Analysis of arm current harmonics in modular multilevel converters with main-circuit filters
2012 (English)In: International Multi-Conference on Systems, Signals and Devices, SSD 2012 - Summary Proceedings, IEEE , 2012Conference paper (Refereed)
In a modular multilevel converter the circulating current that flows through each phase leg can affect the performance and efficiency of the converter. If measures are not taken to control the circulating current, it will inevitably contain a second-order harmonic. There are various solutions for eliminating this second-order harmonic. One of the proposed solutions includes a main-circuit filter that is tuned to block the second-order harmonic in the circulating current. This paper presents an analytical relation between the ac-side current and the higher-order harmonics in the circulating current when such a filter is used. It is found that when third-order harmonic injection is used, a large fourth-order harmonic component may appear in the circulating current. This is verified by simulating a 32-MVA converter designed for grid connected applications. The simulation results support the conclusion that it is essential to take this effect into consideration when designing the main-circuit filter.
Place, publisher, year, edition, pages
IEEE , 2012.
AC-side, Analytical relations, Circulating current, Current harmonics, Fourth-order, Grid-connected, Harmonic components, Harmonic injection, Higher order harmonics, Modular multilevel converters, Second orders, Third-order
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-92265DOI: 10.1109/SSD.2012.6197915ScopusID: 2-s2.0-84861630463ISBN: 978-146731590-6OAI: oai:DiVA.org:kth-92265DiVA: diva2:513060
9th International Multi-Conference on Systems, Signals and Devices, SSD 2012;Chemnitz;20 March 2012 through 23 March 2012
QC 201208022012-03-302012-03-302016-04-21Bibliographically approved