Open AccessSwitching function analysis of half‐ and full‐bridge modular multi‐level converters for HVDC applications
Author(s) -
Deore Sawata R.,
Darji Pranav B.,
Kulkarni Anil M.
Publication year - 2013
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2012.0034
Subject(s) - converters , modular design , function (biology) , bridge (graph theory) , computer science , electronic engineering , hvdc converter station , half bridge , electrical engineering , engineering , capacitor , voltage , medicine , evolutionary biology , biology , operating system
This study presents a theoretical analysis of half‐ and full‐bridge modular multi‐level converters for HVDC transmission applications. The constraints and the degrees of freedom in the choice of switching functions, and the harmonic content of the sum and difference of arm voltages and currents, are highlighted by the analysis. The authors prove that under balanced switching conditions, dc and even harmonic components are absent from the difference variables and odd harmonics are absent from the sum variables, whereas the pole voltages are free from harmonics. Using an energy function approach, it is shown that the sorting strategy for module voltage balancing is stable and practically independent of the dynamics of the rest of the system. The module voltages settle down to a band around the average value because of the finite switching frequency, for which an upper bound is provided.