Tolerance-band modulation methods for modular multilevel converters
2013 (English)Conference paper (Refereed)
Modular multilevel converters (M2C) are increasingly used in high voltage direct current (HVDC) systems. The efficiency of M2Cs is highly related to the modulation method which determines the switching frequency and capacitor voltage ripple in the converter station. A new approach to modulation of M2C is presented in this paper. Tolerance-band methods are employed to obtain switching instants, and also cell selection. The proposed methods overcome the modulation problem for converters with few numbers of cells and also reduce the sorting efforts for cell balancing purposes while maintaining the cell-capacitor voltage limits. The evaluation is done by time-domain simulation by which the performance of each method is studied in both steady-state and transient cases. It is observed that using tolerance band methods not only reduces the switching frequency but also allows for handling severe fault cases in a grid connected system. Use of this method can reduce the switching losses and also allow for reduction of the cell capacitor size.
Place, publisher, year, edition, pages
IEEE , 2013. 1-10 p.
Capacitors;Modulation;Sorting;Switches;Switching frequency;Voltage control;HVDC;High voltage power converters;Switching losses;Voltage Source Converter (VSC)
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-134878DOI: 10.1109/EPE.2013.6632010ScopusID: 2-s2.0-84890192796OAI: oai:DiVA.org:kth-134878DiVA: diva2:668811
15th European Conference on Power Electronics and Applications (EPE), 2013
QC 201401292013-12-022013-12-012016-02-25Bibliographically approved