Capacitor Voltage Ripple Shaping in Modular Multilevel Converters Allowing for Operating Region Extension
2011 (English)In: IECON 2011: 37TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY, New York: IEEE , 2011, 4403-4408 p.Conference paper (Refereed)
The second-order harmonic in the circulating current of a modular multilevel converter (M2C) influences the capacitor voltage ripple. If no measures are taken to control it, it is not possible to operate the converter with unity modulation index. An open-loop method that precalculates the instantaneous values of the circulating current and the capacitor voltages is used, in order to control the circulating current. A desired second-order harmonic is intentionally induced in the circulating current in order to make the peak of the capacitor voltage coincide with the maximum requested voltage, aiming either to extend the limits of the instantaneous available voltage or avoid unnecessarily high capacitor voltages. A method for numerical estimation of the appropriate amplitude and phase of the induced second-order harmonic is described. The method is experimentally evaluated on a three-phase down-scaled laboratory prototype. From the experiments it was found that significantly improved operating conditions could be obtained.
Place, publisher, year, edition, pages
New York: IEEE , 2011. 4403-4408 p.
, IEEE Industrial Electronics Society. Annual Conference. Proceedings, ISSN 1553-572X
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-61342ISI: 000299032404116ScopusID: 2-s2.0-84856515329ISBN: 978-1-61284-972-0OAI: oai:DiVA.org:kth-61342DiVA: diva2:478960
37th Annual Conference of the IEEE Industrial Electronics Society, IECON 2011; Melbourne, VIC; 7 November 2011 through 10 November 2011
QC 201201172012-01-172012-01-172016-04-26Bibliographically approved