3 research outputs found
A Review of Transverse Flux Machines Topologies and Design
High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling
Development of a Linear Vernier Hybrid Machine for direct drive wave energy converters
PhD ThesisThe work presented in this thesis concerns the development of linear electric machines
for use with wave energy converters. The machine topology selected, the Linear Vernier
Hybrid Machine, is extensively investigated, specifically looking at alternative magnet
configurations. Topologies are evaluated by their generation capabilities at low velocities, as
demanded by Direct Drive Wave Energy Converters. Attention is mainly focused on
improving the electromagnetic performance and reducing the magnet mass. A new topology
of the Linear Vernier Hybrid Machine is proposed for these purposes, known later as Inset
Magnet Consequent Pole machine. Tapered ferromagnetic poles are employed in this
topology, which have shown a great impact on minimising the inherent pole-to-pole leakage
flux as well as the unwanted cogging force.
Further investigation into the Inset Magnet Consequent Pole machine focuses on
improving the power factor through modifications made to the machine structure with no
increase in the mass magnet, steel or copper used. Two novel variants with the added benefit
of flux concentration effect are proposed and described. Finite Element Analysis is used to
optimize, analyse and compare the electromagnetic performances for the three investigated
machines.
Considering the complexity of manufacturing and number of components, two selected
topologies are built and tested in the laboratory, the Inset Magnet Consequent Pole machine
and V-shape Consequent Pole machine. The experimental results are compared to the
simulation results to validate the design. In general, a good agreement is shown between the
predicted and measured results. Afterwards, the experimental results obtained from the two
prototypes are compared with each other. These results verify that the proposed V-shape
Consequent Pole topology is superior in terms of no-load back EMF, force and power factor,
while it exhibits lower cogging force in comparison with the Inset Magnet Consequent Pole
topology. It is therefore concluded that the V-shape Consequent Pole machine is the best
compromise between power factor, efficiency and ease of manufacture. It has half the
number of components per pole of the best machine design presented, yet delivers 91% of
the force density and 93% of the power factor.
The last part of this thesis investigates the feasibility of using the proposed V-shape
Consequent Pole machine as an alternative design for an existing wave energy device
developed by Uppsala University to assess the effect of employing this sort of machine on
Abstract
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the overall machine size and costs. Five variants of the V-shape Consequent Pole machine
are described and comparedTechnical and Vocational Training Corporation, Saudi
Arabi