Axial Flux Permanent Magnet coreless machine

Kaliyev, Vladislav (2015) Axial Flux Permanent Magnet coreless machine. [USQ Project]


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Axial Flux Permanent Magnet (AFPM) machines are becoming increasingly popular due to introduction of the second generation of rare-earth permanent magnets. Owing their unique construction and many advantages, AFPM machines have extensive topology and applications. Among them the coreless AFPM (without ferromagnetic material in the stator) offer reduced cogging torque which proved to be particular useful for special applications, e.g. low power wind energy generation, hub motors of electrical vehicles and electrical bicycles.

A Double Stator Internal Rotor prototype was designed and constructed to investigate the performance of the coreless construction. This geometry (not very popular due to poor winding utilisation) has an advantage of using less PMs. Polyester resin was used to hold eight cylindrical shape magnets of the eight pole machine. The large effective air gap of the coreless machine was minimised by keeping a physical air gap and the axial thickness of the trapezoidal stator coils to the minimum, after measuring the magnetic flux distribution around the rotor circular poles. Three types of stators were manufactured to enable a performance comparison: a blank without any conductors for mechanical losses estimation, a ribbon wire coreless and a ribbon wire with magnetic powder composite backing.

Test Results confirmed the limitations of the prototype’s geometry and the validity of the AFPM design parameters. The magnetic powder composite backing countered the unfavourable magnetic flux distribution of the internal rotor allowing for increase in power output compared to the stator without backing. Both types of conductor stators do not have a cogging torque with EMF outputs being very close to pure sinusoidal. Ribbon shape of the coil conductor was very beneficial in producing thin rigid coils of large diameter. This might prove to be invaluable in a multi-disc configuration.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Electrical & Electronic Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Supervisors: Helwig, Andreas
Date Deposited: 06 Jun 2016 23:19
Last Modified: 06 Jun 2016 23:19
Uncontrolled Keywords: Axial Flux, Coreless, Wind Generation, Permanent Magnet, Cogging Torque
Fields of Research (2008): 09 Engineering > 0906 Electrical and Electronic Engineering > 090699 Electrical and Electronic Engineering not elsewhere classified
Fields of Research (2020): 40 ENGINEERING > 4008 Electrical engineering > 400899 Electrical engineering not elsewhere classified

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