Fredrik Bajers Vej 5
Postboks 159 9100 Aalborg
Telefon: 9940 9940
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06.11.2017 kl. 13.00 - 06.11.2017 kl. 16.00
Xiaoxu Zhang, Department of Energy Technology, will defend the thesis "Design and Analysis of Magnetic Transmission Devices for Low-Speed High-Torque Application".
Design and Analysis of Magnetic Transmission Devices for Low-Speed High-Torque Application
Professor Zhe Chen
Associate Professor Weihao Hu
Associate Professor Kaiyuan Lu, Dept. of Energy Technology, Aalborg University (Chairman)
Associate Professor Henk Polinder, Delft University of Technology, the Netherlands
Professor Ed Spooner, University of Durham, UK
There is an increasing demand for low-speed and high-torque transmission from wind power generation to ship propulsion. Generally, the low-speed and high-torque transmission system could be classified into the mechanical-geared-drive solution and direct-drive solution. The mechanical-geared-drive solution usually suffers from the issues associated with the mechanical gearbox, such as the need for lubrication, wear between contacting surfaces, noise and vibration, etc. Although the direct-drive solution could operate without mechanical gearbox, the direct-drive machines rotate at low speed, which would lead to a bulky size. The purpose of this phd project is to propose some new coaxial magnetic gears (CMGs) and magnetically-geared machines (MGMs), which could be introduced into the low-speed high-torque applications to solve or artfully avoid the above issues.
Firstly, the analytical model of the CMG, based on subdomain modeling technique, is built up. The magnetic behaviors in the CMG are described by Maxwell equations in terms of the magnetic vector potentials A in 2-D polar coordinates. By applying the interface constraints, the magnetic problems in the CMG could be represented by a matrix equation. The analytical solution could be achieved by using numerical computation. After that, the influence of the key design parameters on torque density and unbalanced magnetic force are investigated, respectively. However, for the CMGs in the high-torque applications, the increased unit capacity may result in significant growth of the subdomains, so that the dimension of the matrix equation becomes large. It is inevitable to increase the processing time of the analytical subdomain model, which makes the subdomain technique not present too many advantages over the FE calculation in terms of computational efficiency. Therefore, this phd project puts efforts on the matrix dimension reduction and makes attempts to make the most of the interface constraints in order to achieve a significant improvement on the computational cost.
Secondly, for ease of the integration of the CMG with electrical machines, this phd project aims at proposing a novel CMG, which will not increase the mechanical complexity after the combination with a permanent magnet (PM) brushless machine. The prominent feature of the proposed CMG is the introduction of a slotted stator. The teeth on the stator could function as the same as the modulating pole-pieces in the conventional CMG. The corresponding integrated MGM can then be achieved by inserting the armature windings into the stator slots. The configuration, harmonic analysis, and torque capability of the proposed CMG are studied in comparison with the conventional CMG. The operating principle and electromagnetic performance of the proposed MGM are investigated by dividing it into one vernier PM machine, one PM brushless machine and one proposed CMG. The results show that the developed integrated MGM exhibits good torque capability and high power factor.
Thirdly, a dual-flux-modulator CMG (DFM-CMG), characterized by high torque capability and high PM utilization, is proposed. The DFM-CMG adopts spoke-type outer PM rotor and introduces an auxiliary flux modulator placed on the outmost lay. The harmonic analysis with detailed theoretical derivation is performed to reveal that the ferromagnetic pole-shoes on the spoke-type outer PM rotor could modulate the flux density distribution as well and create a nested magnetic-gearing effect. More useful harmonics are thus generated in the air-gaps to contribute to the torque production. The effect of the auxiliary flux modulator on the flux density distribution is also studied by finite element (FE) analysis. Due to the presence of the auxiliary flux modulator, the flux leakage is suppressed and the useful harmonics are amplified. A quantitative comparison among the surface-mounted CMG (SM-CMG), spoke-type CMG (ST-CMG) and DFM-CMG is made to investigate the performance improvement of the DFM-CMG. The presence of the auxiliary flux modulator has been verified to be able to improve the torque production by FE analysis of 44% growth and experimental test of 41% growth, respectively. Finally, by adding the armature windings into the stator slots of the auxiliary flux modulator, a dual-flux-modulator MGM (DFM-MGM) is achieved. The back electromotive force, torque performance, and power factor of the DFM-MGM are investigated by the FE analysis and finally verified by the experimental test.
Department of Energy Technology
Pontoppidanstræde 111, auditorium
26.02.2018 kl. 10.00 - 27.02.2018 kl. 17.00
This year we have our sixth annual Niels Bohr Lectures where we reflect on the 5 years of our Niels Bohr Centre for Cultural Psychology and look forward to the future of Cultural Psychology.
26.02.2018 - 02.03.2018
For alle studerende på AAU i Aalborg
27.02.2018 - 02.03.2018
This four day course introduces different perspectives and techniques in visual methods.
27.02.2018 kl. 09.00 - 27.02.2018 kl. 16.00
På dette kursus vil du få viden om, hvordan man afklarer, om en bygning har et sundhedsmæssigt utilfredsstillende indeklima som følge af PCB-forurening, samt hvordan man gennemfører en kortlægning af forureningen
27.02.2018 kl. 15.00 - 27.02.2018 kl. 18.00
For alle studerende på AAU i Aalborg
28.02.2018 kl. 14.30 - 28.02.2018 kl. 16.15
The economic and political crisis in Europe has intensified the debate about the relations between citizens and politicians and how new ways of doing politics could be developed.
28.02.2018 kl. 16.00 - 28.02.2018 kl. 18.00
Seminaret er åbent for alle - bliver holdt på dansk
28.02.2018 kl. 17.30 - 28.02.2018 kl. 19.30
Arbejder du med pædagogik eller undervisning – og er du interesseret i innovative og kreative læreprocesser, der inddrager kunsten, legen og sanserne? Så har Aalborg Universitet København et nyt og fagligt interessant tilbud med et åbent fyraftensmøde, hvor kreativitetsforsker Julie Borup Jensen præsenterer potentialet i æstetiske læreprocesser og kunstintegrerende pædagogik.
01.03.2018 - 01.03.2018 kl. 07.38
International symposium at Stockholm University 13–14 September, 2018. Abstracts due 1 March, 2018. Language: English.
01.03.2018 kl. 13.00 - 01.03.2018 kl. 15.30
Laboratory for Welfare Technologies - Telehealth & Telerehabilitation, SMI, Department of Health Science and Technology, Aalborg University invites you to a research seminar on future telerehabilitation of patients with chronic diseases.
01.03.2018 kl. 16.00 - 01.03.2018 kl. 17.00
Join us for the opening of one of the largest digital works of art in Danish history.
01.03.2018 kl. 16.00 - 01.03.2018 kl. 17.00
Kom til fernisering på et af danmarkshistoriens største digitale kunstværker
02.03.2018 kl. 09.30 - 02.03.2018 kl. 17.00
Åbent Hus er arrangementet for dig, der er interesseret i en bacheloruddannelse på Aalborg Universitet. Vi står klar til at fortælle dig om vores uddannelser og vejlede, så du kan finde den uddannelse, der er rigtig for dig.
02.03.2018 kl. 13.00 - 02.03.2018 kl. 18.00
I forbindelse med Jørgen Riis Jepsens forsvar af sin doktorafhandling, inviterer Klinisk Institut til disputatsforvar af afhandlingen: Studies of upper limb pain in occupational medicine, in general practice, and among computer operators. Diagnostic contribution from manual muscle testing and assessment of cutaneous sensibility and nerve trunk mechanosensitivity.
05.03.2018 kl. 09.00 - 19.03.2018 kl. 16.00
Efteruddannelsen i radonrenovering kvalificerer dig til at få adgang til det voksende marked for radonrenovering. Underviserne er de førende eksperter fra Teknologisk Institut og Statens Byggeforskningsinstitut (SBi). Efteruddannelsen varer tre dage.