Design of segmented outer rotor permanent magnet flux switching motor in transverse shape for high torque applications
The use of an outer rotor electric motor for electric vehicle applications has gained a lot of attention since the motor has high torque density and power. Outer rotor motors have performance indices that should be taken into consideration because not every machine is effective. Recently, oute...
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| Format: | Thesis |
| Language: | English English English |
| Published: |
2020
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/899/1/24p%20ENWELUM%20MBADIWE%20IGNATIUS.pdf http://eprints.uthm.edu.my/899/2/ENWELUM%20MBADIWE%20IGNATIUS%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/899/3/ENWELUM%20MBADIWE%20IGNATIUS%20WATERMARK.pdf |
| Summary: | The use of an outer rotor electric motor for electric vehicle applications has gained a
lot of attention since the motor has high torque density and power. Outer rotor motors
have performance indices that should be taken into consideration because not every
machine is effective. Recently, outer rotor hybrid excitation flux switching motor (OR�HEFSM) in salient rotor has become attractive for providing high torque and high
power. It uses two flux sources and single tooth winding. Regrettably, salient rotor
and complex stator of HEFSM with single tooth winding have inherited high iron loss
and high winding loss. Furthermore, HEFSM uses a high volume of permanent magnet
(PM), suffers demagnetisation and low permeability resulting in poor performance. In
another development, outer rotor field excitation FSM (OR-FEFSM), using dovetail
segmented rotor in concentrated winding, has been presented for low-cost and high
power-density. The OR-FEFSM using concentrated winding is capable of providing
high power-density and sinusoidal back-emf, reasonable torque ripple and high net
peak-torque. However, the problem of ORFEFSM is the utilisation of high number of
stator teeth, high number of rotor segments and high number of copper conductor.
These high materials usage lead to high iron and copper losses that affect performance
of motor. This thesis deals with a newly designed structure of the segmented outer
rotor permanent magnet flux switching motor in transverse shape (SegOR-PMFSM)
with minimal iron and copper losses, high permeability, high torque and power output.
The JMAG-Designer version 14 is utilised as the 2D finite element analysis (2D-FEA).
For the three-phase operation, a 24 stator-teeth with feasible poles like 8, 10, 14, 16,
22 and 26 was designed, analysed and the results were compared based on torque and
power performances. The 24S/14P motor is selected for securing the initial highest
torque of 240.5 Nm and achieved the target average torque/power of 470 Nm/45 kW
after using parameter optimisation method (POM). This result was compared with OR�HEFSM having torque/power of 335 Nm/123 kW and OR-FEFSM having
torque/power of 380 Nm/29 kW. Meanwhile, the torque achieved with SegOR-vi
PMFSM is 28.72 % and 19.14 % higher than OR-HEFSM and OR-FEFSM. Motor’s
torque density and power density, at maximum armature current density are calculated
to be 76.66 kNm/m3 and 7339.5 kW/m3
respectively. Therefore, the torque of 24S/14P
topology in a segmented transverse shape has produced higher average torque than
using salient rotor pole and dovetail segmented rotor in the machine design. The results
obtained affirm good agreement with high torque for light-weight electric vehicle
applications. The favourable high torque and power output of the proposed SegOR�PMFSM present it as a viable core component for electric vehicle application.
However, this research is limited to 2D simulation analysis without experimental
evaluations due to none availability of the testing equipment and the motor’s weakness
is potential high induced emf. |
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