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

Direct link
Flywheel energy and power storage systems
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
2007 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 11, no 2, 235-258 p.Article in journal (Refereed) Published
Abstract [en]

For ages flywheels have been used to achieve smooth operation of machines. The early models where purely mechanical consisting of only a stone wheel attached to an axle. Nowadays flywheels are complex constructions where energy is stored mechanically and transferred to and from the flywheel by an integrated motor/generator. The stone wheel has been replaced by a steel or composite rotor and magnetic bearings have been introduced. Today flywheels are used as supplementary UPS storage at several industries world over. Future applications span a wide range including electric vehicles, intermediate storage for renewable energy generation and direct grid applications from power quality issues to offering an alternative to strengthening transmission. One of the key issues for viable flywheel construction is a high overall efficiency, hence a reduction of the total losses. By increasing the voltage, current losses are decreased and otherwise necessary transformer steps become redundant. So far flywheels over 10 kV have not been constructed, mainly due to isolation problems associated with high voltage, but also because of limitations in the power electronics. Recent progress in semi-conductor technology enables faster switching and lower costs. The predominant part of prior studies have been directed towards optimising mechanical issues whereas the electro technical part now seem to show great potential for improvement. An overview of flywheel technology and previous projects are presented and moreover a 200 kW flywheel using high voltage technology is simulated.

Place, publisher, year, edition, pages
2007. Vol. 11, no 2, 235-258 p.
Keyword [en]
Cost lowering, Semiconductor materials, Engineering design, Performance, Numerical simulation, Mathematical model, Flywheel, Energy storage
National Category
Engineering and Technology
URN: urn:nbn:se:uu:diva-94420DOI: 10.1016/j.rser.2005.01.004ISI: 000241289600003OAI: oai:DiVA.org:uu-94420DiVA: diva2:168259
Available from: 2006-04-28 Created: 2006-04-28 Last updated: 2016-04-11Bibliographically approved
In thesis
1. Electric Power Generation and Storage Using a High Voltage Approach
Open this publication in new window or tab >>Electric Power Generation and Storage Using a High Voltage Approach
2006 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Production and consumption of electricity have grown enormously during the last century. No mater what the primary source of energy is, almost all generation of electricity comes from conversion of a rotational movement in a generator. The aim of this thesis is to see how high voltage technology influence production and storage of electricity. Power flow in the generators used to convert mechanical movement to electric energy is analyzed using Poynting‘s vector. The impact of new generator technology for efficient extraction of hydroelectric power is shown. Simulation of a large permanent magnet turbo generator is presented. A flywheel storage system for electric vehicles utilizing high voltage technology is also presented. In pulsed power applications, a cheap method for intermediate storage of energy during milliseconds, which enables an inductive primary storage is presented and experimentally tested.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2006. 91 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 173
Engineering physics, Flywheel, Generation, Generator, High Voltage, Power flow, Poynting, Teknisk fysik
urn:nbn:se:uu:diva-6833 (URN)91-554-6552-8 (ISBN)
Public defence
2006-05-19, Polhemsalen, Ångström, Lägerhyddsvägen 1, Uppsala, 13:15
Available from: 2006-04-28 Created: 2006-04-28Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Bolund, BjörnBernhoff, HansLeijon, Mats
By organisation
In the same journal
Renewable & sustainable energy reviews
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
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

Altmetric score

Total: 358 hits
ReferencesLink to record
Permanent link

Direct link