Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • 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
Comparison of Cascaded Multilevel Converter Topologies for AC/ AC Conversion
KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.ORCID iD: 0000-0001-8891-5659
KTH, School of Electrical Engineering (EES), Electrical Energy Conversion. (High Power Electronics)ORCID iD: 0000-0002-8565-4753
2014 (English)In: 2014 International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014, IEEE Computer Society, 2014, p. 1087-1094Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a simplified qualitative comparison of previously presented cascaded multilevel converter topologies for ac-ac conversion with particular emphasis on motor drive applications. Performance criteria such as the pulsation of the stored energy in the cell capacitors and the total required semiconductor rating are derived by analytical methods. The main conclusion is that the back-to-back connected modular multilevel converter operates best at synchronous speed, whereas the modular matrix converter and Hexverter are better suited for low-frequency output. However, by injecting circulating currents in the phase arms the operating region can be extended for all of the studied topologies.

Place, publisher, year, edition, pages
IEEE Computer Society, 2014. p. 1087-1094
Series
International Conference on Power Electronics, ISSN 2150-6078
Keywords [en]
Matrix converters, Power converters, Topology, Cascaded multilevel converter, Circulating current, Modular matrix converters, Modular multilevel converters, Motor drive applications, Operating regions, Performance criterion, Synchronous speed
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-153758DOI: 10.1109/IPEC.2014.6869722ISI: 000347109201005Scopus ID: 2-s2.0-84906662220ISBN: 978-1-4799-2705-0 (print)OAI: oai:DiVA.org:kth-153758DiVA, id: diva2:753571
Conference
7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014, Hiroshima, Japan, 18 May 2014 through 21 May 2014
Funder
StandUp
Note

QC 20141010

Available from: 2014-10-08 Created: 2014-10-08 Last updated: 2016-02-12Bibliographically approved
In thesis
1. Modeling and Design of Modular Multilevel Converters for Grid Applications
Open this publication in new window or tab >>Modeling and Design of Modular Multilevel Converters for Grid Applications
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis aims to bring clarity to the dimensioning aspects and limiting factors of the modular multilevel converter (MMC). Special consideration is given to the dc capacitors in the submodules as they are a driving factor for the size and weight of the converter. It is found that if the capacitor voltages are allowed to increase by 10% the stored energy must be 21 kJ/MW in order to compensate the capacitor voltage ripple. The maximum possible output power can, however, be increased by injecting a second-order harmonic in the circulating current.

A great advantage of cascaded converters is the possibility to achieve excellent harmonic performance at low switching frequencies. Therefore, this thesis also considers the relation between switching harmonics, capacitor voltage ripple, and arm quantities. It is shown that despite subharmonics in the capacitor voltages, it is still possible to achieve periodic arm quantities. The balancing of the capacitor voltages is also considered in further detail. It is found that it is possible to balance the capacitor voltages even at fundamental switching frequency although this will lead to a comparably large capacitor voltage ripple. Therefore, in order to limit the peak-to-peak voltage ripple, it is shown that a predictive algorithm can be used in which the resulting switching frequency is approximately 2–3 times the fundamental frequency.

This thesis also presents two new submodule concepts. The first submodule simply improves the trade-off between the switching frequency and capacitor voltage balancing. The second submodule includes the possibility to insert negative voltages which allows higher modulation indices compared to half-bridge submodules.

A brief comparison of cascaded converters for ac-ac applications is also presented. It is concluded that the MMC appears to be well suited for ac-ac applications where input and output frequencies are close or equal, such as in interconnection of ac grids. In low-frequency applications such as low-speed drives, however, the difficulties with handling the energy variations in the converter arms are much more severe in the MMC compared to the other considered topologies.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. p. x, 55
Series
TRITA-EE, ISSN 1653-5146 ; 2014:045
Keywords
Modular multilevel converter, feed-forward control, modulation, switching frequency, energy storage
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-153762 (URN)978-91-7595-293-2 (ISBN)
Public defence
2014-11-03, Sal F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20141010

Available from: 2014-10-10 Created: 2014-10-08 Last updated: 2016-02-26Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Norrga, Staffan

Search in DiVA

By author/editor
Ilves, KalleBessegato, LucaNorrga, Staffan
By organisation
Electrical Energy Conversion
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 194 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • 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