over the past decades as it offers high efficiency and
high-power density.
The purpose of this thesis is to investigate the characteristics of existing
magnetless flux switching machines, analyze their design philosophies and propose
new topologies for various applications. Firstly, the background of magnetless
machines and previous works conducted by other researchers are introduced. Based on
the study of the existing works, the upcoming trend and the potential development are
also reviewed. Secondly, a new three-phase inner rotor Flux Switching Generator
(FSG) is investigated for two different rotors. Next, a novel structure with improved
power-density, namely the dual-rotor three-phase FSM, is proposed for aircraft power
generation and wind power generation. Then, all the key performances of the proposed
machines are thoroughly analyzed by the finite element method (FEM), while the
experimental setups have also been developed to verify the proposed concepts. Finally,
a comparison between the inner-rotor and the dual-rotor topologies of FSMs is
provided to show the potentials of each topology for modern industrial applications.