uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Eigen frequency and damping in a passive magnetic bearing system
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.ORCID iD: 0000-0002-5736-5700
Univ. Fed. Rio de Janeiro, Brazil.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.ORCID iD: 0000-0002-5361-7739
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
Show others and affiliations
2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

A complete passive magnetic bearing system, consisting in a Permanent Magnet radial bearing and a Superconductive Magnetic Bearing has been simulated and constructed. The forces in both types of magnetic bearings are not linear. The non-linear behavior has been implemented in a FEM model and compared with linear models. A spin down test has been conducted to the built system and the Eigen frequencies have been recorded. The Eigen frequencies calculated with and without the non-linear behavior implemented in the model are very similar.

Place, publisher, year, edition, pages
2016.
Keyword [en]
Flywheel, Permanent Magnet Bearing, Superconductive Magnetic Bearing, Eigen frequencies, Passive Bearings, Numerical Analysis, FEM
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:uu:diva-305350OAI: oai:DiVA.org:uu-305350DiVA: diva2:1037404
Conference
15th International Symposium on Magnetic Bearings (ISMB15), 3-6 August 2016. Kitakyushu Japan
Available from: 2016-10-14 Created: 2016-10-14 Last updated: 2017-04-06Bibliographically approved
In thesis
1. Electrified Integrated Kinetic Energy Storage
Open this publication in new window or tab >>Electrified Integrated Kinetic Energy Storage
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The electric car is a technically efficient driveline, although it is demanding in terms of the primary energy source. Most trips are below 50 km and the mean power required for maintaining speed is quite low, but the system has to be able to both provide long range and high maximum power for acceleration. By separating power and energy handling in a hybrid driveline, the primary energy source, e.g. a battery can be optimised for specific energy (decreasing costs and material usage). Kinetic energy storage in the form of flywheels can handle the short, high power bursts of acceleration and decceleration with high efficiency.

This thesis focuses on the design and construction of flywheels in which an electric machine and a low-loss magnetic suspension are considered an integral part of the composite shell, in an effort to increase specific energy. A method of numerically optimising shrink-fitted composite shells was developed and implemented in software, based on a plane stress assumption, with a grid search optimiser. A composite shell was designed, analysed numerically and constructed, with an integrated permanent magnet synchronous machine. Passive axial lift bearings were optimised, analysed numerically for losses and lift force, and verified with experiments. Active radial electromagnets optimised for high stiffness per ohmic loss were built and analysed in terms of force and stiffness, both numerically and experimentally. Electronics and a high-speed measurement system were designed to drive the magnetic bearings and the electric machine. The control of these systems were implemented in an FPGA, and a notch-filter was designed to suppress eigenfrequencies to achieve levitation of the rotor. The spin-down losses of the flywheel in vacuum were found to be 1.7 W/Wh, evaluated at 1000 rpm.

A novel switched reluctance machine concept was developed for hollow cylinder flywheels. This class of flywheels are shaft-less, in an effort to avoid the shaft-to-rim connection. A small-scale prototype was built and verified to correspond well to analytical and numerical models, by indirect measurement of the inductance through a system identification method.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. 93 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1504
Keyword
flywheel energy storage, magnetic bearings, carbon composite
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-319622 (URN)978-91-554-9891-7 (ISBN)
Public defence
2017-06-08, Ång/80101, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Funder
StandUpSwedish Energy Agency
Available from: 2017-05-15 Created: 2017-04-06 Last updated: 2017-05-16

Open Access in DiVA

fulltext(655 kB)89 downloads
File information
File name FULLTEXT01.pdfFile size 655 kBChecksum SHA-512
2804ec817dd638df2d0e714ad2d53e6b9c3654aafa00f6fdafa751c8a0960df99df876755dbb7d6b9ceae32a3242aa36a1a6db2d41ed59e5c0836080f1850af8
Type fulltextMimetype application/pdf

Authority records BETA

Hedlund, Magnusde Santiago, JuanGoncalves de Oliveira, Janaína

Search in DiVA

By author/editor
Hedlund, Magnusde Santiago, JuanGoncalves de Oliveira, Janaína
By organisation
Electricity
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 89 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 625 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf