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
Harmonic Mitigation in Single Phase Mutually Commutated Converter Systems
KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.
KTH, School of Electrical Engineering (EES), Electrical Machines and Power Electronics.ORCID iD: 0000-0002-8565-4753
2006 (English)In: Proceedings of the 37th Annual IEEE Power Electronics Specialists Conference, PESC 2006, NEW YORK, NY: IEEE , 2006, 1542-1548 p.Conference paper, Published paper (Refereed)
Abstract [en]

An AC/DC converter comprising a cycloconverter and a capacitively snubbered voltage source converter (VSC), coupled by a medium frequency transformer, offers significant advantages. Bidirectional AC/DC power flow as well as voltage transformation and isolation can be achieved. By mutual commutation of the converters, soft switching can be achieved for all semiconductors, thus, link frequency can be increased, allowing smaller transformer and reduced filter components. However, the mutual commutation scheme imposed by the soft switching requirement puts constraints on the PWM pattern causing low frequency harmonics in certain operating points. It is shown that the low frequency harmonics can be eliminated for all points of operation, both in a single bridge configuration and interlaced configuration, common in AC-fed propulsion. A sub-optimal harmonic mitigation method based on a regularly sampled modulator is proposed. By proper oversampling of the reference waveforms substantial reduction of the low frequency harmonic contents can be achieved. The mitigation method is verified by circuit simulation and the feasibility to propulsion is demonstrated.

Place, publisher, year, edition, pages
NEW YORK, NY: IEEE , 2006. 1542-1548 p.
Series
IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE RECORDS, ISSN 0275-9306
Keyword [en]
Electric transformers; Harmonic analysis; Switching
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-10424DOI: 10.1109/PESC.2006.1712205ISI: 000245402503017Scopus ID: 2-s2.0-42449148709ISBN: 0-7803-9716-9 (print)OAI: oai:DiVA.org:kth-10424DiVA: diva2:217103
Conference
37th IEEE Power Electronics Specialist Conference (PESC 2006). Cheju Isl, SOUTH KOREA. JUN 18-22, 2006
Note
QC 20100723Available from: 2009-05-13 Created: 2009-05-13 Last updated: 2011-10-07Bibliographically approved
In thesis
1. On Design of a Compact Primary Switched Conversion System for Electric Railway Propulsion
Open this publication in new window or tab >>On Design of a Compact Primary Switched Conversion System for Electric Railway Propulsion
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis, a compact and light primary switched conversion system for AC-fed railway propulsion is investigated. It is characterized by soft switching of all converter stages and a source commutated primary converter comprising series connected valves. Both weight and volume of the conversion system are reduced significantly compared to a conventional system with a low frequency transformer.

The conversion system is made up of N isolated AC/DC conversion cells, each comprising a cycloconverter and a voltage source converter (VSC) coupled by a medium frequency transformer. The cells are series connected on the AC side and connected to a common DC-link. Thus, 2N+1 voltage levels can be synthesized at the AC terminal and the voltage stress on the transformer and line filter is reduced compared to a one cell solution. Series connection of semiconductor valves allows independent choice of blocking voltage and number of converter cells. Choosing two converter cells is an attractive compromise. Five level output reduces the harmonic distortion and simplify transformer and line filter design while keeping the complexity of the conversion system low.

The mutually commutated converter (MCC) allows a transformer frequency in the range of 4 to 8 kHz without derating the line side converter due to zero voltage switching of the VSC. Modern magnetic materials, like high silicon steel, amorphous and noncrystalline materials allow design of the transformer with high efficiency at elevated frequencies.

In a 15 kV system, the peak voltage at the catenary is typically beyond 32 kV which is far beyond the voltage capability of currently available semiconductors. Therefore, several semiconductors are connected in series. Favourable commutation conditions and a new gate drive arrangement allow snubberless commutation of the primary converter stage. Thus, the primary converter can be highly integrated, reducing both weight and volume. The conversion system can be placed on the roof or in the underframe without compromising efficiency or vehicle performance.

The feasibility of the conversion concept has been demonstrated by means of a down-scaled prototype. Snubberless commutation of series connected valves is demonstrated.

Place, publisher, year, edition, pages
Stockholm: KTH, 2009. viii, 75 p.
Series
Trita-EE, ISSN 1653-5146 ; 2009 : 29
Keyword
Isolated AC/DC converter, Mutual commutation, Soft Switching, Cyclo converter, Medium-Frequency Transformer, Electric Railway Propulsion
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-10428 (URN)978-91-7415-327-9 (ISBN)
Public defence
2009-06-05, D3, Lindstedtvägen 5, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
QC 20100723Available from: 2009-05-18 Created: 2009-05-13 Last updated: 2010-07-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Norrga, Staffan

Search in DiVA

By author/editor
Kjellqvist, TommyNorrga, Staffan
By organisation
Electrical Machines and Power Electronics
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 106 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